FIFTEENTH ANNUAL REPORT - International Nuclear ...

ATOMIC ENERGY BOARDRepublic of South Africa

FIFTEENTHANNUAL REPORT

The Rotating Rig used for irradiating material samples at room température.

HIERDIE VERSLAG IS OOK IN AFRIKAANS BESKIKBAAR

ISBNO 86960 147 4

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ATOMIC ENERGY BOÂKD

CHA1RSVIAW:DR.A.J.A. ROUX, PRESSDEMT

MEMBERS

Dr. C. v. d. M. BRINKPresident, Council for Scientific and Industrial Research(Appointed on 5th Oct., 1971 )

Mr. J. P. COETZEEGeneral Manager, S.A. Iron and Steel Industrial CorporationLimited

Mr. B. G. FOURIESecretary for Foreign Affairs

Mr. C. J. F. HUMANManaging Director, Federale Volksbeleggings, BeperkDr. G. S. J. KUSCHKEChairman, Industrial Development Corporation of S.A.Limited (Deceased on 27th July, 1971 )

Industrial Research

Mr. H. S. MABINExecutive Director, Association of Chambers of Commerceof South AfricaDr. S. M. NAUDÉPresident, Council for Scientific and(Retired on 4th Oct., 1971)

Prof. S. F. OOSTHUIZENProfessor of Radiology, University of PretoriaMr. J. W. SHILLINGChamber of Mines of South Africa (Chairman, Nuclear FuelsCorporation of South Africa (Pry) Limited)

Dr. R. L. STRASZACKERChairman, Electricity Supply CommissionMr. N. J. UYSSecretary for Mines

EXECUTIVE COMMUTEE

CUP 2 RM AM: DR. A. J. À. ROUX

MEMBERS

Dr. C. v. d. M. Brink(From 15th Oct., 1971)

Dr. G. S. J. Kuschke(Deceased on 27th July, 1971 )

Dr. S. M. Naudé(Retired on 4th Oct., 1971 )

Mr. J. W. ShillingDr. R. L. StraszackerMr. N. J. Uys

Dr. A.J.A. koux. President of the Board.

Dr.J.P.B. Hugo. Deputy President. Dr. L. Alberts. Vice President.

Dr. A. J. A. ROUX: PRESID

Dr. W. L. GrantDeputy President (To 31 st March, 1971)

Dr. J. P. B. HugoDeputy President

Dr. L. AlbertsVice-President (From 1st April, 1971)

Mr. C. MöllerManager: Technical

Mr. J. O. TattersallManager: Licensing

Mr. J. G. W. van ZylManager: Administration

IS M T ^

SUMMARYINVISTMATION OF NUCLEAR FUEL RESOURCESOCCURRENCE OF OTHER NUCLEAR MATERIALSTHE EXTRACTION OF URANIUM FROM OREURANNIM COMPOUNDSFUEL MANUFACTUREANALYTICAL METHODS

MUCLKÄR FÖWSR . •ECONOMIC STUDIESREACTOR DEVELOPMENTSODIUM STUDIESTHE DEVELOPMENT OF REACTOR MATERIALSENVIRONMENTAL STUDIES ON THE LAND AND IN THESEA AROUND DUINEFONTEINPEACEFUL APPLICATIONS OF NUCLEAR EXPLO8IONS

APPLiCÅTSO^ OF RÄ?MOi8OT0PES AMP-RmïÂTîQW - " -ISOTOPE APPLICATION AND PROMOTIONNATURAL ISOTOPES AND TRACERSISOTOPE PRODUCTIONIRRADIATION SERVICESREGULATORY CONTROLUSERS OF RADIOACTIVE MATERIALCOURSES 'IMPORTSE X P O R T S ' • ' ' _ -, '•, ,.-• ' •_

H £ Â L T M AND SAFETY '

ROUTINE MEDICAL EXAMINATIONS, RADIATION PROTECTION AND CONTROLPROTECTION ON THE SSTERADIOACTIVITYSAFETY

FUWfMMENTAL 8TÜSSES 'SUMMARYNUCLEAR PHYSICSTHEORETICAL PHYSICSCHEMISTRY .EXTRACTION METALLURGYPHYSICAL METAUUMYMBMCAL AND BIOLOGICALISOTOPES AND RADIATIONGEOLOGY

TECHNICAL ACTIVITIIsS " • ' ' '•R'EèEARCH REACTOR . . , . ' ' • -REACTOR OPERATIONRBACTOft SYSTEMS AND COMPONENTSREACTOR FACILmM .9ETBHMINATION OF REACTOR PARAMETERS ANDSPECIAL TESTSIRRADIATIONS AND EXPERIMENTSREACTOR FUEL

GENERALFACILITY FOR THE AUTOMATIC COLLECTION ANDANALYSIS OF NUCLEAR PHYSICS DATADEVELOPMENT OF NUCLEAR INSTRUMENT MODULES(NIM)OPERATING SYSTEM FOR MINI-COMPUTERSMAGNETIC FIELD STABILIZATION BY NMREMERGENCY CONTROL CENTREMAINTENANCE

OTHER SHS SEOPERATIONANALYTICAL SERVICESENGINEERING SERVICESCOMPUTERSERVICES

FOURTH INTERNATIONAL CONFERENCE ON THEPEACEFUL USES OF ATOMIC ENERGYINTERNATIONAL ATOMIC ENERGY AGENCYINTERNATIONAL NUCLEAR INFORMATIONSYSTEM (INIS)OVERSEAS VISITS •VISITORS FROM OVERSEASVISITS TO PELINDABALIBRARY SERVICESSCIENTIFIC GATHERINGS

STAFF- - : . " - . - -• . . .• ' >'SAFETY CRITERIA .SAFETY ASSESSMENTCOMPONENT AND PLANT RELIABILITYDATA PROCESSING AND STORAGECONTROL OF DEVELOPMENT AROUND REACTOR SITESNUCLEAR SAFETY ADVISORY COMMITTEE

S T A F F ; ' • \ ' . - - • . . • . • - . . ' . • • • • ' • ' . '. ;

FINANCIAL AID TO UNIVERSITIES ANDRESEARCH INSTITUTIONS

COMMITTEES OF THE BOARD DURING 1S71

APPENDIX 6 ' : - ' . ."•'V "LIST OF PUBLICATIONS BY STAFF MEMBERS AND BURSARSOFTHEBOARD _

F I N A M C & S - . " " / , '•/-• .; V • .'_., •' ..

A P P E N D i x c " " ,. .' . . • • . ' • • - . ;1. CONSOLIDATED BALANCE SHEET •2. ADMINISTRATION ACCOUNT \3. RESEARCH FUND ' 'CONTRUMiTORS TO THE «7S/71RSSKARCH PROGRAMME

Pelindaba's Main Entrance building, v/hkh was inaugurated by theMinister'ttf'Mines, Dr. the Hun.CoreldtWet, during the year.

THE ECONOMIC RIPPLEJust as the mediaeval castles of Europe gave way before the

onslaught of the Industrial Revolution so too is the popularly-held misconception of science as a realm of ivory towerspeopled by remote and dedicated scientists out of touch withreality, being replaced by the realisation that research is anessential part- of industry and commerce. The Atomic EnergyBoard's work is a clear pointer to this inescapable fact-thedevelopment of suitable extraction processes for newly dis-covered uranium deposits; the package irradiation pla.noffering an eagerly sought-after sterilisation service, whichbefore very long will be in continuous operation; the develop-ment of a computer programme for analysis of the SouthAfrican electricity network; geological mapping and investi-gation leading to discoveries of mineral deposits of potentialeconomic importance. These and other projects perhaps less

spectacular, illustrate the Board's awareness of the funda-mental importance of economics in its contribution to thecountry's progress and development.

The creation of the Uranium Enrichment Corporation aiSouth Africa Limited in April 1971, while it brought to aformal end the Atomic Energy Board's direct responsibilityfor research and development on uranium enrichment, cm-phasised the deep significance of the new process. Principallyaffected is the Board's approach to nuclear power generationstudie while it has added a further dimension to the deter-mination and sophisticated exploitation of the country'suranium reserves-reserves which in the course of lhc yearreached a new level of 300 000 tons recoverable at less thanS10/lb. The economic studies related to electricity generation,especially from the point of view of nuclear generation, arc-now reaching out towards the end of the century. Slavingreviewed the economics of advanced reactor systems.

Overall, the applied nature of Pelindaba's efforts emergesclearly but the essence of successful research is engenderedby relevant fundamental studies. A brief glance at theseactivities shows that their importance is well appreciatedand that the Atomic Energy Board's efforts to keep SouthAfrica in the vanguard of peaceful nuclear applications, arefirmly built on a sound foundation of basic research.

From the plain fact of South Africa's substantial uraniumreserves, the ripple of nuclear research born some twelveyears ago, is building up to a wave washing over more andmore aspects of the country's economic life. Each year brimjsincreased public realisation that the benefits of nuclear energyoK indispensable to continued progress in industry, medicineand agriculture, and the Board takes pride in fulfilling ilsobligation to keep the Republic in the front line in mattersnuclear.

RESEARCHNUCLEAR MATERIALS

SUMMARYA critical re-assessment of South Africa's uranium reserves

was undertaken, and as a result of new discoveries, higherextraction efficiencies and the development of improved ex-traction processes reasonably assured reserves of U3O,, re-coverable at up to 10 dollars per pound, were revaluated at300 000 short tons. The recently discovered uranium depositin the Omaruru district was mapped and reported on, whilegeological mapping of an area containing many mineralisedpegmatites in Namaqualand reached completion stage. Acontinuous ion-exchange unit at the Rössing pilot plant isbeing tested as an alternative to other techniques for therecovery of uranium. Erection of the demonstration resin-in-pulp plant at West Driefontein was completed. A methodwas developed for trv determination of both acid-soluble andacid-insoluble uranium in ores. The irradiation of 2% enricheduranium spheres in the Chouca-P rig was successfully com-pleted. Suitable irradiation rigs for other materials irradiationprojects have been ordered. The development of various analy-sis techniques was continued.

INVESTIGATION OF NUCLEAR FUELRESOURCES

URANIUM RESERVESSouth Africa's uranium output has in the past depended

almost entirely on current gold mining operations. Workingcosts have risen enormously during the past two decades,and for this reason a critical re-assessment of South Africa'suranium reserves was undertaken during the year. The lifeof the gold mines based on projections of annual productionof gold and by-product uranium over the next 25 years wastaken into account in estimating the reserves of uranium inthe Witwatersrand basin. The exercise also entailed estimatesof uranium in the basal sedimentary rocks of the DominionReef System west of Klerksdorp, Transvaal, which have beensystematically explored by core drilling during the past threeyears. Also included in the study, was the uranium containedin the low-grade uranothorianite associated with the copper-biotite-magnetite deposits encountered in the carbonatite-phosphorite-pyroxerite intrusive pipe at Phalaborwa (thisuranium is being recovered as a by-product) as well as uraniumcontained in a low grade deposit of alaskitic rocks at Rössingin the Swakopmund District, South-West Africa, which maybe mineable by open-pit methods.

Until recently uranium reserves, which could be economi-cally exploited, were estimated at 200 000 short tons. Afterrevaluation, the figure has now risen to 300 000 short tons forreasonably assured reserves of U3O8 recoverable at up to10 dollars per pound. The increase has resulted from newdiscoveries in both the Republic and South-West Africa, aswell as from the achievement of higher extraction efficienciescoupled with the development of improved extractionprocesses.

Rössing Area, Swakopmund DistrictA bursar of the Atomic Energy Board completed the field

mapping of an area of 1 500 square kilometres in the areaaround the confluence of the Khan and Swakop rivers andcontinued with the laboratory investigations and plotting ofdata obtained during field work. The final geological mapwhich shows the distribution of all radioactive pegmatiteshas been compiled and printed. It will accompany the geolo-gical report now in the course of preparation. The map alsoindicates a new area of mineralised radioactive pegmatitesnot covered by the aerial radiometric survey and thereforepreviously unknown. It was traced by means of a groundscintillation survey, and awaits further exploration.

Zoned pegmatites are well developed in the central andeastern parts of the area. They may be subdivided into border,wall, intermediate and core zones and contrast with the alas-kite type which is the ore-bearer at Rössing.

Cape Cross Area, Omaruru DistrictThe recently discovered uranium deposit near Cape Cross

was mapped and reported on. The work involved detailedradiometric and geological surveying of 12 000 hectares ofground mostly covered by a thin veneer of surface deposits.A series of narrow mineralised veins consisting of a mixtureof carnotite and gypsum in weathered granite contained up totwo per cent U3O8. Owing to the small size and limitednumber of veins that could be traced the deposit docs notconstitute an economical proposition at this stage.

Pilansberg, Rustenburg DistrictAerial radiometric anomalies, which have long been

known to the Board, were investigated. Anomalies arc dueto veins present in the alkaline rocks containing from 15 - 20per cent rare-earths and also to thin bands of lava and tuffcontaining about 2,6 per cent rare-earths. These occurrencesare being further investigated by a mining company.

Aerial Radfometric AnomaliesThe Geological Survey placed contracts for gamma ray

specrrometric and magnetic aerial surveys for specified areasin Transvaal and South-West Africa. In the former case thesurvey will cover approximately 50 000 square kilometres ata line spacing of 1 000 metres and a ground clearance of150 metres. In South-West Africa an area of 11 480 squarekilometres has been completed, but the survey did not revealany impressive new radio-activity anomalies.

OCCURRENCE OF OTHER NUCLEARMATERIALS

PEGMATITE INVESTIGATIONSGeological mapping of pegmatites, and fundamental

research into their origin, form, structure, mineralisation andextraction metallurgy, continued unabated by officers of boththe Board and the National Institute for Metallurgy.

The geological mapping of pegmatite terrains by a bursarin Namaqualand and an officer of the Board in South-WestAfrica were completed and detailed laboratory studies arenow being undertaken. The large Witkop pegmatite at Tanta-lite Valley in South-West Africa was mapped in detail and anumber of boreholes drilled in order to estimate the reservesof tantalum, beryllium and bismuth minerals present. Theobject of this exercise is to erect a central processing plantto extract all the valuable minerals from the pegmatites assoon as an adequate reserve has been proved.

ALUMINIUMThe following information was supplied by the Geological

Survey, Department of Mines.Results of chemical analyses of latentie «oils from the

Duiwelskloof area proved disappointing. Likewise, resultsof 30 samples taken of red soil, derived from felsite andgranophyne from the Groblersdal and Marble Hall areas,proved negative.

Preliminary X-ray analyses of lateritic soils between MountFrere and Mount Ayliff and the Weza Forestry Reserve nearHarding indicated the presence of gibbsite. Investigations areproceeding.

NICKELDetailed mapping and exploration diamond drilling of

an ultramafic gabbro body were completed near Warmbad,South-West Africa. The cores contained sulphides of nickel,copper, iron and cobalt ore. Fourteen exploration boreholeswith a total depth of more than 3 000 metres were drilled.Promising values over thicknesses of mineralised ore ofmore than 50 metres, at depths between 100 and 200 metresbelow the surface, were proved in four boreholes. Averagevalues for nickel and copper for mineralised core varied from0,21 to 0,58 and from 0,30 to 0,50 per cent respectively.

THE EXTRACTION OF URANIUM FROMORE

The work described in this section is being undertaken bythe Board, working in close collaboration with the NationalInstitute for Metallurgy <NIM).

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RÖSSING PROJECTA close association was maintained with all aspects of the

work at Rossi ng and valuable assistance was given in thedesign and operation of the pilot plant. A continuous ion-exchange plant, based on the multistage fluidized-bed tech-nique of Cloete and Streat, was designed and installed at theRössing pilot plant and was tested together with other tech-niques for the recovery of uranium.

THE EXTRACTION AND RECOVERY OFURANIUM FROM WITWATERSRAND ORES

The Felix project, which was aimed at improvements inthe extraction efficiency at uranium plants, was closedbecause none of the South African uranium producers wereable to benefit from the increased production made possibleby adopting the process because of the restricted market foruranium. However, a limited amount of work is being donefor one uranium producer who is investigating the possibilityof replacing manganese dioxide with ferric sulphate.

Experimental work on the production of ferric sulphateand sulphuric acid in a Frings Aerator was completed. Theresults provide sufficient information fora thorough economicassessment of the process and for the development of amathematical model of the aerator operation and the kineticsof the reaction mechanism. The information obtained will beused for the planning of experiments on other systems in-volving the hydrometallurgical treatment of ores containingcopper-and zinc.

The spiral heat exchanger for recovery of heat from acidpulps was moved to NIM, where a comprehensive investiga-tion is now being undertaken under more rigorously con-trolled conditions than were possible at uranium plants.Initial cost calculations show that the use of spiral heatexchangers in uranium plants would be justified only if theseplants adopt the higher leaching temperatures and the higherliquid-to-solid ratios of the Felix process.

RESIN-IN-PULP AND CONTINUOUS IONEXCHANGE

The erection of the demonstration resin-in-pulp plant atWest Driefontein was completed, and three-shift operationhas started. It was shown that pulp will flow through theplant for a period of weeks without the Relix pachucas beingblocked by accumulated sand. Resin added to the pulp wasfound to lie in a band near the surface during normal agitation.Collection of this resin in a form suitable for feeding to theelution column was unsatisfactory, but the installation of anadditional gyratory screen has improved matters considera-bly. Tests have shown that the resin becomes fully loadedin contact with the pulp in the pachucas.

Experience was gained in the hydraulic operation of aCloete/Streat multistage fluidized-bed continuous ion exchange<CCIX) column with a diameter of approximately 2 metreswhich was built at N1M. Several useful modifications to theoriginal design and method of control were developed, andpatents were applied for.

A prototype industrial CCIX column was installed andoperated at the Rössing pilot plant. Theoretical modelling ofthe CCIX process is being carried out and has led to thedevelopment of important criteria for the design of suchplants from simple laboratory data. It was shown that un-steady-state models correspond more closely to the realsystem than do the models previously used.

URANIUM COMPOUNDSThe work described in this section has been undertaken by

the Board, working in close collaboration with the NationalInstitute for Metallurgy and the Nuclear Fuels Corporationof South Africa (NUFCOR).

URANIUM FLUORIDESAn investigation was carried out into the removal of molyb-denum during the various processing steps both at uraniumplants and at the NUFCOR Works to establish whether iheneed for a distillation step in the production of UF, directfrom Purlex ammonium diuranate (ADU) without tributylphosphate (TBP) purification can be eliminated. At thisstage it is not possible to recommend to those mines thatproduce ADU with a high molybdenum content, what theyshould do to reduce the molybdenum content of their ADUto an acceptable level.

Work continued in which batches of ADU from Purlexplants were converted to UF4 in the production unit" at theNUFCOR Works. Throughput rates and conversion efficien-cies were found to depend on the nature of the feed materialand the operating conditions in the reactor.

FUEL MANUFACTURESouth Africa's first nuclear power station will probably

come into operation towards the end of this decade. Witha view to eventual local production of reactor fuel, theBoard is investigating the manufacture and properties ofuranium oxide, as well as its behaviour under irradiationconditions. In view of the increasing importance of fastbreeder reactors, work is also being done on the developmentof advanced fast reactor fuels.

URANIUM OXIDESUranium dioxide is the major nuclear fuel and is likely to

remain so for many years to come. During the manufactureof UO2 fuel higher oxides are likely to be formed and aknowledge of these is of considerable importance. Thereforea programme of work on the preparation of various oxidesand a r:udy of their interrelationships was started.

It was found that the oxidation mechanism of UO2 andother uranium oxides depends largely on the particle size.Extremely finely divided oxides were prepared by decompo-sition of uranyl oxalate, and their stoichiometric behaviourwas studied in different atmospheres on the Mettlcr thermo-balance.

It has been claimed that metastable tetragonal crystalphases in the composition range UO23 to UO24 are formedby oxidation of UO2 below 200°C. However, the nature ofthe low temperature oxidation products is still not clear.

Stoichiometrically pure U3O7 was prepared by decompo-sition of uranyl oxalate in argon. The oxide U3O7 was con-verted to sintered U,OS with a structure similar to UO2 byheating to 950°C. The sintered product is stable in air atroom temperature.

Reactive UO2, made from uranyl oxalate by reduction inhydrogen, was oxid'sed completely to UO3 below SOCC atatmospheric pressure. Infrared spectra indicate that thecrystal structure of this UO3 is unusual. Heating it above500°C leads first to UO2>, with a structure similar to n-UO3 asan intermediate step and then to U3O,. U3O, is a usual end-product in gravimetric analysis.

Only one intermediate mass step, and that in the rangeUO2-S to VO2ft was found by heating VO2+X with mediumsurface areas (approx. 5mVg) in air or oxygen to U3O,. Nosuch intermediate step was recorded when using sinteredstarting material with a much smaller surface area.

IRRADIATION STUDIESThe object of these studies is to determine the behaviour

under irradiation conditions of reactor fuels and constructionmaterials. There arc three main projects in this field.

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THE IRRADIATION OF 2% ENRICHEDURANIUM SPHERES IN THE CHOUCA-PRIG

This irradiation experiment was approved by the SafetyCommittee early in the year. Subsequent examination byneutron radiography of the rig, which had been irradiatedfor 36 hours during commissioning tests the year before,revealed a partial meltdown of the uranium spheres in oneof the capsules with which the rig had been loaded. It waspostulated that this was the result of improper handling ofthe capsules during sodium filling, causing a gas bubble tobe trapped in the vicinity of the particular spheres, and thatthis gas bubble was expelled under the influence of the hightemperatures which caused melting during the initialirradiation.

The rig was therefore irradiated again for a short periodand re-examined. No further deterioration was found, andlong-term irradiation was therefore initiated which pro-gressed very satisfactorily. The rig was removed from thereactor and placed in the storage pool for a month-longcooling period before removal to the hot cells for post-irradiation examination early in the new year.

IRRADIATION OF LOCAL STAINLESSSTEELS IN THE CHOUCA-0 RIG

A project was initiated during the year to study thesuitability of locally produced stainless steels as a reactorconstructional material. A Chouca-0 irradiation rig has beenordered for this purpose. The rig will be inserted in a specialfuel element designed to enhance the fast neutron flux towhich the steel samples are exposed, thus allowing therequired neutron dose to be attained in a shorter time.

A preliminary design for a capsule to contain the stainlesssteel specimens was made and heal transfer studies on thisdesign are in progress.

FISSION GAS RELEASE FROM FUELSDURING IRRADIATION

A study is being made of the release of fission gases fromirradiated fuels, which could prove to be a convenient andimportant way of characterising the behaviour of such fuelsin service.

Preliminary design investigations showed that a Chouca rigis unsuitable for conversion into the "flow capsule" facilitynecessary for studying the complex mechanisms controllingthe release of fission gas from ceramic fuels. Investigationof other commercially available irradiation facilities showedthe French HF5 rig to be the best choice.

In support of the main programme, apparatus was con-structed to obtain data for the design of charcoal delay bedsassociated with the rig, and to measure the.surface area ofsmall samples of densely sintered nuclear fiiels using an "Kr-traced krypton adsorption technique.

A computer programme was written for evaluating a gene-ralised concentration function for the diffusion r lease offission products from fuel material in the form of thin plates.Curves were plotted for the complete range of fission productspecies likely to be of interest.

ADVANCED FUELSA scientist who had spent a period of training in Germany

made a 'our of nuclear research centres in Europe to investi-gate trends in advanced fast reactor fuel research. A researchprogramme for the Board in this relatively new and undevel-oped fleld was launched, and work on modified carbide fuels(e.g. UCS, UCN, etc.) was initiated. A glove-box line is beingfabricated for the practical implementation of the programme.

COMPATIBILITY STUDIESAt the end of the first quarter a scientist of the Physical

Metallurgy Division returned from a period of overseastraining at Karlsruhe in Germany. During this period heworked on the compatibility of UC with cladding materials,and published six papers. One of the papers reports a noveltechnique by means of which interaction was shown betweenthe UC and the cladding material at temperatures whereconventional techniques showed no interaction.

STABILISATION OF URANIUM CARBIDE(UC) BY ADDITIONS OF URANIUM MONO-SULPHIDE (US), URANIUM MONOPHOS-PHIDE (UP) AND MOLYBDENUM (Mo)

As part of this programme the system UC2-UP was studied,and it was shown that these two components form a com-plete series of solid solutions. However, traces of U02 in theUP led to the production of some UC by the reaction

3 UC2 + UO2 = 4UC + COAttempts are now being made to prepare UP free of

oxygen in order to obtain more reliable data regarding thissystem.

In view of the present emphasis on the cost of nuclearftiels, methods of preparing UC-US solid solutions morecheaply than by sintering the two components together arebeing sought. Promising results were obtained by preparingUC-U mixtures by the carbothermic reduction of UO2 withinsufficient carbon to assure complete conversion to UC. Thishypostoichiometric UC, as it is called, is then reacted withzinc sulphide when the free uranium metal is converted touranium sulphide (US) and the zinc driven off. On furtherheating solid solution of the VC and US takes place"! Themethod should be applicable to UC-UP solid solutions.

Additions of molybdenum were shown to prevent UÇ,formation in carbide fuels. It is desirable that the metalshould be very finely divided, and coating of the individualfuel grains with molybdenum by deposition from decom-posing molybdenum hexacarbonyl Mo(CO), is being tried.

A neutron radiograph ('ƒ tile cVu'wai-/' r/</ \ho\viihi the pitrtnil tneluUm-n ojthe uranium spheres in one ot the ùipsules. The dunitiiie ean be urn in themtittle.

URANIUM PHOSPHATESA gravimetric method for the determination of uranium

(VI) and phosphate in acid solutions was thoroughly investi-gated. Particular attention was given to the phosphateanalyses because they must be carried out in the presenceof an excess of uranium, as a result of which contaminationwith ADU, among others, is possible. Witli a view to ensuringaccurate results, the limiting values of the different speciesin the solutions were determined, and a list was compiledof the different products which can be analysed using thismethod.

Uranyl phosphate studies, with the emphasis on decompo-sitions and solid state reactions in the range 1 000°C to1 600°C were continued. Uranium(IV) phosphates and thethermal behaviour of different mixtures of uranyl nitratephosphoric acid were also studied. These studies indicatedthat only the UP ratio of the original product or mixturewill determine the final product under particular conditions.

Tests are at present being conducted on the quadruple massspectrometer to determine the effects of different variableson the peak height.

ANALYTICAL METHODSANALYSIS OF URANIUM

This work is being undertaken by the Board, working inclose collaboration with the National Institute for Metal-lurgy.

A method was deveJoped for the determination of bothacid-soluble and acid-insoluble uranium in ores. This methoduses PADAP reagent and has a lower limit of detection thanthat of previous methods-2 ppm of U3O, as compared with20 ppm of U,Ot.

A manual of methods for the determination of trace im-purities in refined uranium oxides and uranium fluoridesis being compiled in collaboration with NUFCOR and shouldbe ready for publication in the near future.

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ACTIVATION ANALYSISNeutron activation analysis offers many interesting and

useful applications in a wide variety of analytical techniques.The Board has, for some years, been investigating some ofthese techniques with a view to local application.

During the past year these activities increased to such anextent that the responsibility for the general analyticalaspects of the technique was allocated to one group only.It includes a large number of research and developmentprojects as well as the routine analyses undertaken on contract.A second group is responsible for the chemical separationaspects of the work while a geochemist was recently ap-pointed for all the geochemical aspects of geological studies.

Institutions with which the Board co-operates at present orwill shortly co-operate, include the following:

Dental Research Unit, University of the Witwatersrand.Medical Research Council.Zoology Division, University of the Witwatersrand.Geology Division, University of Pretoria.Department of Water Affairs.National Institute for Metallurgy.Criminal Bureau, South African Police.Certain mining groups.

Work on the following projects is in progress:(i) the determination of trace elements in granite systems

for the geochemical study of granite bodies;(ii) the study of copper deposits for characterising the

formation of copper mineralisations;(iii) the study of uranium deposits by means of water

analysis;(iv) the study of mineralisations in general by means of

water analysis;<v) hair identification and pattern residue tracing in

forensic investigations;(vi) the study of trace element compositions of teeth and

mineralised tissues for investigations after dentaldecay and calculus formation;

<vii) the study of trace element differences in certainhuman tissues for correlations with certain illnesses;

(viii) the study of the copper content of locusts as relatedto their migration instinct;

(ix) the analysis of precious metals in a variety of samples.The necessity of chemical separations for certain deter-

minations is still realised and determined efforts are beingmade to implement a number of developed procedures. Inaddition, a chromatographic separation procedure developed

for the precious metals will shortly be applied to ordinary oreand matte. An apparatus for the automatic separation ofelements, especially in biological samples, is nearing com-pletion. Group separation schemes for geological samplesare at present being investigated.

A second y-spectrometer was delivered during the yearand put into service. Both systems were supplied with mag-netic tape units, and processing of the y-spectrometric datais progressing satisfactorily.

The standardisation programme was extended and atten-tion is at present being given to epithermic activationanalysis and flux distributions in the different irradiationpositions.

MASS SPECTROMETRYISOTOPIC ANALYSIS

A knowledge of the isotopic ratio of certain elements isoften of vital importance. Mass spectrometry is used atPelindaba as a convenient and very precise means of deter-mining these ratios and many routine analyses were carriedout, including 34 uranium analyses.

The development of a suitable method for the analysis oflead isotopes was continued and a total of 97 analyses werecarried out. A method developed at the National Bureau ofStandards (U.S.A.), in which silica gel is added to the leadon the filament, has been found to hold promise. Experimentsalso indicate that both ion intensity and precision areimproved by increasing the sample size.

A new triple-filament mass spectrometer for surfaceionization analysis was installed. Good results, with veryhigh precision, were obtained on uranium isotopic standards.

TRACE ANALYSISOf various multi-element techniques for the survey analysis

of solids, spark-source mass spectrography offers the greatestscope and sensitivity. With the instrument acquired by theBoard in 1970, it is possible to cover the mass range fromlithium to uranium on a single photographic plate with adetection limit of 0,1 ppm and an analytical precision of lessthan 5% relative standard deviation.

Preliminary studies were concerned with optimising thetechniques for quantitative analysis, with particular attentionto sample preparation, data processing and factors affectingreproducibility. In addition, a start was made on the analysisof air pollution particulates.

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T

This' tri/k filament mass spectrometer was installed and renders highprecision results.

ECONOMIC STUDIESA computer programme, PELINOMIC II, has been deve-

loped for evaluating the cost of electricity produced bycurrent power reactor types. It is hoped that this programmewill be of some use to ESCOM when they commence theevaluation of the tenders for Koeberg A power station, sometime in the near future.

The third report by the Nuclear Power Committee of theAtomic Energy Board, which briefly reviews the projectedeconomics of advanced reactor systems being developed invarious countries overseas, was published. Work on thefourth report in this series, which is concerned with thelong-term study of the South African electricity generatingsystem, is well advanced.

Work has also started on the production of a "middle-term" economic planning model which ESCOM will requireas an aid to management decisions in the near future. Thisproject is being undertaken by a joint AEB-ESCOM team.

REACTOR DEVELOPMENTThe Board's work on thermal reactor systems has now been

completed, and a long-term project on the reactor physicsof fast reactor systems has been initiated. This is of importancebecause of the probable introduction of fast breeder reactorsinto the South African electrical generating system in thefuture. Attention is at present being devoted mainly to thedevelopment of computer programmes.

THEORETICAL CALCULATIONSThe one-dimensional computer programmes PELSN-I and

PELX-1 are fully developed at present and furnish satisfactoryresults in the analysis of simple fast assemblies. Attention isat present being given to the development of time-dependentand multi-dimensional neutron transport programmes and toan existing Monte Carlo computer programme.

Evaluated neutron point cross-sections over the energyrange 0,001 eV to 15 MeV were compiled in the form of tablesand magnetic tapes for uranium and transuranium isotopesand for the elements in materials used for fast reactor con-struction. These data are at present being prepared as inputdata for the computer programme XSECTN developed locallyto calculate fast neutron spectra and weighted neutron groupcross-sections for later applications in a super code whichwill in due course be developed for the complete evaluationof fast reactor systems.

SODIUM STUDIESSodium is the preferred coolant for fast breeder reactors.

In view of the potential importance of such reactors in ftiturepower programmes, and in the light of experience with thePELINDUNA project, the Board is pursuing certain sodiumstudies, particularly the behaviour of fuels and componentsin the presence of liquid sodium.

SODIUM MASS TRANSFERThe transfer of fission products in the sodium coolant is an

important safety consideration, and the Board is continuingits studies in this field.

Work on uranium-fissium alloy development was aban-doned when it was found to be impracticable to fabricatespheres from this alloy. Instead the fabrication of sinteredUO2 pellets containing fission product oxides is being under-taken. These pellets will be expr to the sodium in the loopin the form of artificially defectea .el pins, making the masstransfer results more directly applicable to sodium-cooledfast reactors. The necessary holder to support these fuel pinsin the loop has already been designed and manufactured onthe basis of water flow tests in a mock-up.

SODIUM CORROSIONCorrosion tests on the zirconium alloy 3ZI were continued.

Results indicate that there is not only a critical temperaturerange in which the alloy is catastrophically oxidised insodium, but also a critical oxygen concentration range.Tests to confirm these findings are proceeding.

COMPATIBILITY STUDIESThe Board is carrying out studies on the compatibility of

sodium with cladding and structural materials as well as withfuels. Some tests were completed, but no reliable conclusionscould be made since the provisional method of sodium fillinggave no control over the oxygen content of the sodium.

An apparatus for filling capsules with sodium of carefullycontrolled oxygen content was therefore designed and con-tracted. A new furnace was constructed to maintain com-patibility capsules at steady high temperatures over largeperiods, while the original furnace was redesigned andimproved.

THE DEVELOPMENT OF REACTORMATERIALS

DISPERSION-STRENGTHENEDZIRCONIUM ALLOYS

Zirconium is an important construction material used inwater-cooled reactors. These reactor types are likely to be inuse for several decades to come, and this provides the incen-tive for the Board's continuing programme lo developzirconium alloys with improved high-temperature properties.

Early in the year very high densities were obtained fromsintered zirconium samples. These samples, with densiiiesapproaching the theoretical value, also had good mechanicalproperties because improved handling methods resulted inlower oxygen contamination of the samples.

Installation of a hydrostatic press capable of pressures upto 400 N/mm2 greatly facilitated the fabrication of ZrH2-CaOcompacts for sintering.

Work was begun on a study of grain growth characteristicsof dispersion-strengthened zirconium alloys during sintering.The effect of dispersoids on the sintering process will beinvestigated. Samples were prepared with various CaO con-tents, and sintering at various temperatures foi differenttimes has begun.

A rotary swage which was installed will be used to preparesamples for recrystallisation studies, creep tests and hightemperature tensile tests.

MECHANICAL PROPERTIES OFREACTOR MATERIALS

No simple solution was found to the corrosion problem of3ZI zirconium alloy creep specimens. The only solutionappeared to be a continuously purified inert gas environmentfor the specimens, of which the high costs prompted a re-evaluation of the necessity of creep work on 3ZI, and a deci-sion to abandon further work on this alloy.

Instead it was decided to pay attention to the determinationof creep properties of the locally produced stainless steels toserve as reference for post-irradiation creep work on thesealloys. This work was hampered from the outset, however, byan inexplicable drift in the readings of the creep transducers.This problem has not yet been solved and is receiving furtherattention.

17

'

•er , T - . " ~ .•••

- ' v ^ i- - - ^ j> '

'fj ^

ft ;

ENVIRONMENTAL STUDIES ON THELAND AND IN THE SEA AROUNDDUINEFONTEIN

The purpose of this investigation is to determine inadvance what effect the operation of a number of nuclearreactors will have on the environment concerned.

Every environment has its own capacity for the amount ofradioactivity that it can safely absorb. This capacity dependson factors such as the ecology, its use by man as a source offood, recreation and housing; certain physical parameterssuch as natural dilution, dispersion and reconcentration bybiological forms.

All these different factors are being studied at present toobtain quantitative values used for the determination of safelimits for radioactive releases. During the past year, specialattention was devoted to the determination of reconcentrationfactors of biological life in the sea for both natural radioactivetracers and stable tracer elements. Extremely sensitive methodsfor the accurate observation of these very low levels of con-centration were developed.

, E*\mMM^»lsnuhH M pumtfMUmmckOetsJricrmAreTSim stulits. \

PEACEFUL APPLICATIONS OFNUCLEAR EXPLOSIONS

Developments overseas have shown that there are manypotential peaceful applications for nuclear explosions. Theseinclude, among others, the excavation of harbours .nulchannels, the stimulation of gas and oil flow in undergroundreserves and the exploitation of low-grade ores by fracturingand in-situ leaching. With a view to the possible use of someof the techniques in South Africa, the Board is investigatingsome of the basic aspects of peaceful nuclear explosions.

The mechanism of crater formation was investigated hymeans of model experiments with crater explosions. A testingsite for the execution of such experiments was prepared and anumber of crater explosions was carried oui in undisturbedearth. The high cohesion of the earth caused inefficientcrater formation, and variations in moisture content andmechanical properties were responsible for unreliable results.Different techniques were used for plugging the placementholes and it is clear that the efficiency of the plugging has aconsiderable influence on the mechanism of crater formation.A sandpit was therefore prepared in which crater explosionsare now carried out. These explosions will therefore becarried out in a homogeneous material with low cohesionwhich can be used for the efficient plugging of the placementhole.

Attention was also given to methods for predicting damagecaused to buildings and structures by seismic waves, sinceseismic damage is one of the most important restricting factorsin the use of confined explosions. With the aid of predictionsof response spectra of seismic waves for various explosionconditions, estimates were compiled of the cost of seismicdamage as a function of distance and population of towns andcities as well as of population densities of rural areas. Theseestimais show how the economy of scale of nuclear explosivesis influenced by seismic damage for a given allowable damage.The urban and rural population distribution, together withthe estimates of seismic damage, were used to evaluate theapplication possibilities in this country.

Information is being collected on the strength and theyielding properties of rock as well as on its equation of state.A programme was commenced in which published data willbe supplemented by laboratory tests.

APPLICATION OFRADIO-ISOTOPES

AND RADIATION

edical, agricultural and researchè

Institute for Metallurgy, the mining industrycmd other industries and organisations.

8OLUTION8of uranium

i was built for the measurementin Purlex-plant solutions, and trials were sncce«fulrf completed at onep f p

>of me uranfenn mines. The succes» of this instrmnert should proride a means for tke control ofPurkx plants for optimom operation. An automatic-control theoiy #a» developed »rh«t the bestmeasurement and control points in nnibistage systems can be dccMed On. Rwere done at sereri difiercrit Purlex jjUnts; and th^c o i t f i o l p o i i c y i s i m p l e m e n t e d . ' : ' . ' : ; '" ;' '\-*~. '-'•_ .["• '\:~ ~'~\ •'•'.•-••..'••.' .,.-- '";--

LONG-TERM PROJECTSCyanide gauge

A nuclear method for the continuous measurement of theconcentration of sodium cyanide in gold mine extraction plantsolutions was developed. Following laboratory tests a trialinstrument was installed on a typical mine and the resultsobtained appear promising, although problems arose with theaccurate analysis of the plant solution containing foreignmaterial. The temperature sensitivity uf the instrument re-mains to be tested, as well as its operation in a coarse slurry.

Particle size analyserAn elutriating column, capable of a comparatively sharp

separation of a slurry material into under and oversize wasconstructed. Using nuclear density gauges, it is then possibleto obtain a measure of the size distribution of the solid par-ticles in the slurry. Final testing of the method on continuousfeed material awaits the construction of a slurry-handlingsystem.

A second method of continuous particle-size monitoring,based on sedimentation techniques, will also be examinedwhen this system is constructed.

Radiolsotope X-ray fluorlmetryThe development work on a method for the determination

of the uranium content of ore was completed and published.A mining group is now interested in using the method intheir laboratories and plants. A copper analyser for the con-tinuous analysis of copper residue in copper reclamationplants is under investigation. It should be possible to makegood use of this analyser for the automatic control of reclama-tion processes.

Various other test rigs were also built during the year. Itwas, among other things, proved that the inactive iodineload of thyroid glands can also be determined with the aid ofradioisotope X-ray fluorimetry.

Mixing of powders in silosThis basic study to analyse and report on the flow and

mixing of fine powders in containers and silos, is beingcontinued. A theoretical model describing the flow of powdersunder gravitation was set up and is being tested with the aidof the tracer results obtained earlier.

Characterisation of Underground Water bymeans of Trace Element Analysis

The use of synthetic radioactive tracers to follow under-ground water has limitations because of the volumes and theproblem of obtaining homogeneous mixing. An investigationis being conducted in collaboration with the Department ofWater Affairs on the possibility of using natural tracerelements in a water body to distinguish it from other bodies.

If tracer elements are characteristic of a specific waterbody, it will be possible to distinguish clearly betweendifferent water sources with the aid of neutron activationtechniques. Knowledge of such differences is of primaryimportance in hydrology.

SHORT-TERM PROJECTSA large number of interesting short-term projects was

carried out during the year.The underground ventilation of a mine was measured by

using a radioactive gas, krypton-85. When studying problemsrelated to large quantities of ventilation air, as it is generallythe case in mines, the air flow can be effectively studied byreleasing radioactive gases in it.

The operation of a large ball mill was studied by means or2 kg of gold ore irradiated in the reactor. The retention timeof the particles in the mill was measured. It was found thatparticles with different sizes had different retention timesin the mill. These results shed considerable light on themilling process which had been approached empirically up tothe present time.

At the request of a mining group, investigations were con-ducted into the possibility of developing an ore/waste detector.The detector should sound a warning when gold ore is acci-dentally loaded on the waste conveyor belt. Tests conductedshowed promising results and a prototype instrument is beingbuilt.

A density gauge, based on the absorption of gamma raysand developed by one of the mining groups, was tested in thelaboratory to determine whether it would be suitable foruse in mines and whether its accuracy conforms to theprescribed specifications.

NATURAL ISOTOPES AND TRACERSDetermination of evaporation from earth surfaces

Two experiments were conducted at the HorticulturalResearch Institute to determine whether the labelled-layermethod for the determination of evaporation can also be usedin drier climates. There are indications that it can be used,but no definite deductions were made.

Underground flow of water In irrigated landAn experiment to determine the direction and rate of the

underground water flow was carried out in collaborationwith the Soil and Irrigation Research Institute at the PongolaIrrigation Settlement. Plants which become waterlogged andsoil which becomes brackish create a serious problem on someparts of the settlement. It appeared that the tracer used,namely "Cr, was not the most suitable as it was to a largeextent retained by the clayey soil. Laboratory experiments areat present in progress to find more suitable tracers forparticular types of soil.

Determination of the total volume of body waterof animals

The Cattle and Dairy Science Research Institute is con-ducting an extensive programme to determine the totalvolume of body water of certain farm animals at differentages. This knowledge is important for compiling the mosteconomical feeding programme. The method followed is thatthe animal is injected with a quantity of tritium and asample of the blood is taken at a later stage. Water is distilledfrom the blood and the water is then analysed by the AtomicEnergy Board for tritium.

The measurement of deuterium by means of agamma Isotope source

Deuterium is very useful as a tracer in small-scale experi-ments where water movements, etc. are investigated. For thispurpose a cheap rig was successfully erected in the laboratory.In this rig the deuterium nuclei are bombarded with high-energy gamma rays and the released neutrons are thencounted. At the present stage the rig is such that the deuteriumin natural water gives a count rate which is 200 counts perminute above the background rate.

Efficiency of drip irrigationThe efficiency of a drip irrigation system is at present

being investigated in collaboration with the HorticulturalResearch Institute. Tritium tracers are used to determinethe surface area and depth of the soil which can be servedby a single drip hole for different types of soil and under localconditions.

21

NuclidesNumber of

consignmentsActivity

mCi

ISOTOPE PRODUCTIONLOCAL MANUFACTURE

Where economically justifiable, the Board intends to pro-duce as many radioisotopes as facilities permit, and with thisin view, has embarked on a moderate expansion programme.

It was decided to install special hot cells for the productionof cobalt-60 and indium sources. Much of the manufacturewill be local and design work was started during the year.

The shielded glove boxes as well as all production equip-ment were transferred to the new Isotope Production Roomsin the East of the Reactor Building and these are at presentbeing used for the production of various isotopes.

Experiments are being performed to increase the effective-ness of I31I and Tc-99m generator manufacture. The " ' Iproduction apparatus was completed, but initial operationshowed that modifications would be necessary. The Tc-99mgenerators were tested by the Karl Bremer Hospital and regu-lar production should commence shortly.

Indium-192 production will start when modifications tothe welding machine are completed. An automatic pipettewas delivered and installed in the shielded processing cell.

Isotope production in SAFARI-1 for outside organisationsduring 1971 is summarised in the following table:

Argon-41Bromine-82CaIcium-45Chromium-51Cobalt-60Copper-64Germanium-77Gold-198Hafnium-] 81lodine-131Indium-192Iron-59Lanthanum-140Molybdenum-99Nickel-65Palladium-109Platinum-197Potassium-42Ruthenium-103Sodium-24Silicon-31Silver-110Thallium-204Zinc-65

50626

4.7I

501426312141

673

294

312

4 300,0465,0107,0

5 852,030,081,0

5,09 070,0

4,08 000,0

506,041,5

750,0646.0

16,31,0

18,0116,5

3,013 085,06 254,0

7,21,00,2

224 49 359,7

22

APPLIED RADIATION CHEMISTRYThe investigation of a number of radiation-induced syn-

theses with a view to commercial exploitation was continued.These included the polymerisation of ethylene, manufactureof wood plastic composites and various co-polymer syntheses.

ETHYLENE POLYMERISATIONThe gas-phase polymerisation studies were completed, and

results are summarised as follows:(i) The polymerisation rate is proportional to pressure to the

2,7 power and intensity to the 0,44 power;(ii) the reaction exhibits an activation energy of 0.2 kcal/mole

up to 100°C, and of 10,2 kcal/mole between 100 and 175°C.The polymer formed under the various conditions was

characterised in terms of molecular weight, infrared spectrum,density and crystalline melting point.

Studies of polymerisation in solution were commencedusing ethylenc solutions in heptane. At 50 bar the polymeryield is doubled in solution, but as the pressure is increasedthe rate in the gas phase increases rapidly, whereas the ratein the liquid phase remains essentially constant. The poly-merisation rate in solution was found to depend on intensityto the 0,4 power. The liquid-phase product exhibits an inter-mediate density (0,94 — 0,95), but shows unusually highmethyl content and unsaturation. The reason probably liesin the much lower molecular weights obtained, (4x«0*>, ascompared with values obtained in the gas-phase studies,(2x10s).

A vrood-pbatk floor for demonstration purposes showed visitors to thettdiatim Tedmthgy BuiU'mg some of the advantages of radiation inducedpttytnertsatton.

WOOD-PLASTICSComplete polymerisation data were obtained lor the poly-

ester-styrene mixtures and an acetone extraction method wasdeveloped to determine the degree of polymerisation.

Preliminary tests wvrc conducted lo determine improve-ments in the characteristics of wood-plastics.

Substantial improvements were obtained with regard tohardness, bending strength, abrasion resistance1 and com-pression strength. The water uptake was also considerablyreduced, but it did not bring about an improvement in thedimensional stability. Wood-plastics are also not weatherproofwithout an additional surface coating.

THE RADIATION-INDUCED CO-POLYMERI-SATION OF CHLOROTRIFLUOROETHYLENEWITH ETHYL VINYL ETHER

The radiation-induced co-polymerisation of chlorolri-fluorocthylene with ethyl vinyl ether was investigated in theliquid phase at 2CPC and — 7S°C over a »vide range of monomercompositions. A co-polymer was obtained in which the mono-mers alternate with nearly perfect regularity along the |H>IV-

23

mer chain over the entire range of monomer compositionsinvestigated. Both the rate of co-polymerisation and themolecular weight of the resulting co-polymer were found todepend strongly on the initial monomer composition-bothreaching a maximum value at an equimolar concentration ofmonomers. The monomer reactivity ratios were determinedand compared with calculated values for the system basedon the co-polymerisation parameters of the two monomers.It was found that a decrease in the irradiation temperaturewas accompanied by a marked decrease in the rate of co-polymerisation and the molecular weight of the co-polymer.

IRRADIATION SERVICESThe installation of the package irradiation facility com-

menced early in July and culminated in a continuous forty-eight hour monitored test run at maximum speed. The radio-active source of 50 000 curies of cobalt-60 was loaded andthe final acceptance documents signed.

This plant is intended for the sterilisation by irradiationof packaged products and the Board now offers a routineservice to manufacturers of, for example, disposable medicalequipment.

Preliminary dosimetry was carried out using dummy boxesloaded to give a mean density of 0,1 g/cm* and on the strengthof these results the first production run was started. To datethe products sterilised in the plant have been either rubbersurgical gloves or surgical sutures. The dosimetry resultsgathered so far indicate that the maximum throughput withthe present cobalt loading should be 6 400 kilograms/week

for a dose of 2,5 megarads. At present the plant is beingoperated on a 110 hour per week cycle but this is expected toincrease to continuous operation as new contracts are finalised.

Extensive dosimetry was undertaken to determine theoverdose ratios on product boxes. Several product geometrieswere tried to limit the overdose ratio on the surgical sutures(which are sensitive to radiation damage on overdose), anda maximum overdose ratio of 1,17 was achieved on a box of24,8 kilograms. This figure is well within the specificationacceptable to the customer.

The production of wood-plastic material in sufficientquantities for manufacturers to assess its properties undercommercial conditions is also to be undertaken in this plant.Other products of radiation-induced reactions are underinvestigation in a study sponsored by a commercial firm andmay also be manufactured in the facility in trial quantities.

REGULATORY CONTROLThe number of authorised users of radioactive material

again increased gradually during the past year. Routineinspection visits were paid to all the users in the followingareas: Eastern and Western Transvaal, the Vaal Triangle, theWitwatersrand and Pretoria as well as in South-West Africa.Safety in connection with the use of radioactive materialswas found to be satisfactory.

USERS OF RADIOACTIVE MATERIALNON-MEDICAL USERS

The number of non-medical users on 31st December, 1971,was as follows:Industries 189Scientific and educational institutions 54Government departments 7Local authorities 14Total 264

These figures do not include the exempted use of antistaticbrushes, smoke detectors and luminous signs. These users arespread as follows over the Republic and South-West Africa :Johannesburg 38Pretoria 27Rand and Vaal Triangle 42Rest of Transvaal 37Natal 33Orange Free State 19Eastern Cape Province 8Western Cape Province 37Rest of Cape Province 12South-West Africa 11Total 264

MEDICAL USERSThe medical use of radioactive material up to 31st

December, 1971, was as follows:Hospitals where radioisotopes and radiation wereadministered to patients 12Hospitals having a general authority to useradioactive material 6Number of cobalt-60 teletherapy sources athospitals 9Cobalt-60 teletherapy sources used by radiotherapistsin private practice 2Medical practitioners in private practice authorisedto use radioactive material 16Pathological laboratories authorised to useradioactive material for in vitro tests 2Medical research institutes authorised to useradioactive material 2

COURSESThe Board has again, as in the past, rendered assistance to

educational institutions with the presentation of the followingcourses to promote a wider knowledge of the use of radio-active material as well as safety in its use.1. Specialised course in industrial radiography and other

non-destructive test techniques - the Pretoria College forAdvanced Technical Education during June 1971 and againduring November 1971.

2. Holiday course for teachers - the Pretoria Teachers'Training College during July 1971.

3. Health Physics. A summer school by the S.A. Associationof Physicists in Medicine and Biology, 1-2 March 1971, atPelindaba.

4. Introductory course on the Use of Radioisotopes, 26-30July 1971, UOFS.

IMPORTSThe following quantities of radioisotopes were imported

by private undertakings under the Board's authority during1971:

Activity in mCiAmericium-241 737,306Americium-24 I/Beryllium 630,000Barium-133 0.003Caesium-134 1,000Caesium-137 56 900,505Calcium-45 64,100Calcium-47 4,175Carbon-14 1 005,508Cerium-141 6,000Cerium-144 12,000Chlorine-36 0,050Chromium-51 283,500Cobalt-56 1,000Cobalt-57 23.880Cobalt-58 0.020Cobalt-60 110 164 157,025Gallium-67 310.000Gold-195 5,000Gold-198 1 788,000Hydrogen-3 67 079,264Indium-llîm 174,000Iodine-125 1 187,690Iodine-131 21083.916Iridium-114 2,000Iridium-192 459 902,000tron-59 38.801Krypton-85 5 571,300Lead-210 0,050Mercury-197 157,000Mercury 203 113,000Phosphurus-32 3 308,450Plutonium-238 180,000Polonium-210 1808,000Promethium-147 5 005,000Promethium-I47/Aluminium 1000,000Radium-226 0,018Rubidium-86 35,000Selenium-75 26,250Sodium-22 4,500Strontium-85 24,500Strontium-87 222,000Strontium-87m 320,000Strontium-90 395,105Strontium-90/Yttrium-90 20,000SuIphur-35 43,005Technetium-99m 49 353,020ThaIlium-204 80,000Thulium-170 10,000Xenon-133 6 248,550Ytterbium-169 1,000Zinc-65 1,500

Total H0 849223,988mCi

or 110 849,224 Ci

2S

During 1971, the Board imported the following quantitiesof radioisotopes on behalf of medical users and industrial andresearch institutions:

Americium-241Caesium-137 .Carbon-14 . .Cerium-141 . .Chromium-51Cobalt-60 . . .Europium-152Gadolinium-153Gold-198 . . .Hafnium-] 81 .Iodine-125 . .Iodine-131 . .Iridium-192 . .Iron-55Krypton-85 . . .Mercury-197 . .Mercury-203 . .Niobium-95 . .Osmium-185 . .Phosphorus-32 .PIutonium-238 .Promethium-147

Medical Research Industries— 45 —

39,45

5

653

3716 578

320

1016

115.405

222

269

17316 505

231030

120155

1230,1

4000

200

2

140 000

1 8 0 0220

Medical Research IndustriesRuthenium-103 . . — 12 —Ruthenium-106 . . — 1 —Strontium-85 . . . . 1 — —Tantalum-182 . . . 2 65 —Terbium-160 . . . . — 5 —Tritium — 5 400 —UridineH,<G) . . . 6 83 —Zinc-65 — 16 —

TotaJ 17 667,45 157 716,50 142 222

Grand total . . . . 317605,95 mCi or 317 606 Ci

53 809 097,004 mCi53 809,097 Ci

111 166 829,938 mCi111 166,830 Ci

Total imports into South Africaduring 1970

orTotal imports into South Africaduring 1971

or

EXPORTSThe following radionuclides, produced in the cyclotron of

the Council for Scientific and Industrial Research, wereexported:beryllium-7, cadmium-109, cerium-139, sodium-22,strontium-85.Total approximately 1525 mCl.

TABLE 1: BETA-GAMMA EXPOSURE: 1971

28

TABLE 2: NEUTRON EXPOSURE: 1971

(N.B. No neutron badges were issued to NIM during 1971 )

TABLE 3: URINE ANALYSES FOR URANIUM: 1971

Uranium concentrations in /ig/\

27

ROUTINE MEDICALEXAMINATIONS

During the year, 581 newly appointed members of staffand 65 who resigned were medically examined, and 504were re-examined.

A total of 889 chest X-ray photographs were taken and607 total blood-cell counts carried out.

RADIATION PROTECTION ANDCONTROL

PERSONNEL DOSIMETRYRadiation Workers were re-classified into Class A and

Class B radiation workers during the year. Beta-gamma andneutron film badges supplied by the radiation control serviceof the SABS were issued on a routine basis to all class Aradiation workers. Film badges were supplied to class Bradiation workers only when required. Tables 1 and 2 givethe dose equivalent received by staff as recorded by the filmbadges. Table 3 gives the urine analysis results for uraniumas performed by the Chamber of Mines Safety laboratory.

The equipment for thermoluminescent dosimetry was putinto full use and all class B radiation workers were issuedwith thermoluminescent dosimeters. These dosimeters areread out on a routine basis, or when required. The equipmentwas also used on a number of occasions to measure exposurerates in special circumstances.

Class A radiation workers as well as other members of thestaff were counted on the whole-body counter. No cases ofcontamination occurred where further action was required.

PROTECTION ON THE SITERoutine health-physics services were provided throughout

the year. There was a further increase in the use of dualphosphor detectors for the determination of alpha and betacontamination. The automatic sample changer with associatedcounting equipment was put into operation, and is beingused for the processing of routine samples for the entire site.In a few instances activation products suspended in the'reactor pool occasionally gave rise to exposure rates of up to15 mR/h at the surface of the pool water, but staff exposuresremained low.

When a penetration plug was removed from the bottomplug of the reactor, surface contamination activity in thesub-pile room went up to l/iCi/cm* and airborne activity upto IC/iCi/cm1; both for "'•Pu alpha activity. Subsequentcontamination into the containment and white areas of theReactor Building was brought under control after suspensionof normal work in the building for two days.

Although various articles with high radiation and con-tamination levels were decontaminated in the Waste DisposalBuilding, no person was exposed to more than 20 mrem perday. A continuous air monitoring system is at present beingbuilt to assist with the routine control.

In the Chemistry Building, ozone concentrations in thecobalt-60 cell at certain times reached levels in the regionof maximum permissible levels. This was due to failure of thecell ventilation equipment, and after the fault was rectifiedair sampling showed no measurable levels of ozone.

The active bays at the National Institute for Metallurgywere decontaminated in preparation for non-active work.Ultimately parts of the bays could be declassified, and thecontrol measures changed accordingly. Advice was given onthe lay-out and planning of the new NIM site, as well as onthe disposal of radioactive'waste.

A new type of decontamination mat was introduced at thehot wing exit of the Physical Metallurgy Building, and the

use of overshoes in this area as .. :-ontinued. The .natproved effective in con'uung tin- contan na.ior. to ihehot wing.

RADIOACTIVITY

ENVIRONMENTAL STUDIES / PELINDABAAREA

A more limited, but more purposeful monitoring pro-gramme was carried out to study the radioactivity in thevicinity of the National Nuclear Research Centre. The pur-pose was to keep a strict watch on the paths of exposurewhich could first lead to possible detrimental effects. Thecritical path, in the case of the Crocodile River, is via the con-sumption of fish. Routine monitoring of a variety of fishfrom the river and the Harrbeespoort dam revealed no in-crease in the normal background. In the case of the atmos-pher» the expected critical path of exposure is through milkintake. As in the past, the intensive monitoring of milk overa wide area around Pelindaba did not indicate any changein the radioactivity above the normal background.

Stricter control was exercised to determine precisely whatradionudides are concerned in waste releases to facilitatethe tracing of concentration effects in the biosphere inthis manner.

NUCLEAR BOMB FALLOUTFive nuclear bomb tests conducted by France in the

Southern Pacific Ocean resulted in the highest concentrationof short half-life fission products observed to date. Thesehigh intensity pulses were of short duration ani! the con-centrations were less than 0,1% of the permissible air con-centrations. Nuclear bomb fallout forms a unique tracer forcollecting information on a variety of ecological, biologicaland meteorological systems. A study was made of the particlesize distribution of these tracers as well as of the averageretention time in the troposphere, the ratio between air andfallout concentration, the ratio between the air and somefood chain concentrations (e.g. milk) and the pattern in thegeographical distribution of the air concentrations.

SAFETY

GENERALThe promotion of safety was extended in the past year.

A Building Safety Committee was established at the TechnicalServices Building and permanent safety officers were placedin the building. This has aroused a positive interest in Safetyin the divisions housed in the Technical Services Building.The new Emergency Control Centre in the Main EntranceBuilding was occupied and put into operation.

TRAININGAn advanced Safety course was given by the National

Occupational Safety Association (NOSA) at Pelindaba. Itwas attended by 52 of the Board's supervisory staff, and allcompleted the course successfully.

A number of lectures and courses on Safety and First Aidwere given to other staff during the year.

CASUALTIESThe Frequency Rate for the AEB for the year 14>7I was

7,9. This shows a considerable improvement in the safetystandard as compared to previous years.

During the year 286 casualties were reported to the safetyofficers, of which 16 had to be reported to the Inspector oflabour because of their serious nature.

FUNDAMENTAL STUDIES

SUMMARYDespite lengthy delays due to maintenance of and im-

provements to the Van de Graaff accelerator, good progresswas made with the experimental research programme innuclear physics, especially with the use of the on-line com-puter. Studies of the inelastic scattering of fast neutronsfrom various elements were continued with the emphasis onthe investigation of gamma rays resulting from the inelasticscattering. The study of <p,n>, (p,y) and neutron capturereactions progressed well. Improvements were made to therig as well as to the instrumentation for the investigationof gamma spectra resulting from the capture of slow reactorneutrons. The lifetimes of nuclear states excited by neutroncapture were studied by means of a two-parameter system.The theoretical physics programme was actively pursued ona wide front. Operational research techniques applied to thelong-term planning of electricity supply were refined andnumerical methods were further developed.

In the field of chemistry research was, inter alia, conductedon the following: the -idiolysis of aliphatic alcohols, ionkinetics, research on liquid metal and molten salt as wellas the thermodynamic properties of molten sodium alloys.

The research programme on extraction metallurgy resultedin the development of electrochemical methods to expeditelaboratory studies of uranium leaching.

Further studies on irradiation damage were conducted inthe cryogenic irradiation facility. A scanning electronmicroscope was put into service during the year. Othermaterials investigations included neutron diffraction. X-raydiffraction, elastic and magnetic properties of uraniumcompounds and the transport and internal friction propertiesof irradiated metals.

In the medical field work was continued on the rejectionof transplanted organs. Other medical work included radio-active immuno-assays, primary liver cancer studies and thediagnostic use of radioisotopes.

Research on aerosol physics included investigations onfilter efficiency and work on the diffusion of gases wascontinued. The rig for the experimental study of the flow ofneutrons through conical tube orifices in water shields wascompleted.

NUCLEAR PHYSICSACCELERATOR OPERATION

Satisfactory performance was once more obtained fromthe Van de Graaff accelerator in spite of occasional problemswith the short life of the home-made ion sources and withthe accelerator cooling system. A new accelerator rube wasinstalled during January and improved the performance athigh energies considerably. The charging belt as well as thebearings in the drive motor and the generator had to bereplaced during September. Several modifications were madeto the vacuum system and preparatory work was done for theinstallation of a duoplasmatron ion source.

Good progress was made with systems programmes forthe on-line computer. The computer was used extensivelyfor data processing, as well as for simple on-line datacollection. The initial phase of a visual display system wasalso brought into operation.

SCATTERING OF FAST NEUTRONSA detailed investigation of the elastic and inelastic scat-

tering of fast neutrons from manganese was carried out.Considerable progress was also made with the study of gammarays produced by inelastic neutron scattering from severalnuclei. The research on gold, scandium, iodine, antimony andbromine was completed and published. Experimental work oncesium and rubidium was completed and measurements on

holmium were started. These studies provided valuable in-formation about the energy levels of stable nuclei.

(p,n) REACTIONSThe reaction *sTi(p,n,y)49V was investigated in order to

determine spins and electromagnetic mixing ratios for levelsin 49V. A number of gamma-ray angular distributions andneutron time-of-flight spectra were measured. The on-linecomputer was used for recording two-parameter data. Theresults are being compared with Hauser-Feschbach calcula-tions. The reaction "Getp.n.y^As is also being investigatedin order to determine the level structure of "As.

(p,Y) REACTIONSThis project, undertaken jointly by the Potchcfstroom

University for CHE and the Board, utilized about a quarterof the available accelerator running time. Excitation curvesbetween ! and 2 MeV were measured for the reactions2sMg<p,i')»Al, "Stp.yPCl and »CKp.x^Ar. The gammadecays of a large number of resonances were carefully investi-gated, spin assignments were made in many cases and tin-branching ratios for several bound states were determined.Several new energy leveis were discovered in the process.

NEUTRON CAPTURE REACTIONSThe apparatus, as well as the instrumentation for the

investigation of gamma spectra produced by slow reactorneutron capture, was further improved. The complexity ofthese spectra is reduced considerably by the use of a pairspectrometer but the efficiency of the system becomes verylow. Data obtained for the final nuclei 71Ge and MNi wereanalysed. Steps were taken to reduce the gamma backgroundat beam tube no. 1.

In the study of the lifetimes of excited nuclear states,produced by neutron capture, use was made of a two-para-meter system. The time delay between gamma rays in acascade can be measured as a function of gamma energy.Measurements were made on rhodium, silver, dysprosiumand lutecium.

THEORETICAL PHYSICSELEMENTARY PARTICLES

The properties of the exact non-perturbative solution of anon-linear fermion field equation of motion were deducedby two different and complementary methods. The conditionfor the existence of this solution could be related to aninvariance of the primitive field equation of motion throughthe role of a massless propagator in it. This solution has stronginteraction. The existence of a further solution with weakinteraction determines the coupling constant in the equationof motion. It appears possible to formulate isosymmetry.electromagnetism and weak interaction of the correct orderin a natural way in this theory.

Relativistic three-particle equations were deduced byfunctional techniques and could be written in terms of theunderlying two-particle dynamics. The two-particle scatteringequation leads to a partial solution of the three-particleintegral equation since its form permits Fredholm techniques.The convergence of the solution is improved by the presenceof multiple scattering effects. The inree-body theory wasapplied to radiative decays ofpseudoscalar and vector mesonstreated as unstable composite particles.

In the case of particles with spin \ which, in general,couple with other particles or external fields, a four current ofdensity and charge and the field energy could be formulatedin such a way that a rigorous physical interpretation in termsof positive probability and energy density was possible. Ageneral class of form factors required in this connection wasdeduced. The resulting non-locality of the density and current

31

in ordinary space-time was deduced for the case of spin = 0,as a function of. particle mass. The gauge invariance of thedensity and current for the case of spin \ particles withelectromagnetic interaction was discussed further.

THEORETICAL NUCLEAR PHYSICS MANY-BODY PROBLEMS AND SOLID STATETHEORY

Two of the theoretical research projects were concernedwith the role of isospin conservation in heavy nuclei. Experi-ence gained with experimental work on the tandem accele-rator of the Max Planck Institute in Heidelberg during a shortoverseas visit, led to the inclusion of isospin violatingcontributions to compound nucleus cross-sections. The trans-mission coefficients used in statistical model calculationscan be modified to include the characteristic analogueresonance behaviour. These changes were incorporated inPELINSCA, the scattering programme developed at Pelindaba.

The second investigation is a continuation of the many-body description of isospin. If electromagnetic interactionsare eliminated completely, isospin conservation is restoredby extending the single-particle description to include isospinpolarisation. The isospin polarisation approximation (IPA)is a generalisation of the random phase approximation (RPA).In the conventional RPA the appearance of zero frequencysolutions is always accompanied by the incompleteness ofthe set of eigenstates. By a deeper investigation into thedoubling of solutions within the framework of Green func-tions, it was possible, however, to show that the situation iscompletely different in the IPA. The eigenstates remaincomplete and the zero frequency solution is a real state.

The motion of a single nudeon in the nucleus was also thesubject of two projects. The first, carried out in collaborationwith a visiting physicist from West Germany, dealt with thedescription of single-particle states in a many-body systemwith interactions. Various definitions are used in theliterature but the one which agrees with what is interpretedempirically as single-particle or single-hole states, is in termsof the mass operator which occurs in single-particle Greenfunctions. When the spectrum of this operator is continuous,the single-particle state corresponds to a pole on the secondsheet of the complex plane. In the case of a discrete spectrumappropriate energy averages must be taken to isolate thesingle-particle behaviour. The latter case corresponds to thefragmentation of single-particle strengths among differentenergy states. The part of the mass operator which is off theenergy shell causes, apart from a width of the state, a non-orthogonality of the wave functions r,f different single-particle states. In terms of Landau's definition of single-particle energies in terms of functional derivatives of thetotal energy, this part of the mass operator is given byFeynman diagrams, where particle lines are cut.

Whereas this investigation concerned stationary states ofa single nucléon, the optical model provides a description ofscattering processes at arbitrary energy. By projecting themotion of a single particle out of the exact many-bodyequation of motion, it was possible to show that the opticalpotential is given by the mass operator. A simple modelcontaining all the elements of the formalism, is that of twoidentical fermions with mutual interaction and a commonpotential well. This model is being investigated to acquireinsight into the significance and the reliability of the common-ly used approximations to the mass operator.. .,

In the field of solid state physics a study is being made ofinteractions in antiferromagnetic crystals. An anomalousbehaviour of the speed of sound has been observed experi-mentally in the region of the Neél temperature. It is expectedthat the interactions mentioned above can be used to explain _,the corresponding behaviour of the elasticity constants.

NUMERICAL ANALYSISWork on the solution of long-term planning problems was

continued and the methods used were refined.

Indefinite quadrr'Jc programming problems and methodsfor their solution are being studied.

The study of the solution of inverse eigenvalue problemsusing optimization techniques was continued. A programmeis being developed for the solution of continuous Tscheby-scheff problems using a discretization process in which aseries of coupled linear and non-linear programming problemsare solved.

CHEMISTRYRADIATION CHEMISTRYRadiolysis of aliphatic alcohols

The general theory developed for the lower alcohols tocorrelate radiolysis' results with mass spectrometric datawas also applied to the butanols. The agreement between thedifferent sets of data was not as good as in the case of thelower alcohols. It became clear that reactions involvingcomplex structural rearrangements cannot take place in thecondensed phase. The results also indicated that the dis-sociation of excited molecules into molecular products andeven radical fragments becomes much more important in thelarger molecules where steric factors tend to outweigh thecage effect. These factors should therefore be taken intoaccount when attempts are made to correlate radiolysis andmass spectrometric data.

The Radiolysis of ethylene glycolIt was found that the product 2-methyl-l,3-dioxolane

formed in the radiplysis of ethylene glycol is in reality asecondary product resulting from a condensation reactionbetween the primary product, acetaldehyde and ethyleneglycol.

It was shown that the acetaldehyde is formed in a chainreaction leading to extraordinarily high yields (up to200000 molecules of product formed per lOOeV energyabsorbed). Hitherto, radiation-induced chain reactions in puresaturated compounds leading to yields of this order of magni-tude were unknown, making this finding of considerableacademic and even perhaps industrial interest.

Radlotytlc pyrofysls of alcoholsDuring the y-irradiation of isopropyl alcohol vapour, ether

is formed by a chain mechanism leading to very high yieldsat temperatures above 300°C. The yield (expressed as mole-cules formed per 100 eV energy absorbed) was 1 000 at350°C 0,13 atmosphere and a dose of4,8krad. The economicsof this process as a commercial means for the preparationof di-isopropylether was calculated. It was found that theprocess has commercial possibilities and justifies furtherinvestigation.

Radfofysfs of «thanol-«fhyi«n« solutionsThe following are the most important findings resulting

from the investigation into the radiolysis of ethanol-ethylenesolutions: - • - . . - .(a) existing conceptions of the radiolysis of pure ethanol are

. also applicable to the telomerisation of ethylene inethanol; ' •. .

(b) at low dose rates, but at high ethylene concentrations,telomerisation is replaced by polymerisation; •

(c) at room temperature the reaction rate constants respon-sible for the formation of telomers are smaller than those

i responsible for the growth of the chain. . -As a result of the above-mentioned conclusions a start was

made with the study of the telomerisation of ethylene inother alcohols. Results indicate that there is a big differencein the reactivity of the different aliphatic alcohols in telo-merisation réactions. A fundamental study on this aspect isbeing undertaken at present. - . ..

MASS SPECTROMETRYION KINETICS

The studies of the extent of energy randomization in thedecomposition of relatively small organic molecules byelectron impact were continued. The fragmentation of ethy-lene and its deuterated analogues C2HaD2 (trans) and C2HD3was investigated, using the retarding potential differencetechnique and the quasi-equilibrium theory of mass spectra.

Preliminary results indicate that hydrogen scramblingtakes place in ethylene before dissociation. Furthermore,isotope effects are observed to be very much greater in thecase of the metastable transitions than in the formation ofthe normal fragment ions.

Calculations within the framework of the quasi-equilibriumtheory are being carried out assuming different activatedcomplexes in order to explain these observations. Results todate suggest that it should not be necessary to invoke anyspecial decomposition mechanism to explain the normal massspectrum of ethylene. However, for the metastable transitionsnear threshold, it may be necessary to take into account pro-cesses such as tunnelling or predissociation to explain thelarge, isotope effects.

RESEARCH ON LIQUID METAL ANDMOLTEN SALTION SELECTIVE MEMBRANESIon exchange studies at high temperatures

The ion exchange process occurring when Pyrex powderis brought Into contact with the three systems NaCl + LiCI,NaCl + KC1 and KC1 + LiCI was investigated in the 3OO-575°Ctemperature range at intervals of 25°C. As a result of the highmelting points of the alkali chloride, ZnCl2 was used assolvent in all three cases. By applying the modified ion-exchange theory, the equilibrium constants were calculatedfrom the results for the ion exchange process as well as then-values and the n-type behaviour of the glass. Work on thefirst system was completed and satisfactory results wereobtained. In this manner it was, for example, confirmed thatPyrex is a two-phase glass consisting of a silica and a boron-silicate phase. Work on the second system is nearing com-pletion while that on the third has already reached anadvanced stage.

Initially it was thought that the influence of the solventon the ion-exchange process was so slight that it could beneglected. It was soon found, however, that this was not thecase and a complete set of experiments was carried out inwhich the ZnCl2 concentration was varied over the wholemole fraction range for the NaCl + Lid + Pyrex powdersystem. Extrapolation of these results to zero ZnC^ concen-tration furnished the activity constants of the pure binarymelt. As an addition to these results, a series of experimentswas also carried out with alkali nitrates, as it was possiblein this case to deal with pure binary melts.

Experiments with PbCl2 as solvent indicated that thesolvent itself also has an appreciable effect on the ion-exchange process.

Conduction phenomena bi ion-exchangemembranes

A basic investigation was commenced to study the natureand characteristics of ionic mobility in solid ion-exchangemembranes. Organic cation exchange membranes have beenused up to the present :

The mobility ratios for pairs of alkali metal ions as afunction of the membrane composition were determined fora series of relatively concentrated external solutions. Thesecharacteristics are at present being investigated in morediluted solutions. • " - ' . ' , . ' ' " ., Attention was also paid to the measurement of specific

conductivity and the possibility of electrochemically con-trolled ion exchange. These investigations are being continued.

Conditions have already been determined for the study ofionic flux ratios and mobility ratios in acetone media andthis work will be followed up by the experimental deter-mination of t ht se characteristics in the near future.

Modified Ion-exchange theoryBefore the validity of the Eisenman theory can be tested,

the main parameters, namely the thermodynamic equilibriumconstants, Ky, the ideality factor, n, and the ion mobility ratio,uj/uif must be determined for a particular system.

For the Pyrex(Na-Li)Cl system, uLi/uNa, Ky and n weredetermined while Kg and n were determined for a Pyrex(Na-Ii)NO3 system at different temperatures.

The dependency of "Li/u^a w a s investigated for differentexperimental conditions, namely temperature, applied voltageand zinc chloride concentration.

Emf measurements were done on Pyrex glass membranes sothat a comparison could be drawn with values obtained fromthe Eisenman equation. For the Pyrex(Na-Li)NO3 andPyrex(Na-K)-NO3 systems a satisfactory correlation wasfound between the experimental and theoretical values.

THERMODYNAMIC PROPERTIES OFTERNARY MOLTEN SODIUM ALLOYS

A detailed investigation, using emf measurements, of theternary systems Na-In-Hg and Na-In-Pb over their entirecomposition range was completed. A computer programmewas also written to handle the data used in calculating thevarious thermodynamic parameters.

USE OF ATOMIC ABSORPTIONSPECTROMETRY

Experimental measurements on the strongest lines ofcadmium, zinc and sodium were completed.

A theory was formulated to explain the decrease in theobserved cross-sections by taking the following factorsinto consideration:

(i) the effect of the natural broadening as well as theDoppler broadening of the final line profile;

(ii) self-absorption in the light source according to a simpli-fied two layer model;

(iii) differences in widths as a result of the difference intemperature of the sample and the effective temperatureof the radiating metal vapour in the source.

A computer programme was written for this purpose andit is possible to obtain a satisfactory fitting of the experimentaldata with the calculated corrections.

SALTING-OUT EFFECTS INTHIOCYANATE SYSTEMS

Various inorganic compounds were used to study theinfluence of different ionic species on the extraction behaviourof thiocyanic acid. These results were used in conjunctionwith the activity coefficients of thiocyanic acid in aqueousmediurr- obtained previously-to determine the salting-outeffects of different ions.

SPECTROSCOPE STUDIESThe spectra of cobalt, nickel - and iron in molten alkali

thiocyanate melts were determined. The spectral data wereused to elucidate the state of complexation of the metalsin the melt.

In addition, the spectra of RuUII), OstfH), RhUII), In(III) and Pd(II) thiocyanate complexes were measured inboth aqueous and fused thiocyanate media. The reductionof Ru(IlI) in molten thiocyanate was demonstrated spectro-photometrically. The reduction of IrilV), OstlV), Pd(IV).

and Os(IV) to the more stable lower oxidation state givenabove, was also observed in molten thiocyanate. At presenta theoretical interpretation of the above spectra is beingattempted.

SOLVENT EXTRACTION FROM MOLTENSALTS

Solvent extraction studies of metal ions from moltenthiucyanates into organic liquids were extended to includeall the group VIII as well as the group IB elements.

The results to date, using quaternary amines as extractants,have shown a large variation in the extractability of thevarious metal ions. The ions are extracted in the form ofanionic complexes.

The evaluation of the extraction mechanism is, however.

complicated by polymerisation and exchange reactions.Furthermore, the exact nature of the anionic species in themolten salt is not as yet known.

EFFECT OF ANIONS ON EXTRACTIONFROM MOLTEN SALT

It was observed that some anions caused a large decreasein extractions from molten thiocyanate. Attempts are beingmade to find the reasons for this decrease by means of asystematic, quantitative investigation with the aid of liquidextraction and spectrophotometry.

This phenomenon is not exclusive to molten salts as similarresults were also obtained from aqueous systems withcomparable composition.

34

EXTRACTION METALLURGYURANIUM LEACHING

Work continued on the investigation of the leaching ofuranium by electrochemical techniques.

It was shown that the electron-transfer stage in the dis-solution of UO2 takes place at the surface of the oxide. Amathematical relationship was derived to express the rate ofleaching of U02 in terms of fundamental thermodynamic andkinetic properties of the UO2 surfaces and the oxidisingreagent used to dissolve it. This relationship provides aninsight into the reason why some reagents are more effectivethan others and helps to explain many of the empiricallyobserved properties of uranium-leaching systems. The electro-chemical techniques developed for this study can be used inthe speeding up of laboratory testwork on leaching processesand in plant control.

PHYSICAL METALLURGYELECTRON MICROSCOPY

A scanning electron microscope was put into service duringthe year. This instrument is equipped with an X-ray micro-analyser with which extremely small inclusions in materialscan be analysed. One of the instrument's crystal spectrometerswas replaced by a non-dispersion system which allows theinstantaneous analysis of elements between fluorine anduranium. For the analysis of elements lighter than fluorinethe remaining crystal spectrometer must be used.

transverse waves excited by means of quartz plates could bemeasured along the (100] and 1110] directions of the crystals.Experiments were carried out to find a suitable couplingmedium between the quartz plate and the sample formeasurements at 4,2°K and higher.

CRYOGENIC IRRADIATION FACILITYA total of 92 runs was made of which 14 were liquefaction

runs to provide liquid helium for laboratory use. 16 wereirradiation and annealing runs, and 42 were test runs requiredto test the operation of new samples, etc. The reliability ofthe facility was improved to the degree that it is now possiblefor reactor operators to supervise the facility during pro-longed irradiations.

COMPARISON OF THERMAL AND FASTNEUTRON DAMAGE IN SILVER (Ag),COPPER (Cu) AND PLATINUM (Pt)

One specimen of each element was first irradiated in a fas:neutron flux to a dose of about 2,5 x l01Bn/cms, yieldingdefect densities of about 2,5 x 10"7. These specimens werestored ar 4,4°K. Subsequently, identical specimens wereirradiated in a thermal flux until the resistivity changes werethe same as those recorded for the fast neutron irradiation. Allspecimens were then transferred to the cryostat of the cryo-genic irradiation facility and were treated according to a veryclosely spaced isochronal annealing programme <aT=0,025T).In Pt, annealing stages Ic and Io were resolved for the firsttime after neutron irradiation. Stage IE for Pt is very promi-nent after both thermal and fast neutron damage, unlike Cuand other metals. Also, stage 1E was resolved in Ag.

This scanning tkclron microscope was instated and lakat into use duringthe year making the analysa of extremely soiatt inclusions in materialspossible.

X-RAY DIFFRACTIONMore than 150 samples of a variety of compounds were

examined routinely by means of standard X-ray equipment.A scientist was appointed to assist with the operation of

more sophisticated X-ray apparatus, and it is intended tosend him overseas for a period of training.

NEUTRON DIFFRACTIONAs a result of a thorough study of various experimental

parameters it was possible to improve the signal strength ofthe neutron diffractometer considerably. This study is beingcontinued.

A powder sample of K2Fe2O4 was investigated at roomtemperature. Further measurements on this material will becarried out at low temperatures to study the magneticstructure.

The on-line computer for the control of the apparatus isprogrammed in such a manner that the control programme foralmost any type of diffraction experiment can be producedfairly easily.

ELASTIC AND MAGNETIC PROPERTIESOF URANIUM COMPOUNDS

Preliminary work was done on the study of elastic proper-ties of uranium nitride. Flat faces were cut on uranium nitridesingle crystals so that the speeds of ultrasonic longitudinal and

MEASUREMENTS OF THE DAMAGEPRODUCTION RATE

Damage production was measured at temperatures between4,4°K and 300°K. These measurements indicate a strongtemperature and purity dependence. These effects are atpresent being investigated further with a number of sampleswhich are individually heated in the liquid helium streamof the cryogenic irradiation facility.

HIGH TEMPERATURE RECOVERYThe recovery of Cu, Ag, Pt and Au after neutron irradiation

was studied to 800°K. A marked influence of the annealingatmosphere upon the annealing behaviour was established.These experiments are being continued.

HIGH-PRESSURE EXPERIMENTThe object of the high-pressure experiment is to study the

pressure dependence of the recovery of radiation damage inmetals and to determine the activation energies and activationvolumes.

The integral system of high-pressure tube, sample andelectrical feedthrough was tested under pressure at roomtemperature. Low-temperature tests are in progress to deter-mine the parameters under which the applied pressure isstill hydrostatic.

THE EFFECT OF IRRADIATION ON THEINTERNAL FRICTION OF METALS

Gamma irradiation experiments performed on copper sofar support the basic ideas of the two-interstitial-thermal-conversion theory of defect production, rather than the single-interstitial theory. The "peak effect", an initial rise in dampingduring irradiation, reported in April by an American team.

35

was found at vibration frequencies approximately twentytimes higher than theirs. This problem is being treatedtheoretically.

The initial state of the specimen appears to influence strong-ly the type and extent of dislocation pinning observed atvarious low irradiation temperatures.

IRRADIATION DAMAGE INALUMINIUM ALLOYS

The first irradiation was successfully completed and thesamples-zone-refined and commercial-purity aluminium-tested for changes in compressive strength and creep. Themechanical property changes are being correlated with thechanges in microstructure, as observed by electron micro-scopy. The second irradiation will involve the effect of alloyconcentration on these properties. By varying the amountsof silicon and indium, it is hoped to influence the nudeationand growth of voids during irradiation.

TRANSPORT PROPERTIES OFIRRADIATED METALS

The existing facilities were extended to allow for themeasurement of the transverse . lagnetoresistance and Hallcoefficient in addition to the residual resistance and longi-tudinal magnetoresistance as a function of magnetic field So40 kilogauss at 4,2°K.

Copper foils of different purities were obtained on annealingin different atmospheres (residual resistance ratio 200 and1 000). The Hall coefficient differed considerably in thesetwo samples. After irradiation to a dose of l01*n/cmz (fast)in the SAFARI-1 reactor, the largest changes occuned in theabsolute values and the magnetic field dependence of theHall coefficient.

On annealing, the Hall coefficient varied considerably andits recovery occurred in a temperature range (300-400°C)different from that pertaining to the recovery of the residualelectrical resistance (200-370°C). This indicates that changesoccurred in the structure of the radiation damage, whichchanges will be investigated using electron microscopy.

36

The Board's Whole Body Counter ai the H. F. Verwoerd Hospital whichduring the year has been equipped with a new crystal which increases itsefficiency substantially.

on arrival at the mines from their homelands. Alter enjoyinga full diet from the time of their arrival, the values dropafter a few months. Bantu children who live in areas wherethe PCL incidence is very high, also show raised AFP bloodlevels.

With a view to investigating the cause of this illness,diethylnitrose was fed to baboons. The result was that theyalso showed increased blood levels and these animals arenow being observed to determine whether any of them «illdevelop primary liver cancer.

DIAGNOSTIC APPLICATION OFRADIOISOTOPES

The evaluation of ytterbium-169 in the chemical form ofcalcium trisodium diethylenetriaminopenta-acetate "'Yb asan agent for brain scanning and the determination of glome-rular nitration of individual kidneys was completed. Thisagent has proved to be superior to other agents and will beanother advance in the practise of nuclear medicine.

The use of gallium-67 for tracing malignant lymph nodeswas suspended as it appears that the test has no practicaladvantages.

MEDICAL AND BIOLOGICALTRANSPLANTED ORGAN REJECTION

The research in hyperacute renal rejection in goats, sensi-tized by prior skin grafting, is being continued. The presentwork involves biochemical investigations of this process.These experiments were done at Brookhaven National Labora-tories on goats that were either thymectomized, thymecto-mized and splenectomized, or thymectomized-splenectomizedand had also received ECIB many years ago. Contrary toexpectation these three groups of animals, after being skingrafted, rejected transplanted kidneys in the same way ascontrol animals. These results bear out the results of a fewresearch workers who are doubting the validity of the com-monly held views of the subdivision of lymphocytes in theT and B groups and their subgroups.

RADIO-IMMUNE ASSAYSThe application of these techniques has expanded enor-

mously in recent times. By using substances such as haptens,antibodies against them can be produced and this assay tech-nique can now be used to measure body fluid levels, not onlyof protein hormones such as insulin glucagon, growth hor-mone, etc. but also of aldosterone, oestrone, progesterone,testosterone, thyrocakitonin and other substances like renin,angeotensin, digitoxin and so forth.

When these assays have been standardised they will bepassed on to the hospital staff for routine applications.

PRIMARY LIVER CANCER (PLC)The determination of alpha-foeto-protein (AFP) levels in

normal, healthy, adult humans is being pursued to ascertainthe validity of the test when very low blood levels areencountered. Bantu mine workers have increased AFP levels

EXAMINATIONS DONE BY WHOLE-BODYCOUNTER

A. Diagnostic Investigations

<i) Vitamin B12 absorptionstudies

(ii) Vitamin B12 and I.F.absorption studies . .

(iii) Potassium body loaddeterminations . . . .

(iv) *7Ca studies(v) *7Ga present in body

<vi)1MYb biological halflives

(vii) 131I PVP loss throughintestinal canal . . . .

viii) 131I Sriolein fatty acidabsorptions

(ix)1311 present in stools(x)51Cr biological half-

lives(xi) 51Cr red corpuscle loss

through intestinal canal(xii) 51Cr present in stools .

Total

B. Health Physics Examinations

(i) Total number of health physics cases of AEB stall : 431.Nine cases of contamination were examined. Jn four ofthe cases internal contamination was discovered, but inno case did the contamination exceed 10% of the maxi-mum permissible body load.

(ii) Examinations for outside organisations:Nine persons were examined for possible internal radio-active contamination.

(iii) Private:One person was examined for internal radium contami-nation and such contamination was discovered, but itwas less than 10% of the maximum permissible body load.

Numberof

patients

23

11

4011

2

3

323

1

24

114

Numberof

counts

185

217

4212

1

7

18

36

9

19

546

Bio-logical

samples

—

—

18

—

51

4624

—

314

174

37

C. Medical Research

<i) "Cr pig wound samples .for Life Sciences Division

(iO^Na rabbit woundsamples for LifeSciences Division . . . .

(Hi) 131I insulin dynamics forLife Sciences Division . .

(iv) 1J1I-bound hormones forLife Sciences Division . .

(v) 7ISe rat liver serums for_Medical Research Council

(vi) Body potassium deter-minations for H.F.Verwoerd Hospital . . .

Total

Numberof

patients

—

—

1

—

—

16

17

Numberof

counts

—

—

7

—

—

31

38

Bio-logical

sample

24

75

9

2

10

—

120

D. Other Samples Counted

<i) Lead samples to testsuitability for shieldingDurooses

(ii) Dust samples for 22*Rafrom H2SO4 plants . .

Total . . . .

Number

3

. 22

. 25

Numberof

counts

7

22

29

E. Summary of nuclMes observed

Nuclide

Healthphysics

examinations Patients Samples Total

Cadmium-115Cesium-137Caldum-47Chromium-5]CobaIt-57Copper-64GaUium-67Gaffium-75Gold-198Iodine-125Iodine-131Potassium-40Radon-226Sodium-22Ytterbium-169

1441

4411

13

34

1859

1 —10

2129

- 22- 752 —

766

1441

19623431

1032

13650723752

LUNG CANCER AND EXPOSURE TORADON DAUGHTERS IN SOUTH AFRICANGOLD/URANIUM MINES

The results of the biostatistical investigation were presentedat UNO's 4th International Conference on the Peaceful Usesof Nuclear Energy, Geneva, 6-16th September, 1971. It isclear that any epidemiological study depends on improvedradon dosimetry by means of a personal dosimeter.

Information on amended overseas norms has constantlybeen gathered and brought to the attention of the GovernmentMining Engineer.

ISOTOPES AND RADIATION

AEROSOL PHYSICSThe efficiencies of activated charcoal filters in several venti-

lation systems were tested with methyl iodide. An improvedmethyl iodide generator was developed which keeps theconcentration constant to within 20% during the period oftesting.

Air samples from the reactor containment were analysedfor traces of organic vapours by means of a gas chromato-graph. The main source of these organic gases was established.It was found that methyl iodide is formed immediately afteriodine comes in contact with those gases.

The spinning disc.aerosol generator was used to generate10% mono-disperse polystyrene aerosols, which were fed intothe aerosol chamber. Aerosols in the range 0,5 to 5,0 microns,varying in concentration from 100 to 1 000 particles per cm3

were generated. The attachment of the decay products ofthoron to these aerosols was investigated. Using aluminizedplastic bags as aerosol holders, the characterisation of méthy-lène blue, sodium-chloride, carbon and copper aerosols pro-duced by special dispensers were investigated. Some of theseaerosols were used to investigate the behaviour of samplingdevices such as the cascade impactor and cascade centripeter,and to calibrate them. Efforts were made to characterise aDOP aerosol which is used as a standard test aerosol.

Radioactive air samples taken on glass fibre filter papersand membrane filters were autoradiographically investigatedby means of nuclear emulsions. Both alpha and beta trackswere found, and the attachment between activity and dustparticles was investigated. Plutonium aerosols present duringoperational work at the Reactor Building and the WasteTreatment Building were investigated in this fashion. Theattachment between the decay products of thoron and poly-styrene particles was also investigated as well as paniculateactivity from nuclear explosion fallout. Use was made of thecascade centripeter to determine the particle size distributionof the plutonium aerosol mentioned above, as well as ofnuclear explosion fallout

The condensation nucleus counter was used to measurethe efficiency of absolute filters and to test the efBciencyof dust-free installations. The routine analysis by means ofsampling packs of the gaseous air-bome activity releasedfrom the exhaust stacks of the Reactor Building and theWaste Treatment Building was continued.

SHIELDING STUDIESThe rig for the experimental study of the flow of neutrons

through conical tube openings in water shields was com-pleted. The results of a series of flux measurements of thermal,epithermal and fast neutrons are being processed at present.A theoretical study to explain the results was also commenced.

The computer programme for the calculation of shieldthicknesses for gamma sources was tested and is being used.

GEOLOGYTwo senior officers devoted considerable time to funda-

mental research and the following projects were completed.(1) A study of the favourability criteria which could be

applied in the search for uranium in the major sedimen-tary geological formations in South Africa.

(2) A study of various sedimentary basins in central South-West Africa the results of which may serve to delineatepossible metallogenic provinces in South-West Africa andadjoining territories. This project is being extended.

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RESEARCH REACTOR

REACTOR OPERATIONSAFARI-1 was operated throughout the year on a 24 hour,

five-day-per-week basis from Mondays to Saturday mornings.The nominal power level from April until the end of Novemberwas limited to 8,5 MW to accommodate a materials-testirradiation in the core. Before and after this period, the powerlevel was set at 10 MW, but was raised in some instances, onrequest, up to a maximum of 20 MW.

The existing core configuration was not altered during1971, and consisted of 27 fuel elements and 5 control rods.Five cores were loaded during the year, up to Cycle 17.Increasing negative reactivity inventories resulted in lessefficient fuel utilisation, and it was decided to raise thenominal fuel element "'U content from 162 g to 200 g infuture orders.

The fuel inventory at the end of the year consisted of4.13 7 kg of MiU in the reactor core, 21,705 kg of new elementsin the vault, and 5,539 kg of depleted and partially depletedelements in the storage pool.

Significant operating data for the year are given below:

Period1 Jan. 1971-31 Dec. 1971

Average power, MW 9,0Accumulated energy. MWd 1 665MBU bumup, grams 2 110Number of days reactor at power 226Number of capsules irradiated 1847Number of unscheduled shutdowns Il l% of unscheduled shutdowns per operating day . 49Number of major experiments operated 5

This new plug incorporating thermocouple pockets was instated in thesut-pile room of SAFARI I.

REACTOR SYSTEMS AND COMPONENTSIn general, SAFARI-] performed well with a minimum of

equipment failures occurring, apart from spurious instrumen-tation responses causing unscheduled shutdowns.

High pool-water activities were experienced on two occa-sions. Analysis showed, however, that these activities werenot attributable to fission products, but to 24Na formed byneutron interactions with aluminium. It was concluded thatfine aluminium swarf, produced by fuel element cuttingoperations, became disturbed and suspended in the poolwhen unusual agitation of the water occurred.

A plug incorporating thermocouple pockets was installedin the sub-pile room under core position G-3 for instrumentperformance tests. The purpose of the new plug was to provideadditional locations for extra temperature channels. The newlocations are closer to the core than the original pockets, andthus permit faster instrument response times to be obtained.

The nuclear and process instrumentation continued to causean unduly large number of unscheduled shutdowns. A revisedinterlock system and additional instrument channels to pro-vide a two-out-of-three control philosophy will be installedearly in 1972.

The original logarithmic nuclear channel N-2 was replacedby a modern wide-range logarithmic channel which alsoprovides linear safety protection as an additional feature.Two more of these channels will be ordered, and they willprovide the basis of the revised interlock system.

Lead shielding doors were installed in the process wing toshield the access areas from the primary coolant systempumps and the degasifler. These doors will be closed during20 MW operation and in the event of accidents.

REACTOR FACILITIESAn underwater neutron radiography facility was used

during the year to provide photographs of the internal stmc-rure of the Chouca-P rig. The method proved to be useful andeffective for the radiography of radioactive equipment oflimited size. Development of a facility for out-of-pool neutronradiography is in progress.

The installation of an additional pneumatic rabbit irradia-tion facility, similar to the original one, was commenced.This facility will be in the Chemistry Building.

A second hydraulic rabbit facility, also similar to theoriginal facility, was designed and will be installed earlyin 1972.

A "fast" pneumatic rabbit system, with transport time ofthe capsules between the core and the counting station onthe instrument gallery of the order of one second, is beingdesigned.

A new hatch for the reactor vessel was manufactured andtested during 1971. This hatch, when installed, will allowthe insertion of straight, vertical rigs directly into the corethrough access holes drilled where required in the hatch.

DETERMINATION OF REACTORPARAMETERS AND SPECIAL TESTS

Out-of-pile pressure measurements on a dummy fuelelement were conducted in the flow test facility. Similarmeasurements in core positions E-6 and B-6 were carried out,and it was concluded that the flow pattern is uniform radiallyacross the core. Individual elements exhibited similar flow-pressure characteristics to those obtained in the flow testfacility.

Two dummy "half' fuel elements were manufacturedduring the year for structural-integrity tests. The first of theseproved to be defective, and modifications, to correct thesedefects were built into the second durnmy element whichperformed satisfactorily. A third dummyfrtrid a "live" elementwill be manufactured during the early part of 1972 forfinal testing.

IRRADIATIONS AND EXPERIMENTSThree major rigs which were installed before the end of

1970 continued to operate. These were the cryogenic irradia-tion facility, the thermal neutron beam rig in the lower westthrough-tube, and the neutron diffraction rig in beam tubeno. 5.

In addition, two other major rigs were installed during1971. One was the Chouca-P capsule irradiation rig, whichwas removed late, in the year on completion of the irradiation.Neutron radiographs indicated that one of the capsules in therig had not been correctly manufactured. However, it wasdecided that the capsule presented no hazard and the irra-diation was continued successfully. Post-irradiation handlingof the Chouca-P rig in the hot-cells was commenced at theend of the year.

The other major rig to be installed and commissioned wasa neutron beam facility in beam tube no. I.

Numerous measurements were carried out to determine theneutron flux distribution in hollow conical tubes in thepoolside facility.

Isotope production continued to increase during 1971.The facilities used for this were the pneumatic and hydraulicrabbit systems, the poolside rack, hollow beryllium elementsin the core, a rig in beam tube no. 6 and a routing capsulein the poolside facility.

A Chouca-O rig for carrying out fast-neutron irradiationswas ordered during the year, and should be commissionedearly in 1972. The sample holder is being manufacturedlocally.

A rack was manufactured for providing a gamma radiationflux in the cryogenic irradiation facility in the storage poolposition. This rack can accept eight irradiated fuel elements,and is suspended in the pool from a beam. It is also possibleto place the cobalt pins, which are at present being activatedin the core, in this rack.

Irradiations were carried out on organic materials in arack in the poolside facility. These irradiations were of apreliminary nature, and were intended to obtain an estimateof the limitation on total irradiation time imposed by gasevolution and pressure build-up in the quartz ampoules. Thelead shielding blocks in the poolside facility reJuce thegamma flux, the major cause of gas evolution, by a factorof approximately 100.

REACTOR FUELA second shipment of 24 spent fuel elements and control

rods was sent to the United Kingdom for reprocessing duringJuly. A consignment of 74 new fuel elements was receivedfrom the United Kingdom during August.

TRAINING OF REACTOR STAFFThree formal courses were conducted to enable operators

to become Licensed or Senior Licensed Reactor Operators.The five shifts now consist of six Senior Licensed Operatorsand four Licensed Operators. Five Shift Supervisors wereappointed.

WASTE DISPOSALLiquid and solid radioactive waste was received from

various plants and laboratories on the site as well as fromoutside organisations, and was treated in the waste treatmentplant for disposal.

Under the permit granted to the Board by the Departmentof Water Affairs, 267 megalitres of decontaminated liquidwaste containing 376,1 millicuries of residual activity weredischarged to the Crocodile River.

In the medium-active waste evaporator, 405 000 litres ofwaste were evaporated. The highly-active waste evaporatorwas also successfully operated and 305 000 litres of highly-active waste were evaporated. The concentrate obtained inthis manner was solidified by means of a cement-vermiculitemixture. The two evaporators together produced 5 296,1 kgof solid waste. This was buried together with the other wasteat the Board's site for the disposal of radioactive waste atPelindaba.

Approximately 5 210 kg of low-level solid waste werecompressed in the baling press and a volume reduction of5,3:1 was achieved. A total of 200 drums of solid waste,consisting of non-compressible, compressible and solidevaporator concentrate were buried.

19 178 articles were washed in the laundry for radioactivelycontaminated clothing. Coloured tape was sewn to the collarsof 833 garments and a large number of garments was repaired.

In the decontamination centre, 594 articles were success-fully decontaminated including various large items fromNIM, from the Chemistry Division and from the ReactorBuilding.

A facility for the temporary storage of radioactive sourcesof up to approximately 1 Ci cobalt-60 was completed andwill be put into service shortly.

41

INSTRUMENTATION

GENERALA large number and variety of specialised instruments were

developed and constructed. Although project co-ordinationof mixed projects, i.e. not purely electronic systems, is stilltroublesome, on the whole a high standard of support couldbe given to the other research divisions.

FACILITY FOR THE AUTOMATICCOLLECTION AND ANALYSIS OFNUCLEAR PHYSICS DATA

Additions were made to GIM, the General InterfaceModule, to permit the coupling of the graphic display unit,which is almost completed. As an interim measure, a storagescope was implemented as a very fast plotter, using standardplotter programmes. A mini-cassette unit is now used to copewith the large number of programmes available. This hasenhanced the operational speed and eliminates paper tapewastage.

DEVELOPMENT OF NUCLEARINSTRUMENT MODULES (NIM)

A digital thermometer using a crystal of special cut as itssensor was developed. This cut suppressed higher ordertemperature coefficients of the crystal's oscillating frequency,so that a linear frequency scale with high accuracy andresolution, is achieved.

MAGNETIC FIELD STABILIZATION BY NMRNuclear Magnetic Resonance (NMR) is a conventional,

powerful method for accurately measuring and calibrating amagnetic field. In this project, however, the NMR apparatuswill form part of a closed-loop control system for the deflec-ting magnet of the Van de Graaff accelerator. This system willenable the operator to dial the desired field strength directlyinstead of the present time-consuming setting-up procedure.Owing to the resonant nature of the measuring technique, anerror signal is produced only within about 0,1% of the setvalue. The NMR-Ioop, therefore, has to be backed up by aconventional current control system, which steers the fieldto the approximate desired value. A search mode is theninitiated until lock-in is achieved. The various subsystemswere developed and their interaction is being studied.

EMERGENCY CONTROL CENTREThe Emergency Control Centre was moved to the new

Main Entrance Building. This opportunity was used to com-pletely redesign the site communication system, and torationalize the safety and emergency control network. Forthe first time all emergency, security and communicationsrequirements are now properly co-ordinated, and reliableequipment is interconnected in a systematic fashion andlogically presented in a new control room.

MAINTENANCEMaintenance and inspection service of electronic and

process instruments continued at a high level, and electro-mechanical equipment, especially computer peripherals, cannow also be handled satisfactorily.

OPERATING SYSTEM FOR MINI-COMPUTERS

To eliminate duplication of efforts at system programmingwhenever a new application of computer control is imple-mented, it was decided to study the common structure of suchprogramming families. This led to a study of computeroperating systems in general and an attempt to develop amodular or library-like universal system, from which a specificsystem can be assembled for a specific purpose. The structureof such a system was designed and reasonably detailed flov. •diagrams drawn up. Work will continue in parallel with thestandardisation of interfacing between mini-computers andexperiments or processes, which is reported below.

OTHER SITE SERVICES

OPERATIONThe supply services were successftilly operated, and pro-

duction figures for the year are as follows:Domestic and process water 623 megalitresDrinking water 10,4 megalitresDemineralised water 3,7 megalitresLiquid nitrogen 248,6 kilolitresCompressed air as required

Work is in hand to raise the weir in the Crocodile River sothat there can be a larger reserve of water for purificationduring times of drought.

Standardisation of Interfacing between Mini-computer* and Experiments or Processes

The international CAMAC system used at Pelindaba is amodular system specification for interfacing a digital con-troller or computer to an experiment or process. The specifi-cations include electrical and mechanical standards to ensurecompatibility between units developed by the various labora-tories or manufacturers. Work was done on the developmentof a specific crate controller for use with Hewlett-Packardcomputers, and also on other specific modules. This project,with its emphasis on the modular nature of both hardwareand software, ties in well with the standard operatingsystem project.

The PACE 231R analogue computer facilitates the develop-ment of digital computer-based control systems, the controlledprocess being simulated on the analogue computer duringthis phase.

ANALYTICAL SERVICESComplete analytical control

effluent and cooling systems,analyses were carried out :Water LaboratoryRadiochemical Laboratory

was exercised over all water.In this respect the following

3 596 analyses992 analyses of which482 were carried out with

a view to thedischarge of effluentin the CrocodileRiver.

The following analyses were performed by the Metallurgicaland General Laboratory and by the Radiochemical Laboratoryon behalf of other divisions of the Board:

523 specifications analysesmetals

68 general analyses.

42

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ENGINEERING SERVICESDESIGN

In the Design Department, 68 design projects were com-pleted ami six pressure vessels were designed and approvedlor smice. Some of the major projects included the fastirradiation and counting facility, the activation analysisrabbit system and the cryomagnetic facility. Since economicsof manufacture are largely dependent on the quality ofdesign, serious efforts have been made to implement thebasic concepts of value analysis.

The training of learner draughtsmen was transferred to theTechnical Training Department.

MANUFACTURINGA portion of the Instrument Workshop was partitioned off

and provided with air-conditioning. This was necessitatedby the increasing demand for high-precision machining whichcan be carried out satisfactorily only in an environment ofconstant temperature and filtered air, and in which "cleancondition" practices can be exercised. Two high-precisionlathes were transferred to this area, and a milling machinesuitable for working to extremely fine tolerances waspurchased.

Manufacturing projects of note were the cryomagneticfacility, 'he rotating irradiation facility, a number of rabbitsystems, and components for the Telatom microscope.

A considerable amount of development work was carriedout on techniques involved in the manufacture of SAFARI-1fuel elements and on the special fast neutron irradiationfacility, the so-called half fuel element.

Operation of the plasma arc cutting machine in the Sheet-metal Workshop showed that there were several safetyhazards in the form of an intolerably high noise level, ultra-violet radiation and toxic gases. These problems were over-come by building a sound-proof cubicle with an air extractionsystem around the facility.

44

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PLANNINGAs a result of the increased implementation of planned

preventive maintenante, the service periods of machinesand apparatus have been extended and breakdowns havevirtually been eliminated.

INSPECTIONIn addition to the normal inspection services and quality

control carried out an appreciable volume of contractual workwas also executed on behalf of other Divisions of the Boardand an ever-increasing number of special services are beingrequested.

CONSTRUCTION AND MAINTENANCESince the introduction of preventive maintenance, and

because of the resultant increase in efficiency of operation,it was possible to extend the scope of maintenance withoutincreasing staff.

A considerable amount of construction and erection workwas carried out, the most notable of which was on theRadiation Technology Buildinj

BUILDINGS AND CIVIL MAINTENANCEThe Radiation Technology Building, the Woiks/Tianspoit

Building and the Main Ent ranee Building weie completedduring the year. Building operations are in an ad\antedstage on the lew Physics Building and on the extensions tothe Chemistry Building, and work on the External RelationsBuilding and the Reactor Development Building has com-menced.

The maintenance ol buildings and the big demand lorcivil alterations placed an ever-increasing load on theWorks Department.

COMPUTER SERVICESOwing to the increase in computations, two lull shuts

were worked during live days per week and a shif; lorSaturdays was introduced during the second hall ol the year.Programmes of up to 30 minutes were run during the day,and the longer programmes during the evenings.

During the year, tenders were invited for a larger amifaster computer and it was decided to replace the existingIBM System/360, model 40H computer with an IBM System/370, model 155IH with a last memory' of 768 k bytes. Toaugment this, faster disc drives and magnetic tape units werealso ordered, as well as two remote job entry terminals andan interactive terminal. A special print train was retchedfor the printing out of INIS (International Nuclear InformationSystem) information.

Extensive mathematical services were rendered by I heprogramming group, especially in regard to numeriialmethods.

45

t :

EXTERNAL RELATIONS

INTERNATIONAL ATOMIC ENERGYAGENCYFIFTEENTH GENERAL CONFERENCEThe South African delegation to the Fifteenth General

Conference of the International Atomic Energy Agency, heldin Vienna during September, was composed of:Dr A J. A. Roux - President of the Atomic Energy Board(Leader)Mr D. B. Sole - South African Ambassador in Cologne andGovernor for South Africa on the Board of Governors of theAgencyMr K. R. S. von Schimding - South Africa's Resident Repre-sentative to the Agency in ViennaMr H. H. van Niekerk - Counsellor, Multilateral Relations,Department of Foreign AffairsMr J. O. Tattersall - Manager, Licensing, Atomic EnergyBoard andMr S. W. van der Merwe - Deputy Director, External Relations,Atomic Energy Board.

During the conference attention was specially directed to:(a) The Non-Proliferation Treaty and the safeguards measures

drafted by the Agency to satisfy the requirements of theNon-Proliferation Treaty for the international control ofnuclear material;

(b) Technical assistance to developing countries to enablethem to utilise the advantages of the peaceful uses ofnuclear energy, especially that of nuclear power; and

(c) the pollution of the environment.

FOURTH INTERNATIONALCONFERENCE ON THE PEACEFULUSES OF NUCLEAR ENERGY

The Fourth International Conference on the PeacefulUses of Nuclear Energy arranged by the United Nations incollaboration with the International Atomic Energy Agency,was held in Geneva from 6th to 16th September. The SouthAfrican delegation consisted of:Dr A. J. A. Roux / President of the Atomic Energy Board(Leader)Prof. S. F. Oosthuizen / President of the South AfricanMedical and Dental CouncilMr J. W. Shilling / Chairman of the Nuclear Fuels Corpora-tion of South Africa (Pty) Ltd andDr R. L. Straszacker / Chairman of the Electricity SupplyCommission.

Representatives of the Atomic Energy Board, the UraniumEnrichment Corporation, ESCOM, the uranium and otherindustries, the Department of Agricultural Technical Servicesand the Department of Foreign Affairs assisted the delegationas advisers.

Of the papers submitted by South Africa, the following sixwere accepted—the first four for oral representation :1. A biostatistical investigation of lung cancer incidence in

South African gold/uranium mines-J. K. Basson, C. H.Wyndham, A. J. A. Heyns, C P. S. Barnard, A. H. Munroand I. Webster.

2. A discussion of nuclear plant safety with reference toother hazards experienced by the community—J. O. Tattersall.

3. Some aspects of the nuclear fiiel cycle and their relationshipto the production of raw materials- S. A. Young.

4. The use of radioisotopes and radiation in agriculture inSouth Africa - F. J. Haasbroek.

5. Radiation polymerisation of monomer impregnated SouthAfrican timbers - R. A. Basson.

6. Forecasting the role of nuclear energy in South Africa -G. F. B. Tremeer and E. J. Maunders.

IAEA RESEARCH CONTRACTSResearch contracts for the following projects were renewed :

1. Life Span and Metabolism in anaemias induced by chemi-cals and abnormal haemoglobins. (S.A. Institute of MedicalReseaich).

2. Radioisotope investigation of iron absorption in humans.(University of the Witwatersrand). (Part of a joint WHO/IAEA co-ordinated research programme on iron absorp-tion).

INTERNATIONAL NUCLEAR INFORMATIONSYSTEM (INIS)

The International Nuclear Information System maintainedits planned rate of development throughout the first fourmonths of 1971, thus completing a successful first 12-monthperiod of operation. In May, the monthly ATOMINDEX wasrefashioned to include descriptor (keyword) indexing of eachreference. Some 160 copies of the printed ATOMINDEX wereposted to organizations and persons throughout South Africaeach month. Requests for reports and journal articles werehandled in collaboration with the Library. Full texts of 30reports on microfiche were obtained from INIS headquartersin Vienna.

Descriptor indexing of the ATOMINDEX has opened thedoor to an SDI (select dissemination of information) serviceto scientists, using the monthly magnetic tapes as source.AU the necessary ancillary hardware required by the Com-puting Centre was acquired and tested. Software for retrievalwork is being prepared by INIS headquarters. Programmesshould become available in the course of 1972. All scientistsat Pelindaba were invited to submit interest profiles in orderto prepare for the introduction of a specialized informationservice.

The assistance of the State Library and the JohannesburgPublic Library was invoked (and readily provided) to facilitatethe search for relevant input material for INIS. Several otherorganizations also brought relevant rejxirts and articles tothe notice of the INIS Liaison Officer.

In July, a panel of experts on subject scope expansionrecommended that the INIS subject scope be expanded to

46

its full size at the beginning of 1972. This recommendationwas endorsed by the Board of Governors of the Agency. Thismeans that, as from 1st January, 1972, the number of inputitems will increase considerably. It also means that theSystem as a whole will provide much more information ofimportance to scientists working in the nuclear field. TheSouth African INIS Liaison Office has geared itself to meetthe new demands for 1972.

During December a decision was taken to integrate theINIS Liaison Office with the Library of the Atomic EnergyBoard, with effect from 1st January, 1972.

OVERSEAS VISITSThe President of the Board visited Europe in June, and

again in September.The international Conference on Fast Reactors held in

Aix-en-Provence was attended by five senior officers of theBoard, who subsequently also attended the Fourth GenevaConference. In addition, some of them as well as othersenior officers visited several European nuclear installationswith the object of studying various factors related to theBoard's research programme and in view of its plans to erecta general hot-cell complex.

Various countries were visited by the'Director : Chemistry,in the interest of the Board's programme on applied radiationtechnology.

The Director : Geology took part in a NATO AdvancedStudy Course on Methods of Prospecting for UraniumMetals, in London.

The Director : Physics conducted research at the EnricoFermi Institute, Chicago during an overseas visit and attendedsymposiums at München and Triest as well as the Inter-national Conference on Particle Physics at Amsterdam.

VISITORS FROM OVERSEASProfessor A. Seeger, Director of the Max Planck Institute

for Metats Research at Stuttgart and Professor of Solid StateScience at Stuttgart University, arrived in September to takepart in the Board's programme of solid state research. Hewill stay for about six months. Prof. Seeger has already writtenseveral papers here and has given lectures at universitiesand other institutions.

Prof. H. A. Weidenmüller of the University of Heidelberg,who is one of the directors of the Max Planck Institute there,visited Pelindtiba during August. In addition to presenting anumber of icctures and discussions, he did research on theo-retical nuclear structure in collaboration with a scientist ofthe Atomic Energy Board.

Prof. Y. Ne'eman of the Tel Aviv University paid a one-dayvisit to Pelindaba.

The Board also received numerous one-day visits fromoverseas guests of other institutions. Among these weredistinguished statesmen, scientists, university and industrialleaders from various countries including France, Germany,Holland, Japan, Portugal and Rhodesia. The Board alsoreceived a one-day visit from the Madagascar ministerialmission.

VISITS TO PELINDABASeventeen scientific societies and other interested groups,

totalling 443 persons, visited Pelindaba during the year.Visitors on the two Public Open Days totalled 590.

The new. method of having two full days set aside eachyear especially for school groups was put into operation anda total of 638 scholars were received, compared with 393 in1970. The new system is a considerable improvement on theold method which entailed afternoon visits by groups of 60.

Twenty-six representatives of various diplomatic missionsvisited Pelindaba and were entertained to lunch by thePresident.

LIBRARY SERVICES

ACQUISITIONS AND LOANSA total of I 167 new books and 1 189 volumes of bound

periodicals were added to the collection during the year.The bound periodicals now amount to more than 17 000volumes. Research organizations contributed 8 814 reportsduring the year, bringing the total in the library to more than122 000. A total of 7 896 publications were issued to membersof staff, 419 publications were lent to other organizations,and 3 1Ï3 publications were borrowed from other libraries.

INFORMATION SERVICESThese services are developing slowly. Literature searches

were carried on as usual.

REPROGRAPHIC SERVICE302 600 photocopies were made with the aid of the photo-

static machine. 7 628 microfiche prints were made.

SCIENTIFIC GATHERINGSThe following scientific gatherings were attended by

officers of the Board:* South African Chemical Institute, 21st Convention, Grahams-

town (February)* South African Association of Physicists in Medicine and

Biology, Pelindaba (March)* International Conference on Liquid Extraction, The Hague,

Holland (April)* Symposium on Automatic Control Systems in Mineral

Processing Plants, Brisbane (May)•Congress of the Society of South African Pathologists,

Pretoria (June)•Tenth Biennial Conference on Carbon and Graphite,

Bethlehem, Pennsylvania (June)* World Energy Conference, Bucharest (June)

IAEA Fourth Conference on Plasma Physics and ControlledNuclear Fusion Research, Wisconsin, U.S.A. (June)

•South African Institute for Physics, 16th Annual Congress,Cape Town (July)

* Seminar Series in Theoretical Physics, 6th Annual Seminar,Cape Town (July)

* International Association for Dental Research, SouthAfrican Division: Fifth Scientific Congress, Johannesburg(August)

* International Congress on Statistical Properties of Nuclei,Albany, New York (August)

•International Conference on Thermal Analysis (ICTA-III),Davos, Switzerland (August)

* Conference on Topics in Polymer Chemistry, Johannesburg(September)

* Fourth United Nations International Conference on thePeaceful Uses of Atomic Energy, Geneva, Switzerland(September)

•South African Ceramic Society: Symposium on CeramicFabrication, Olifantsfontein (September)IAEA International Symposium on Rapid Methods forMeasuring Radioactivity in the Environment, Neuherberg,Germany (September)CEA International Meeting on Fast Reactors, Aix-en-Provence, France (September)NATO Advanced Study Institute: International Meeting onMethods for Prospecting for Uranium Minerals, London(September)

•Symposium on the Future of Nuclear Physics in SouthAfrica, Pretoria (November)

*At the gatherings marked with an asterisk, papers by officers ofthe Board were presented.

47

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LICENSING

48

STAFFThe basic organization of the Licensing Branch was fully

established during the year and now consists of three divisionsdealing with Safety Evaluation, Standards and Inspection.The senior staff for each division have all joined the Boardand, in addition, a number of other appointments have beenmade. Several members of the staff are overseas for trainingat present.

SAFETY CRITERIAData relating to general hazards and safety standards, which

were collected during 1970, are being studied with a view toestablishing basic safety criteria applicable to nuclear instal-lations. Information is being gathered continually from manysources, and the criteria will be reassessed periodically in thelight of current knowledge.

A paper discussing some present trends in safety matterswas presented at the Fourth International Conference on thePeaceful Uses of Atomic Energy at Geneva.

A cost-benefit type of approach will be included in thefuture, and study of this method of assessment is continuing.

SAFETY ASSESSMENTDiscussions relating to plant saftey, safety features, and

appropriate methods of evaluation, were held with ESCOM,reactor suppliers and consultants, both in South Africa andoverseas.

The discussions indicated certain boundary conditions; andfurther studies are in hand to establish more detailed proce-dures which can be successfully applied to the various reactortypes.

Experience is being gained in this field by applying theabove knowledge, as it becomes available, to a comprehensivesurvey of the Board's own installations.

Special attention is being devoted to the problems of modesof failure arising in thick-walled pressure vessels. This studyis proceeding in parallel with the inspection limitations out-lined elsewhere and consideration of the necessary designcriteria.

Trie study and procurement of suitable computer pro-grammes for use in the evaluation procedure is continuing.

COMPONENT AND PLANT RELIABILITYDiscussions were held with ESCOM and potential South

African manufacturers of reactor components regardingquality control as at present practised in South Africa, andthe development of suitable techniques to meet nuclearstandards. These discussions resulted in the production of apreliminary guide to quality control which is at presentunder consideration by interested parties. The guide makesrecommendations which can be incorporated in the enquirydocuments.

Studies of techniques for establishing the size and positionof defects in thick plates indicate the fact that this is amajor inspection problem. Means of improving the inspectiontechniques are being considered in paraiiei with studiesrelative to modes of failure and the establishment of rigorousdesign criteria.

DATA PROCESSING AND STORAGEA study is being made of the quantity of data which is

currently available, and that which is required in order tofulfill the responsibilities of the Licensing Branch. This studyalso involves the problems of data storage and retrieval.Various systems are being assessed in ordei to establish whichone is most applicable to the needs of the Branch.

CONTROL OF DEVELOPMENT AROUNDREACTOR SITES

As a result of the principles agreed in 1970 at a meetingbetween the Department of Planning, ESCOM and the Board,and at a subsequent meeting which included the local authori-ties, further studies were made of the problems involved inthe development of the Duinefontein and Pelindaba sites.

The population density and meteorological details havebeen examined for both sites and ?s a result preliminarysafety criteria and maximum permissible release rates arc-being formulated.

Additional data is being collected in order to confirm andimprove the validity of the projected population figures duringthe lifetime of the nuclear installation.

NUCLEAR SAFETY ADVISORYCOMMITTEE

During the year the Atomic Energy Board acceptedrecommendations regarding the establishment of a NuclearSafety Advisory Committee. The membership of the Commit-tee is currently being decided and it is expected that it willhold its first meeting early in 1972.

49

The total number of persons in the service of the Boardon 31 st December, 1971, was 948.

The distribution of the administrative, scientific andtechnical staff is shown in the table below.

Permanent TemporaryAdministrative StaffMale 71 2Female 9 1

Scientific StaffMale 160 3Female 2 1

Technical StaffMale 237 2Female 24 4

Experimental OfficersMale 89 1Female 19 0

Miscellaneous

Total

MaleFemale

Total . . .

. . . 100

. . . 75141

724182

948

p'5V

BURSARS i •>"¥*••;>.::There are five persons at present continuing their studies j_ ,'̂ fii-' c-j

with post-graduate bursaries and 37 with pre-graduate ',,, •'.x'~°"s'bursaries.

TECHNICAL TRAININGAt the end of 1971, there were 71 learner technicians in

six directions of training, 90 apprentices in eight trades andseven Ie - mer draughtsmen undergoing training at Pelindaba.

FINANCIAL AID TO UNIVERSITIES AND RESEARCH INSTITUTIONSA total of 80 research grants were made to universities

and research institutions. The total value of these grants wasR187 26'l,00.

Details of the grantees and projects are as follows:

DEPARTMENT OFOBSTETRICS ANDGYNAECOLOGY

UNIVERSITY OF CAPETOWNDEPARTMENT OF CIVILENGINEERING

Prof. M. F. KaplanTo iiivestigate the properties of concrete made withlocal materials with reference to its use in theshielding and containment of nuclear reactors.

DEPARTMENT OF GEOLOGY

Prof. J. de Villiers and Mr. R. Jacobs (PrecambrianResearch Unit)The Geology of the area east of the confluence of theKhan and Swakop Rivers. South-West Africa.

Prof. J. de Villiers and Mr. J. H. W. WardPegmatites in Namaqualand.

DEPARTMENT OF MEDICINE

Dr. S. Epstein (Endocrinology)To study the effect of hormones on DNA synthesisin hypophysectomised animals and animals renderedprotein calorie deficient. This involves the use oftritiated thymidine.

Prof. J. D. L. Hansen (Clinical Nutrition ResearchUnit)Continuation of the study of the body compositionof children in various states of illness with particularrelation to their nutritional status, as well as thebody composition of new-born infants in relationshipto placenul function and birth weight.

Dr. P. Keller (Endocrine Research Group)Continuation of the investigation of insulin-likeactivity and (he measuremem of insulin in normalsand in cases of potential diabetes, pancreatitis, etc.

Dr. B.L. PimstoneThe following studies:(a) The role of protein depletion 'ndamino acids in

growth hormone homcostasis.(b) Labelled growth hormone kinetics in protein-

calorie malnutrition.(c) Insulin secretion in protein-calorie malnutrition.(d) Growth hormone secretion and kinetics in

liver disease.(e) Growth hormone and the kidney-autoradto-

graphic and tracer kinetic studies.(f) The endocrine control of albumin synthesis and

catabolism.

(g) The development of new radioimmunoassaytechniques for the measurement of the followinghormones:

<i) Rat growth hormone(ii) Glucagon

(iii) Proinsulin(iv) Parathyroid hormone(v) ACTH

<h> The evaluation of bone metabolism in proteindepletion states:

(i) Histology - tetrachrome staining(ii) Tctracyclinc labelling-the measurement

of bone accretion(iii) Caicium-47 kinetics(iv) Stable strontium kinetics

Dr. R. RabkinTo investigate GH metabolism, with particularreference to the following aspens:(a) The role of the kidney and liver in health.(b) The role of the kidney or liver in disease slates

associated with elevated growth hormone levels,e.g. kwashiorkor, renal disease, porphyria.

(c) The effect of various renal diseases on theability of the kidney to regulate plasma GH levels,and ils relationship to impaired groivth incertain disorders or renal tubular function, e.g.renal tubular acidosis.

(ill The nature of GH metabolism in the kidney andliver. In particular to what extent does thekidney excrete and/or degrade this hormone.

(e) The mechanism of GH transport imo proximaltubular cells. In particular is the transport activeor passive, specific or non-specific.

Dr. S.J. SaundersContinuation of the study of the transport of aminoacids in the renal tubule and the small intestine,with special emphasis on the effects of thyroid hor-mone and malnutrition.

Dr. R. H. Stead (Clinical Nutrition Research Unit)Continuation of an investigation of digestive effi-ciency, amino acid flux and protein synthesis inselected organs in expc;:mental protein caloriemalnutrition.

DEPARTMENT OF NUCLEARMEDICINE

Dr, E. W. Dowdlc (Renal Metabolic ResearchGroup)Continuation of a study of haem synthesis inhuman and experimental porphyria.

Prof. D. A. DaveyContinuation of the measurement by radio-immunoassay of Iutcinising hormone <LH> andfollicle stimulating hormone (FSH) in the suppres-sion and stimulation ol ovulation and of humanplacenta! laçtogen <HPL) as a mt'Jsurt* of placcntolfunction.

UNIVERSITY OF NATAL

DEPARTMENT OFBIOLOGICAL SCIENCE

Pror. T. A. Villiers el al.Continuation of studies in the hormonal control ofprotein synthesis.

DEPARTMENT OF CHEMICALENGINEERING

Prof. E. T. WoodburnA continuation of a generalised study ol absorptioncolumns with particular reference to the scrubbingof atmospheric pollutants.

Prof. E. T. Woodburn and Mr. J. R. FitzgeraldAtmospheric dispersion and removal of jHillutanis.

Prof. E. T. Woodburn et aïThe investigation of computer control of a pilotflotation network based on an adaptive mathematicalmodel.

DEPARTMENT OF CHEMICALPATHOLOGY

Prof. S. M. Joubert (Intermediary MetabolismResearch Unit)The following projects:(a) Experimental porphyria

(i) Iron overload and its effect on urinaryporphyrin excretion,

(ii) Chloroquine idiosyncracy in symptomaticporphyria.

(iii) Tritium incorporation into liver haem inexperimental porphyria.

(b) Blood glucose homcostasis(i; Alcoholic ftypoglycacmia.

(ii) Methodology relating to immui;oas<aytechniques.

(iii> Collaborative studies.(c) Sensory biology.

51

DEPARTMENT OF BOTANY

Prof, C H. BornmanContinuation of a study of hormone movement inrespect of tissues in which they move, as «veil astheir rate of movement, in an attempt to elucidatetheir possible mechanism of action in:(a) abscission of plant pans; and(b) differentiation of tissues and organs in callus

cultures.

DEPARTMENT OF CHEMISTRY

Dr. C. G. Gordon-Gray (Senecio Alkaloids Bio-synthetic Group)Continuation of an investigation into the mode ofsynthesis of nitrogenous bases (pyrrolozidine alka-loids) in plants.

DEPARTMENT OF ECONOMICS

Prof. R.Harieyer alA cost benefit analysis for the purpose of choosingbetween nuclear-powered and coal-fired powerstations.

DEPARTMENT OF MEDICINE

Dr. W. HiftContinuation of work on vitamin B,2 bindingcapacity and related subjects.

DEPARTMENT OFPHARMACOLOGY

Dr. W. P. P. LearyContinuation of studies on the metabolism of (hedecapeptides and octapeptides of angiotensin inman and animals.

DEPARTMENT OF PHYSICS

Dr. M. A. HellbergContinuation of the production of a highly ionisedquiescent alkali plasma and the measurement ofits properties in electric and magnetic fields.

DEPARTMENT OFPHYSIOLOGY

Prof. J.V. O.Reid •Continuation of the measurement of the rate ofprotein synthesis by rat heart in control and trypto-phan-deficicnt animals, and the identification of theprotciiMs). if any. for which tryptophan is found tobe rate-limiting, as well as the initiation of attemptsto measure the coronary flow in rats in vivo.

DEPARTMENT OF SURGERY

Prof. L.W. Baker et el .Pulmonary, embolism as a cause of death is un-common in (he Non-White population as comparedwith the While population. Thrombosis in the calfmuscle sinuses was however unsuspectedry high inthe Non-White population (Kallichurum, 1969)when specifically sought at post mortem. These factsindicate an anomaly, and it is considered to behighly desirable to assess the incidence of thrombosis

. in the Non-White, population following routine sur-gery. "*f fibrinogen is an accurate method of deter-mining, lower leg venous thrombosis. Whether or}-not a high incidence of thrombosis in the calf veinsis found, it,wouW be necessary to investigate thepresence or absence of ileo-fcmoral (thigh and pelvis)thrombosis by means or an ultra sound flow meterand radiology.' When the difference in incidence inthe White and Non-White population has been de-fined, the reasons for the difference could beinvestigated and this may lead to methods by which -'

. this condition could be reasonably reduced in apopulation at risk. - ~ . ,. - " '

UNIVERSITY OF THEORANGE FREE STATE

DEPARTMENT OF BOTANY

Dr.J.N. EloffThe metabolism of South African algae. Phase 1:The physiology and biochemistry- of Micnxysiis.a toxic alga. The following aspects are covered :(a) Determination of the effect of external factors

on toxicily.(b) Characterisation of the toxin.(c) Biosynthesis of the toxin.(d) Investigation of the metabolic difference between

toxic and non-toxic lines of Microcvstis.

Prof. E. M. van Zinderen Bakker et al (Limno-logical Research Group)Continuation of an investigation of the adsorp-tion of the minerals, especially trace elements,in the silt of (he Orange River water.

DEPARTMENT OF ZOOLOGY

Mr.D.J.Kok(a) Continuation of the project concerning the

effect of ionising radiation on the early develop-ment stages of Xenopus laevis.

(b) New project on the radiation effect of erythrositesofXenopuslaevis.

(c) New project on the radiation effect of chromo-somes of Xenopus laevis.

UNIVERSITY OFPOTCHEFSTROOM FORCHE

DEPARTMENT OF CHEMISTRY

Prof. J. A. van den Berg et alContinuation of the kinetic investigation of (fiereactions of transition metal complexes of oxalicacid, malonic acid and other dibasic acids, with theaid of "C.

DEPARTMENT OF PHYSICSANDAEB

Prof. M. A. Meyer, Dr. C. Hofmeyr and Mr. B. CWinkfcrContinuation of a study of nuclear spectroscopywith the aid of <n, y) reactions with reactor neutrons.

Prof. M. A. Meyer and Dr. D. ReitmannContinuation of a study of nuclear spectroscopyby means of p̂ anda-reactions.

DEPARTMENT OFPHYSIOLOGY ANDBIOCHEMICAL RESEARCH

Dr.C.J. Reinecke -Continuation of the following projects: . . :<a) Effect of gamma rays on £. «ft'ribosomê.(b) In vitro translation of plant virus RNS.(c) Participation of 30S. 50S and 70S ribosomes in,

p r o t e i n s y n t h e s i s in vitro.. ;•'--.-•

Mr. J.D. van der Walt '••'•, .An investigation into the protein biosynthesisactivity<MC leusine inclusion) and Ca*T transport "in thecardiac muscle during quick-sickness.

Snail Research Group oftheCSIR and othersContinuation of the following projects: '<a) Ion and osmo-regulattoh of selected South,

African fresh-water snail species,(b). A study of food intake and fond chains in

. connection with soil organisms in South Africa. •(c) Productivity studies on fresh-water organisms.<d) Determination of impact of pollution on large „' quantities of water. ' , \ .,«'.= ' "

UNIVERSITY OF PRETORIA

DEPARTMENT OFELECTRICAL ENGINEERING

Prof. F. G. Heymann el alTheoretical and experimental investigation into theoptimal control of processes, paying special attentionto the optimal control of nuclear power stations.

Prof. L. van BiljonContinuation of an investigation of the shortswitching times which can be obtained with tran-sistors in the avalanche region.

DEPARTMENT OFMECHANICAL ENGINEERING

ProtJ. Visser(a ) Study of the effect of shock waves on the thermal

resistance at the contact area in a compoundmaterial,

(b) Study of the heat transfer in fin tube heatexchangers, with reference to the influence ofthe blanket-to-tube diameter ratio.

DEPARTMENT OFORGANIC CHEMISTRY

Dr. A. WiechersContinuation of the following projects:(a) The quantitative determination of carcinogenic

nitrosamines in tobacco and nutrients by meansof isotope dilution.

(b) The biosynthesis of natural products, in particularthat of alkaloids.

DEPARTMENT OF PHYSICS

Prof.J.G.KoenDetermination of the transfer function of the zero-capacity heterogeneous assembly of natural uraniumand light-water facility al V.P.

RHODES UNIVERSITY

FRESH WATER FISHPHYSIOLOGY RESEARCH GROUP

Prof. B. R. AllansonA study of water and salt fluxes in Tikpiamossambkawhen exposed to I I°C in fresh water and sea waterdiluted, to give Na+ concentration of 5 parts perthousand.

UNIVERSITY OFSTELLENBOSCH

DEPARTMENT OF CHEMISTRY

Continuation and extension of the project: Theextraction of McKVI) from the. H2SO„ medium bymeans of long-chain aminesr . . .

DEPARTMENT OF INTERNALMEDICINEDr. A. Lochnerrta/ - . : . , '".'investigation of the causal öctorts) in the develop-mcni of rhyocardiopathy and muscle dystrophy ofthe Syrian hamster : • ..V :'. .-(a) Characteristics of the DNS in prematurely bont

•hamsters. ' :. *-.,(b) Characterisiics of the transfer systems of generic

. -codes . . . . -_'' 'l' . / """."'."--' •-- • ' '''•;(c> Protein synthesis on. the ribosomes and factors

"'-' effecting polyribosome formation. -'•",'- '"„•

DEPARTMENT OFMECHANICAL ENGINEERING

Prof. D.G. Kroger rt a/Heat mass and momentum transfer in liquid metals.

DEPARTMENT OFPHARMACOLOGY

Prof. A. van ZylContinuation of studies on the mechanism of TSHaction.

UNIVERSITY OF THEWITWATERSRAND

DEPARTMENT OF ANATOMY

Mrs.E. M.VeensfriContinuation of the following project: The proven-tricular exocrine cells of the pigeon are said to per-form a dual function, i.e. they produce hydrochloricacid like the mammalian parietal cells and alsosecrete a digestive enzyme like the chief cells of themammalian gastric mucosa, evidence for the secondfunction being the presence of dense granules withinthe cytoplasm. If these granules are of a secretorynature and akin to the pepsinogen granules of themammalian chief cell, it is argued that leucinewould be taken up by the proventricular cell andincorporated into the granule.

DEPARTMENT QF ANATOMYAND ZOOLOGY

Dr. V. Gabie and Dr. A. AndrewContinuation of an investigation into the inter-relationships between protein synthesis and RNAsynthesis, hormones and histones in cell differentia-tion.

DEPARTMENT OF CHEMISTRYAND BIOCHEMISTRY

Dr.J.B. i^alinskyContinuation of the regulation of enzymes ofnitrogen meubolism.

DEPARTMENT OF DENTISTRY

Dr. D. H. Relief and Dr. P. E. Cleaton-Jones(CSIR Dental Research Unit)Continuation of the analysis of trace elements ofbiological media by means of neutron activation andhigh resolution gamma spectromeuy.

DEPARTMENT OF GENERALPHYSIOLOGY

Prof. C. P. luck . - , = "--'A marked increase in load lifting capacity occursin human muscle within six hours of à singlemuscular contraction. An attempt will be made totrace a metabolic link between this contraction and

. the resulting increase in work capacity. .

DEPARTMENT OF MEDICINE

ProtT.H.BqthwéU:_ •Continuation, of studies'on various aspects of ironmetabolism, with special reference to the patholo-gical sequelae of iron overload. -

Dr.B.GoWberf.<RenalUniO -Alterations in water, electrolyte and acid-basestatus are known to occur in people living at highaltitude, and the purpose of the study is to determine "some of the physiological factors which may accountfor t h e s e . •>'. " - "••. .""- . '•••'•,'. . ~

DEPARTMENT OFORTHOPAEDIC SURGERYDr. M. B. E. SweetContinuation of the study of chondrocyte metabolismin relation to the site of origin of these cells and thecomposition of their matrix. The matrix will bedegraded by chemical or physical means and theresponse of the cells ascertained.

DEPARTMENT OF PATHOLOGYDr. D. MendelsohnContinuation of the elucidation of the sequenceand detailed mechanisms of the stages in the con-version of cholesterol to bile acids in mammalianliver.

DEPARTMENT OF PHYSICSDr. D. S. McLachlan and Dr. F. R. L. SchöningContinuation of a study of the thermal conductivityof the type Ha and lib diamond down to tempera-tures x 0,2°K after 0,7 MeV electron irradiation.

Prof. J. P. F. Sellschop and Dr. B. Th. Verdagen(Nuclear physics Research Unit)The determination of tritium in atmospheric watervapour and rainwater samples.

Prof. J. P. F. Sellschop (Nuclear Physics ResearchUnit)Continuation of an investigation of the applicabilityof neutron activation analysis of geochemical studies.

Dr. E. C. H. SilkContinuation of the study of the effect of irradiationon the internal friction of metals.

DEPARTMENT OFRADIATION THERAPYDr. M. Colman (Overseas iraining/visit: Bursary)Post-graduate study in nuclear medicine.

DEPARTMENT OF SURGERYDr. H. H. Lawson et al (Gastro-intestinal ResearchGroup»A clinical and experimental investigation of thephysiology and pathology of the oesophagus andstomach.

NATAL INSTITUTE FORIMMUNOLOGYDr. B. G. Grobbelaar el alA. Human studies

1. Preparation of human HL-A typing reagents.2. Production of anti-human antilymphocyte

serum, using various antigens.3. In vivo testing of anti-human antilymphocyte

sera.4. In vitro testing of antilymphocyte sera.5. Studies of human lymphocytes.

B. Primate studies :6. ALG research. -7. Preparation ' ' of specific immunoglobulin

reagents. ' , .8. A study of the transplantation antigens of

. baboons and monkeys,, and .the preparation ofspecific tissue typing reagents.

9. Experimental transplantation in the vervet~ monkey. s . ;

:, -: ' .

SOUTH AFRICAN INSTITUTEFOR MEDICAL RESEARCH

CARDIOVASCULAR RESEARCHAND LIVER FUNCTION UNIT

Df.D.Balinsky .- - : ; ':'\' .Continuation of a Study of the active site of enzymesby chemical' reaction with radioactive isotopes andIn combination with labelled substrates.:_- .

ELECTROLYTE ANDMETABOLIC RESEARCH ANDHUMAN BIOCHEMICALGENETICS UNITS

Dr. R. E. BernsteinContinuation of isotopic studies on red cell meta-bolism including the following:(a) A study of the processes involved in the matu-

ration of reticulocytes and in the in vivo ageingof red cells, by means of various methods for thedifferential separation of different means agepopulations of red 'cells, using MFc and "Cr asmarkers.

(b) A study of the intracorpuscular impairment oferythrocyte integrity in hacmolytic anaemias.

(c) A study of inherited metabolic errors by isotopicstudies on red cells.

Dr. R.E.BernsteinContinuation of isotopic studies on mineral andgeneral metabolism:(a) Study of the mechanism of enhancement and

inhibition of electrolyte exchange in cells bykinetic studies with radioisotopes.

(b) Studies on magnesium metabolism, using "Mg(should this isotope become available).

(c> Studies of the binding of "*I- and "U-triiodo-thyronine and thyroxine to serum proteins invitro.

(dt Studies of the incorporation of "Se intostructural protein, with a view to examiningwhite and red cell survival, platelet survival andincorporation into haemoglobin in normal sub-jects and haematological cases.

(e) Radioisolopic assay for digoxin and othercardiac glycosides.

HAEMATOLOGYANDRADIOISOTOPEDEPARTMENTS

Dr. J.MetzContinuation of:(a) A comparative study of porphyrin production

and movement across red cell membranes indifferent species.

(b) The uptake of delta amino laevulic acid (ALA)by paniculate fractions from brain.

POLIOMYELITIS RESEARCHFOUNDATION

Dr. Mary C. Salkinder (Virus Cancer Research Unit)Continuation of the following projects:(a) An estimation of immune response to autoch-

thonous tumours.<b) An estimation of antibody litres to oval and

histocompatibility antigens.

Dr. M. P. Weinbren < Arbovirus Unit)Continuation of the following projects:(a) To develop and put into use an efficient method

for tagging mosquitoes in epidcmiologicalstudies.

(b) The adaptation of the radioisotope precipitationtest to use in local circumstances.

(c) A study of the replication sites and route ofmigration of viruses in infected mosquitoes.

Dr. J. M. VVhitcult (Virus Cancer Research Unit)Continuation of a study of the biochemical basisof malignant transformation using' radiocracertechniques. .

53

NUCLEAR POWER COMMITTEE

APPENDIX A Chairman:

Vice-Chairman:

Members:

COMMITTEES OF THE BOARDDURING 1971

Mr. S. Craib

Dr. J. P.B.Hugo

Dr. F.L. ClarkMr. J.R. ColleyDr. R. K. DutkiewiczDr. W.L. GrantMr. M.C.W. MorrisMr.J. O.TattersallDr. N. TroostMr. N. T. van der WaltMr. R. van der WaltDr.J. N.vanNiekerk

NATIONAL COMMITTEE OF CONTROLOVER RADIOACTIVE WASTE DISPOSAL

LIFE SCIENCES COMMITTEE

Chairman:

Vice-Chairman:

Members:

Dr. C. R. Jansen

Prof. T. Fichardt

Dr.J. K. BassonProf.T.H.BothwellDr.J.S.GearProf. B. C. JansenDr. P. G. MaraisProf. C.J. B. MullerProf. J. V. O. ReidProf. S.J. SaundersProf. P. J. SchoemanProf. I. W. SimsonDr. E. R. SteynDr. P. N. SwanepoelDr. Nancy van Schaik

Chairman:

Vice-Chairman:

Members:

Dr. J. K. Basson

Mr. D. van As

Dr. A. T. B. H. BodenstabDr. C. B. CoetzeeProf. T. FichardtDr. C. R. JansenMr.W.C.S. LeggeDr. P. G. MaraisDr.W.R.McMurrayMr.W.D.OliffDr. E. R. SteynDr. P. N. SwanepoelMr. H. J. van der WesthuizenMr. G. P. Verster

ISOTOPE AND RADIATIONCOMMITTEE

Chairman:

Vice-Chaïrman:

Members:

Dr.J. K. Basson

Dr. R. A. Basson

Dr. R. K. DutkiewiczMr. W.C. S. LeggeDr.J. D. LouwMr. G. A. P. LowDr. P. G. MaraifDr.W.R-McMurrayMr. A. C, H. OttoDr. W. L. RautenbachMr. B. G RussellDr. L. H. SteinDr.J. N.vanNiekerkDr. J. van R. Smit

MARKETING COMMITTEE

Chairman:

Members:

Mr.T.L.Gibbs

Dr.D.J.HverettMr.H.J.P.L-KrugerMr. G. A. MacmillanDr. R. E. RobinsonMr.À.J.F.ViljoenMr.M.P.WesselsMr.R.E.Worroll

PATENTS COMMITTEE (INTERNAL)

Chairman : Dr. J. P. B. Hugo

Vice-Chairman:

Members:

Dr. R. S. Loubser (Tö 31stMarch, 1971)

Mr. D. Lion-Cachet(To 31st March, 1971)Adv.H.T.J.NaudéDr. N. P. PienaarDr. R. E. RobinsonMr. R. van der Walt

RESEARCH GRANTS COMMITTEE

Chairman: Dr. L. Alberts

Members: Prof. F. G. HeymannDr. C. R. JansenDr, J.F. KempProf. W.L. MoutonProf. P. H. StokerDr. S. J. P. K. van HeerdenProf.P.WedepohlProf. E. X Wpodbum

COMMITTEE ON URANIUM RESERVES

Chairman: ';• Dr. J.W. von Backström

Members: Mr.J. BemingMr. Â. C. HaasbroekDr! R. E. RobinsonDr. J. J. SchoemanDr.H.C.M.Whiteside

54

I. PELINDABA REPORTS

LIST OF PUBUCATION8 BY STAFFMEMBERS AND BURSARS* OF THEBOARD

ittt hmwuf tfct *—å

PEL.208: MÖLLER. C: Slabber, J. F. M.: Brown. K. T. Addendum to theengineering and safeguards report on SAFARI-1 for 20 MW

.. operation.

PEL209: BASSON. J. K.: Wyndham. C. H.; Heyns. A. J. A.; Kcclcy. W. H.;Barnard. C. P. S.; Munro, A. A.; Webster, 1. Luns cancer and expo-sure to radon daughters in South African gold/uranium mines.

PEL210: MAUNDERS. E. J.; Ernst. A. PELINOM1C II-A computer pro-gramme for caluclating nuclear power cost.

PEL21J: ATOMIC ENERGY BOAKD. Advanced reactor types of potentialfuture interest to South Africa.

PEL213: VAN AS. D. PELSHIE-A general purpose shielding programmefor point and extended gam ma-ray sources.

PEL214: VAN DER WESTHUIZEN, M.; Smith. M. J. The change in concen-tration of tritium in water during evaporation and the possibilityof using ' it to determine evaporation from water, soil and plantsurfaces.

PEL216: VAN AS. D.: Vleggaar. C. M. Environmental radioactivity at theNational Nuclear Research Centre, Pelindaba. Report for (he year1970.

PEL 217: DU PLESS1S. T. A. The radiation-induced copolymerizalion ofchlorotrifluoroethylene with ethyl vinyl ether.

PEL2I8: DU PLESSIS. T. A. The radiation-induced ionic polymerization ofiso-butyl vinyl ether in bulk and in solution.

II. PUBLICATIONS

ACKERMAN. L. G. J.: Basson, R. A. Application of mass spectral data to theradiolysis of aliphatic alcohols. Pan II. l-butanol. J. S. Afr. Chem. lust.( 1970) v. 23 p. 154.

ADRIAN. H. W. W.; Kruger. J. Testing the fillers of the clean-air booth. Heating.Air Conditioning and Refrigeration (1970) v. 3 p. 31-39.

ALLEN, S.: Cooper, G. A.: Johnson, D. J.; Mayer. R. M. Carbon fibres of highmodulus. Proceedings of the Third Conference on Carbon and Graphite,London, 1970. Society Chemical Industry, p. 456-462.

APPELBAUM, P. d Hugo, N.: Coelzee, J. N. A flagellar phage for the Proteus-providemegroup.J.Gen.ViroU\97l)v. 13p. 153-162.

BARNARD. E.: Coetzee. N. ; De Villiers. J. A.M.: Reitmann, D. : Van der Même. P.The low-lying states of 1 n l from the <n,n'y) reaction. Z. Phys. (1971) v. 243p. 121-125.

BARNARD. E.: De Villiers. J. A. M.: Engelbrtcht. C. A.; Reitmann. D. The levelstructureofÎKAu.«Hc/./>A^s.(l97I)v. 167 A p. 511-528.

BARNARD. E.; De Villiers. J. A. M.: Reitmann, D.; Tepel. J. W. InteMctions offast neutrons with *Sc. 2. Phys. (1971) v.245 p. 36-44.

BARNARD. E.: Coetzee. N.. De Villiers. J. A. M.: Reitmann. D.: VenderMerwe. P.The energy levels of "'Sb and 1MSb isotopes from (n,n>) reactions. Nud.Phys. ( 1971 ) v. 172 A p. 215-224.

BARNARD. E.: De Villiers, J. A. M.: Cxnet. N.: Reitmann. D.;VanderMerwe. P.The energy levels of "Br and "Br. Z. Phys. ( 1971 ) v. 246 p. 424-430.

BASSON. R. A. The radiation chemistry of the hydroxyl group. Chemistry ofthe Hydroxyl Group. Ed. S. Patai. Wiley, London, 1970.

BASSON, K. A.: Van Wyk. L The radiolysis of etrunol-ethylenc systems. Part I..Tclomerisation reactions M low pressures. J. Chem. Soc. B ( 1971 ) p. 809-813.

BASSON, R. A. Radiation methods of polymerisation. 5. Afr. Chem. and Eng. Age(Dec 1970) v. 7.

BASSON, K. A. Radiation. 5. Afr. Pherm. J. (May 1971 ).

COOPER, G. A.; Mtytr. R. M. The strength of carbon libres. J. Muter. ScHV>l\); « M 7

DE BKUIN. E. j . P.: Bitter, E. I/.; Hoog, J. M. C; Van Rooyen. R. J. Radki-i l k b U C t f r U m » v . 13(«>p. 109-115.

DE BKUIN. E. J. t.: Meyer, B. J. InwUn Mention ia Banni with skkroiis orhepMoma. 5. Afr. Mté. J. (Au» 1*71 ) v. 4» p. **!•***.

DE HAAS, K. S. Détermination of activity coefficients of tMocyank acid and«idBt-ouc elects in a mixture of efcctmlytes front extraction data.J. Chem. EHf. DtU ( I »71 ) v. l«4> p. 457-45».

DE HAAS. K. S.; Brink. P. A.: Cnwthtr, f. Solvent: extraction of iron,cobakmå nickel from tWocyanale rucks. J. ltmf. Nuet. Chtm. <l»7Uv. 33 p.43OI-

DE WET. W.J. Trace etememary. my dear Watson'. Nuit. Mire (M 1971) p. 20.

%1 »' ,. si -S -

DU PLESSIS. P. de V. On the magnetization dependence of the magnctocrystal-line anisotropy of iron. J. Phys. Chem: Solid St. Phys. <197I) v. 32 p. I 691-1696.

DU PLESSIS. P. de V.; Viljoen, P. E.; Alberts, L. Anomalies in the magncto-strictionofiran.J.P/iyj.F..AJ««/P/iyj.(1971)v. 1 p.328-333.

DU PLESSIS. P. de V.: Van Tonder, S. J.; Alberts, L. Elastic constants of aNiO single crystal: I. J. Phys. Chem.: Solid St. Phys. (1971) v.4p. 1 983-1 987.

DU PLESSIS. P. Je V.; Van Tonder. S. J.; Alterts. L. Magnetostriction of a NiOsingle crystal: II. J. Phys. Chem. : Solid St. Phys. ( 1971 ) v. 4 p. 2 565-2 571.

DU PLESSIS. P. de V. The paramagnetic susceptibility of the ferrite FeV,O«.J. Phys. Chem.: Solid St. Phys. <197l)v.4 p.2 919-2 922.

ENGELBRECHT. C. A. Recipes for multiple scattering corrections. Nucl.Instrum. Methods ( 1971 ) v. 93 p. 103 -107.

ENGELBRECHT. C. A. From quark to quasar. Spectrum < 1970) v. 8 p. 532-534.

F0UCHÉ. K. F. Extraction of perrhenatc and penechnetate with N-benzyl-N-phenylhydroxylamine.J. inorg.Nucl. ChemA\97\)v. 33 p.867.

HANKES. L. V.'; Leklem, J. E.; Brown. R. R.; Mekel. R. C. P. M. Tryptophan:Abnormal metabolism in Pellagra patients. Preliminary Report. Melab.(Jun 1970) v. I9<6).

HANKES. L. V.': Lekiem, J. E.; Brown, R. R.; Mekel, R. C. P. M. Tryptophanmetabolism in patients with Pellagra: Problem of Vit. B, enzyme activityand feedback control of tryptophan pyrrolase enzyme. Amer. J. Clin. Nutrit.(Jun 1971 ) v. 24 p. 730-739.

HEISS. W. D. An effective single-panicle potential. Nucl. Phys. (1971) v. 169Ap. 248.

HENNING. J. J.: Wolf, W. Positive definite particle densities for the positivefrequency solutions of the Klein Gordon equation with arbitrary mass.Z./>*yj.(l97l>v.242p. 12.

ISEBECK. K. Low temperature research on radiation damage. Nucl. Active(Jan 1971) p. 27.

JAC0BSEN. R. A. Estimating the number of ion pairs produced in a gas by anelectron of initial energy below I keV. Plasma Phys. (1971) v. U p. 525-528.

JOOSTE. S. V. Effects of antilymphocyte serum on hyperacute renal rejectionin goats. S.Aft.Med.J. (1971) v. 45(16) p. 439440.

JORD AAN. J. H. ; Smedley. S. Synthesis of branched-chain amino sugars via aspiro-epoxide derivative of 2-amino-2-deoxy-D-glucose. Carbohyd. Res.(1971) v. 16 p. 177-183.

JORDAAN. J. H.: Smedley. S. Synthesis and hydroboration of a 3-C-methylenederivative of 2-amino-2-deoxy-D-glucose. Carbohyd. Res. (1971) v. 18p. 303-309.

LEKLEM, J. E.: Brown, R. R.: Hankes. L. V. *; Jansen. C. R. In vivo formation ofthe 8-methyl ether of xanthuric acid in man. Proc. Amer. Assn. Cancer Res.( 1971 )v. 12(22).

LIPPINCOTT, S. E.: Baker, C; Jansen. C. R. Experimental radiation therapy bydeuteron bombardment of a transplanted neoplasm in mice. Radiât. Res.(I971)v.47(l).

LOV ELL. G. H. B.: Perels. D. R.: Brin. E.J. Preparation of the monophosphidesand monochalcogenides of uranium and thorium by the volatile metal pro-cess. J. Nucl. Mater. ( 1971 ) v. 39(3 ) p. 303-310.

MAUNDERS. F. J. Window shopping for power reactors. Nucl. Active Ov\ 1971)p. 7.

MAYER. R. M.: Morris. E. T. Observation of voids in irradiated aluminium.Proceedings of Symposium S63 of the South African Electron MicroscopySociety. CSIR, Pretoria, 1971.

MEYER, B. J.; Van der Merwe, M.; Du Plessis, D. G.; De Bruin. E. J. P.:Meyer, A. G Some physiological effects of a mainly fruit diet in man.S.Afr. Med:JAFeb 1971) v. 54(8) p. 191-195.

MEYER, B J.; De Bruin. E. J. P.: Du Plessis, D. G.; Van der Merwe, M.; Meyer,A. C. Some biochemical effects of a mainly fruit diet in man. 5. Afr. Med. J.(Mar 1971) v.45(IO)p. 253-261.

NAUDÉ. H. T. J. Of ships and sealing wax. Nucl. Active (Jan 1971 ) p. 22.

NEWBY-FRASER. A. R. Medical cross-section. Nucl. Active (Jan 1971 ) p. 4.

P1NEO, W. F. E.; Bilpuch, E. G.; Newson. H. W.; Malan. J. G. High resolutionneutron total cross-section measurements of "*Sr. Bull. Amer. Phys. Soc.(I97t)v.l6p.495.

PRINSLOO. J. G.: De Bruin. E. J. P.: Uubscher, N.; Venter, L. M.; Kruger, H.Comparison of oral glucose-tolerance tests and serum insulin responses inPellagra and Kwashiorkor. 5. Afr. Med. J. (May 1971 ) v. 45(20) p. 554-555,

PURVES. L. K.: Bersohn, 1.; Geddes, E. W. Serum alpha-feto-protein and primarylrvercancerinman.Ci:iMrr(l970)v.25p. 1 261-1 270.

PURVES. L. *.,- Van der Merwe, E.; Bersohn, 1. Serum alpha-feto-protein. V.The bulk preparation and some properties of alpha-fcto-protein obtainedfrom patients with primary cancer of the liver. S. Afr. Med. J. (1970) v. 44p. 1264-1 It*.

PURVES. I. Jr.; Van der Merwe, E.: Bersohn, I. Variants of a-feto-protcin.Lancet ( l»70) v. 2 p. 464-4*5.

n/RVES. L. K. Surveys for alpha-fao-protein among Bantu gold-miners.Proceedings of a Symposium on Mycoioxins in Human Health, Pretoria.l»70. MacMillan. London, 1*70.

RETIEF. D. H. : CteMon-Jones. P. E.: Turkstrt, J. : De Wet. W. J. The quantitativeanalysis of Sr, Au, Br. Mn and Na in normal human enamel and dentineby neutron activation and high rejotution gamma spectrometry. J. Dem.Ass.S.Afr.t\niiv.2êp.a.

•Or. Haakt*, t mewtfc «raker fn.n arooUwvm Nauoml LakoMttuy, worked in tbrMr Sciem» M V M M hr armai meurt,» Avta* 1*71.

ROUX. A. J. A. Kernenergie en water. S. Afr. J. Sci. (Mar 1971) v. 67(3)p. 177-182.

ROUX. A.J.A. Uranium enrichment. Nucl. Active (Jul 1971 ) p. 2. .

RUCHl, C; Cottier. H.; Cronkite, E. P.; Jansen, C. R.: Rai. K. R. Studiesonlymphocytes. XVII. Differential lymphocyte depletion in lymphoreticularorgans of thé calf during continuous extracorporeal X-radiation of thecirculating blood. Cell Tissue Kwel. (Jul 1970) v. 3(3 ) p. 301 -315.

SELZER. A. Radiation protection and industrial radiography. Founding WeldingProduction Eng.J. (Jan I971)v. 1(1)p.23-29.

SNYMAN. G. C. Nuclear techniques foron-stream analysis of uranium solutionsand slurries. Proceedings of the Australasian Institute o' Mining andMetallurgy. Symposium on Automatic Control Systems ir. Mineral Pro-cessing Plants. Brisbane. May 1971,p. 113-127.

TURKSTRA. J.: Behrens. G. B.: De Wet. W. J. The determination of lanthanum,samarium, europium and thorium impurities in nuclear-grade uraniumproducts. J. S. Afr. Chtm. tnst. (May 1969) v. 22 p. 11 i-120.

TURKSTRA. J.; Smit. H. J.: De Wel. W. J. Non-destructive neutron activationanalysis of six South African standard rock samples utilising high-resolutiongamma spectrometry. J. S.Afr. Chem. Inst. (May 1971)v.24p. 113-125.

URBAN. K.; Seeger. A.** Application of high-voltage electron microscopy toradiation damage studies. Proceedings of Symposium S63 of the SouthAfrican Electron Microscopy Society, CSIR, Pretoria, 1971.

VAN AS. D.: Fourie. H. 0. A comparison of the "Sr content in the bone ofpopulation groups with both high and low calcium diets. USAEC Health andSafety Laboratory. Report .•'42, Apr 1971.

VAN AS. D.: Fourie. H. O. Strontium-90 in the bone of different South Africanpopulation groups. S. Afr. Med. J. (Jun 1971 ) v. 45 p. 694-696.

VAN AS, £>.; Vleggaar. C. M. Determination of an acceptable '"I concentrationin air when the critical intake is through milk. Health. Ph\-.. (Jul 1971) v. 21p. 114-116.

VAN DER LINDE, H. J.: Freeman, G. R. The influence of temperature on ther-radiolysisof isopropyl alcohol vapour. J. Phys. Chem. (1971 ) v. 75 p. 20.

VAN DER LINDE. H. J.: Von Sonntag. C. The U.V. photolysis U=185 nm) ofethylene glycol in aqueous solution. Photochem. and Photobiol. (1971)v. 13 p. 147.

VAN DER MERWE. S.; Hoog, J. M. C. The biosynthesis of L-Arginine inProteus Rcttseri R49. S. Afr. Med. J. < 1971 ) v. 45(21 ) p. 586.

VAN DER SPUY. E. An infinite-component free field carrying compoundslying on a Regge trajectory. Nuovo Cm. A (Jun 1971 ) v. 3(4) p. 822-846.

VAN DER SPUY. E. Observable processes corresponding to a fundamentalReid.NuovoCim.AUun l971)v.3(4)p.847-856.

VAN DER SPUY, E. A non-perturbative solution of a nonlinear field equationof motion. Nuovo Cim. A (Aug 1971 )v. 4(3) p. 647-675.

VAN DER SPUY. E. A fermion-based particle model. Nuovo Cim. A (Sep I97I)v. 5(4) p. 163-183.

VAN DER WALT. C. M. Comments on the paper "Neutron IrradiationDamage in Molybdenum, Part I" by D. M. Mailer and B. L. Eyre. Phil.MagAOct I971)v.24(190)p.999. •

VAN REENEN. T. J.; Van Niekerk. M.; De Wet. W. J. Investigations on tht ion-exchange and ionic transport properties of glass membranes in moltensalts by an electrolytic transport technique. J. Phys. Chem. (1971) v. 75p.2815.

VAN RO0YEN. R. J.: Jansen. C. R.: Meyer. B. J. Pernisieuse anémie by dieBanloe. Geneeskunde U971 )v. 13(3)p.41-53.

III. PAPERS GIVEN AT SCIENTIFICGATHERINGS OF WHICH THEPROCEEDINGS HAVE NOT YET BEENPUBLISHED

South African Chemical Institute. 21st Convention,Gr*ntmslown<February)

ACKERMAN. L. G. J.; Bosson. RA. Stralingschemie van n-butanol.

BASSON. R. A. On the prediction of the radiolytic behaviour of organicmolecules. : .

CR0WTHER. P.: De Hots. K. S. Liquid-liquid extraction using molten salts andorganic liquids at distributing phases.

DE WET. W. J, Theory of membrane potentials of ion selective ekarodes..

FOU Kl E. P. J.; Smkh. M. E. Diveniflkaste van die radloboloopproduksie-piogram te PeUndaba.

••Dr Scrgcr. a mcMck «raket from tbr 1••i r t r — v * m in tin rtniirii r u i i i u m P I

: rtmek hmftinc hl SttMtfMI, spent six

JUXJtIAANSE. A.: Basson. R. A. Stralingsgeïduseerde poltmerisasie vanoppervlaktebedekkings op veselbord.

NEETHLING. A. J.: Crowther. P. Termodinamlese eienskappe van drieledigenatriumlegerings.

STEYN. W. M.; De Wet. W. J. Thermodynamics and applications of ionexchange on glasses.

STRELOW. F. W. E.rToerien. F. v. S.: Weinert. C. H. S. W. Accurate silicaterode analysis based on separation by ion exchange.

TANEWSKI. E. Z. : Basson. R. A. Preparation of wood plastic composites.

THOMAS. A. C: Basson. R. A. High pressure polymérisation of ethyleneunder the influence of radiation.

T0ER1EN. F. v. S.: De Wet, W. J. The separation of the noble metals by ion-exchange'ehromatography.

TURKSTRA, J. ; De Wet. W. J. Outomatiese neutronaktiveringsanalise.

VAN DER LINDE. H. J. r-stralingsgelnduseerde pirolise van 2-propanoldamp.

VAN REENEN. T. J.; De Wet. W. J. Verifikasie van die Eisenman-teorie vanioonsdektiewe elektrodes.

VAN WYK. I.; Basson. R. A. Telomerisasiereaksies in etanol/etileensistemeonder die invloed van straling.

South African Association of Physicists in Medicine and Biology. Annual Congress.Pelindaba (March)

BASSON. J. K. Longkanker en radonblootstelling in Suid-Afrikaanse goud/uraanmyne.

BASSON. R.A. Radiation sterilisation techniques.

DE BEER. G. P. 'a Program vir die berekening van dosistempo's vanaf punt-en uitgebreide gammabronne.

DU PREEZ. M. L. : Basson. J.K.: Van As. D. : Winkkr. B. C Report on the SecondConference of the International Radiation Protection Association, Brighton,1970.

KRUGER. J.: Adrian. H. W. W. Filler tests on a new type of activated charcoalfilter in the emergency ventilation system of SAFARI-1 and on absolutefilters at a clean-air operating theatre.

VAN DER WESTHUIZEN. M. Die voorkoms van tritium in die natuur en diegebruik daarvan en van deuterium as spoorder.

International Conference on liquid Extraction. The Hague. Holland (April)

FOUCHÉ. K. F. : Le Roux, H. J. Solvent extraction of yttrium and the lanthanideswith N-benzoyl-N-phenylhydroxylamine.

Congress of the Society of South African Pathologists. Pretoria (June)

PURVES. L R. ; Putves, M. Radioimmunoassay of alpha-feto-protein.

Tenth Biennial Conference on Carbon and Graphite, Bethlehem. Pennsylvania (June)

MAYER. R. M.; Thrower. P. A. Self diffusion in graphite.

World Energy Conference. Bucharest (June)

MAUNDERS. E. J.: Roode. J. D. An approach to the problem of optimising thelocation of electricity generating plants in South Africa.

South African Institute for Physics. 16th Annual Congress. Cape Town (July)

BARNARD. E.; Coetzee, N.; De ViBiers. J. A. M.; Malan, J. G.; Reitmann. D.:Van der Mente, P. Die navorsingsprogram met die RAK se 3 MeV-versneUer.

BARNARD. E.: Coetzee.-N.;De ViUkï.J. A. M.: Reitmann, D.;VanaerMerwe.P.Onelastiese neutronverstrooiing vanaf Mn.

BARNARD, Ë.: Coetzee. N.: De Vitiers. J. A. M.: Reitmann. D.iVanderMerwe.P.Energy level structures of some stable isotopes from (n,n>) reactions.

COETZEE.. N.; De VUiers.J. A. M.; VanZyl.S. W.J. Rekenaarsu-lsel vir inbaan-- gebruik in kemfisiese eksperimente.

COETZEE. N. • De ViUkrs. J. A.M.: Van Zyl. S. W. J. Kemfisiese dataverwerking' met behulp van'n rekenaarstelsel.

GROSSE, E.; Richter, A.; repel. J. Vf., Resonance holes in doubly forbiddenisospin reactions.

HOFMEYR. C. Die kernstruktuur van «»Ni uit (n.rt-metings.

ISEBECK. K; Poole, K. F. Comparison of the annealing behaviour of Frenkel• defects produced by irradiating Ag, Cu, and Ft with (ast and thermal! neutrons. • . ; •

MALAN; J. G.; Hoeo, W. F. E.; Newjon, H. W.; Bilpuch, E. G. Die totaleneutrondeursnit van "Sr. '

MAYER. R. M. Tranapon properties of irradiated copper.

MAYER. R. M. ; Morris, E. T. Void formation in irradiated aluminium.

WINKLER, B. C ; Hifmeyr. C. 'n Nuwe <n.pMàsliiteit

StmrntrSeries' 'm Thttrttkd Physics, ttk Aitmul Semrntr. Cape Town (July)

ENGELMMCHT. C. A. An anatysii of RFA: Features In the tntpin polarisationapproximation.

HE ISS. W. D. The three-body problem and the Ljp^mano-SchwinacT equation.

HENNING, J. J. Ff-nKMniese atome.

TtnL J. W. Jmaow-komUkt: DiagnannMiete legaleke. ,

VAN P«MBKWE, t. «to T. Uiwatk ciwpoiHt particle».

VILJOEN. J. el P. Ot RXtTW-KtttcHtnilulf M tttUtt:imermim* AmcWm f$r Dmé Unmet, im* Afrkm DhUm: Flfih

TURKSTRA. J. Neutron activation analysis as applied to dental structures.

International Congress on Statistical Properties of Nuclei. All/any. New York (August)

GROSSE, E.; Richter, A.; Tepel. J. W. Search for resonance holes in doublyforbidden isobaric analogue resonance reactions.

International Conference on Thermal Analysis (ICTA III). Davos. Switzerland(August)

SCHAEKERS, J. M. Preparation and thermogravimetric study of neutral uranylphosphate t(UO,),(P04)IJCHjOl.

VAN TETS. A. Uranium oxides under different atmospheric and thermomctricconditions.

Conference on Topics in Polymer Chemistry. Johannesburg (September)

THOMAS. A. C.:Juniaanse.A. Radiation initiation of polymerisation.

Fourth United Nations international Conference on the Peaceful Uses of AtomicEnergy. Geneva. Switzerland (September)

BASSON. J. K.: Wyndham, C. H.; Heyns, A. J. A.; Keeley. W. H.; Barnard,C. P. S.; Munro, A. H.; Webster, I. A biostatistical investigation of lungcancer incidence in South African gold/uranium mines.

BASSON. R. A. Radiation polymerisation of monomer-impregnated SouthAfrican timbers.

HAASBROEK, F. j . The use of radioisotopes and radiation in agriculture inSouth Africa.

TATTERSALL. J, 0.: Simpson, D. M.: Reynolds. R. A. A discussion of nuclearplant safety with reference to other hazards experienced by the community.

TREMEER, G. E. B.; Maunders. E. J. Forecasting the role of nuclear energy inSouth Africa.

YOUNG, S. A. Some aspects of the nuclear fuel cycle and their relationship tothe production of raw materials.

South African Ceramic Society: Symposium on Ceramic Fabrication. Olifants-fontein (September)

LOVELL. G. H. B. Fabrication of ceramic nuclear fuels.

MAYER. R. M. Fabrication of carbon articles.

Symposium on the Future of Nuclear Physics in South Africa. Pretoria (November)

BASSON. J. K. Kerntegnieke in die nywerheid.

DEWET.W.J. Produksie van reaktorisotope.

ENGELBRECHT. C. A. Teoretiese fisika as wetenskap.

VAN DER SPUY. E. Die toekoms van kernfisika in Suid-Afrika as 'n wetenskapten opsigte van deeltjiefisika.

VAN DER WALT. R. Die kemfisikus en kernenergie.

Second Conference of the International Radiological Protection Association, Brighton,Engfand(May 1970)

VAN AS. D. : Fourie. H. O. A comparison of the "Sr content in bone of populationgroups with high and low calcium diets.

VAN AS. D.: Short. R. C: Van derWestUuizen.M. An experimental technique forthe determination of the dispersion of airborne effluent in a complex topo-graphic environment.

Joint Conference of the Chemical Institute of Canada and the American ChemicalSociety. Toronto (May 1970)

VAN DER LINDE. H. J. du T.: Bansal, K. M.; Freeman, G. R. A cattonic chainreaction in the radiation-induced pyrolysis of alcohol vapours.

IAEA Symposium on the Recovery of Uranium from its Ores and Other Sources.Vienna (1970)

FAURE. A.; Tunley. T. H. Uranium recovery by liquid-liquid extraction inSouth Africa.

Chemeca 70 Conference. Sydney and Melbourne. Australia (August 1970)

LOVEDAY. B. K.: Tolmay, A. T. The development of a mathematical model forlarge-scale mills.

Chemical Engineering Symposium. Durban (August 1970)

LOVEDAY. B. K.: Robinson, C. G.; Paynter, J. C. A model for the prediction ofleaching curves and the determination of activation energies in leaching.

IV. THESES

C0IM0RN. R. f. The study of a distribution Me comtint model in predictingthe performance of a phosphate dotation true». D.Sc. thesis, University,of Natal <I970>.

TURKSTRA. J. An InveMifMfcM of simultaneoiM muhltJement analyst» byhlfh resolution gamma »peciroroetrr. PIU>. thesis, UnivenkvorSoMli AWc*

' ,(I»70X , " • ' - /•• . r - ' • • - >

VAN WYK. L Die MnttagKhemiewM die cttnolleie etUeeniJMeem. Ph.D. thesfc,UMvtnttvrf Sowh Africa <im».

•7

J. \ %:. , . •

FINANCES

During the financial year 1970/71, a total amount of R14 098 730 was expended jointly under the Research and AdministrationFunds. Of this amount salaries and administrative costs made up 39,31% and the cost of equipment purchased was 15,83%of thetotal expenditure. The corresponding percentages for the 1969/70 financial year were 43,52% and 12,84% respectively.

As will appear from the statement hereunder, which is a summary of expenditure under the two funds mentioned, salaries andadministrative costs for the past twelve years ending 31st March, 1971 amounted to 36,58% ofthe total expenditure, compared with35,60% as at 31st March, 1970. Current expenditure also increased from 12,41% of the total expenditure as at 31st March, 1970 to13,84% as at 31st March, 1971, while expenditure in respect of capital works has decreased from 27,64% ofthe total expenditure asat 31st March 1970 to 26,08% as at 31st March, 1971. The ratio ofthe other items of expenditure to total expenditure shows nosignificant change.

Summary of total sxptridltur* under th* Rsssarch and Administrativ* Funds for th» period1st April, 1959 to 31st March, 1971

Period

Nature of Expenditure

Capital Works . . . . : . . . .

Equipment

R u n n i n g expenses

Salaries a n d A d m i n i s t r a t i o n . .

Subs id ised research . . . . . .

Training cos ts . . . . . . . . .

Bursaries

Library

Total

1/4/1959 to31/3/1964

R5 135 945

681311 |

443 190 !

1934 680 !i

595 053 j

502 394 !

228054

49 391

9 570018

8 612 246

7 779 63 Ï

20 577483

2 882117

944991

515696

271942

56 255 508

--«*.-*vs*

•«t!*" -i

»•«,,

lis 14,118.15

85,626.4010 $00:0090,776.0857:233.51

36,444.77

i.

ATOMIC ENEMY BOARD

»CONSOLIDATED BALANCE SHEET

LIABILITIES

Capital AccountInterest on handLoan from TreasurySundry creditorsFunds

m-

The above sectionj F p56 of ̂ tite Exchequer and Audit Act i & 2Ï of »56= » amended, »r&«d with secüon1$W of theijtomfc Enetw ActNo. ^>of 19^7, and (»mrópttlon ft has been drawn

**~mr*t.-

-- <y

asat 31st Match,.1971

(Compiled in terms of section 18 of Act 90 of 1967)

ASSETS â'

FixedAssetsEquipmentLibrary and filmsInvestmentStock.SundrydebtorsBankbalanceSundries

14654180,54

:; ,21703435:

Cj2«7 060,16 .

t l

the Consolidated Revenue Fund andyear. ' ' ^ . -t.. . ,'. , . ..*

ROUX!t

#-*J% :i

'•^f' ' >»s*ii

ÄM^

ATOMIC ENERGY BOARD

ADMINISTRATION ACCOUNT(Compikdintermsofseaionl8ofAa?OofI967)

I i

EXPENDITURE

pp

| | |

Salaries, wages and allowancesSubsistence and travelling expensesPostal and telegraph servicesPublications and booksExhibitionsRadioactive isotopesAdministration expensesEquipment

• Library ;Contribution to International AtomicEnergy Agency :

- Royalty paymentsContribution to research fundTritium analysisSundrydebtorsRevenue paid over to Consolidated Revenue Fund

[SEARCH FUND

kcwnpflfd»! JCTjrwo/smäw 18ofAct£p.ofl967)'

REVENUE AND EXPENDiTURE ACCOUNT

for the financial year ended 31 March1971

REVENUE

Government funds .Radioactive isotopesSundry revenue . .Royalties

- °ô ..

10 179221,7151 29433

30*251,71

ijl

* v

»SJS 399.06

T. A. VENTERHead: Finance

%^

- C v;6' !

CONTRIBUTORS TO THE 1970/71 RESEARCH PROGRAMME

Apart from the funds made available by the State for administration and research, financial contributions to theResearch Programme 1970/71 were made by the following private organisations:

1. THE ELECTRICITY SUPPLY COMMISSION.2. NUCLEAR FUELS CORPORATION OF S.A. (PTY) LTD.3. THE ROBERTS CONSTRUCTION COMPANY LIMITED.

Deuterium nuclei are subjected to gantmaray irradiation as part of theproject to determine underground waterflow.

This Fifteenth Annual Report is published by theATOMIC ENERGY BOARD, Private Bag X256, Pretoria.

Compiled and designed by the External Relations Divisionof the Board and printed by Hortors Printers, Johannesburg.

ISBN 0 86960 147 4