Understanding neutron radiography reading vii nrhb part 2 of 2

Understanding Neutron RadiographyReading VII-NRHB Part 2 of 2Principles And Practice Of Neutron RadiographyMy ASNT Level III, Pre-Exam Preparatory Self Study Notes 21 July 2015

Charlie Chong/ Fion Zhang


Nuclear Power Reactorsapplications









Charlie C

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Charlie C

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The Magical Book of Neutron Radiography




ASNT Certification GuideNDT Level III / PdM Level IIINR - Neutron Radiographic TestingLength: 4 hours Questions: 135

1. Principles/Theory• Nature of penetrating radiation• Interaction between penetrating radiation and matter• Neutron radiography imaging• Radiometry

2. Equipment/Materials• Sources of neutrons• Radiation detectors• Non-imaging devices


• Electron emission radiography• Micro-radiography• Laminography (tomography)• Control of diffraction effects• Panoramic exposures• Gaging• Real time imaging• Image analysis techniques

3. Techniques/Calibrations• Blocking and filtering• Multifilm technique• Enlargement and projection• Stereoradiography• Triangulation methods• Autoradiography• Flash Radiography• In-motion radiography• Fluoroscopy


4. Interpretation/Evaluation• Image-object relationships• Material considerations• Codes, standards, and specifications

5. Procedures• Imaging considerations• Film processing• Viewing of radiographs• Judging radiographic quality

6. Safety and Health• Exposure hazards• Methods of controlling radiation exposure• Operation and emergency procedures

Reference Catalog NumberNDT Handbook, Third Edition: Volume 4,Radiographic Testing 144ASM Handbook Vol. 17, NDE and QC 105


Fion Zhang at Shanghai21th July 2015

http://meilishouxihu.blog.163.com/


Greek Alphabet


Charlie Chong/ Fion Zhang http://greekhouseoffonts.com/



Quantum Mechanics Part 3 of 4 - The Electron Shells

■ Film Series: https://www.youtube.com/watch?v=Q9Sl1PYSyOw

https://www.youtube.com/watch?v=Q9Sl1PYSyOw


How to make Neutrons - Backstage Science

■ https://www.youtube.com/embed/jhlZaWGFQZY

https://www.youtube.com/watch?v=jhlZaWGFQZY


Neutron Radiography

■ https://www.youtube.com/embed/uEX1fqSEq9I

https://www.youtube.com/watch?v=uEX1fqSEq9I&list=PLNpr_5ZJjWtM5WE_bC8vnN4kyGpZIE6AN


Neutron radiography of dynamics of solid inclusions in liquid metal

■ https://www.youtube.com/embed/HzbV6q2B0Q8

https://www.youtube.com/watch?v=HzbV6q2B0Q8&list=PLNpr_5ZJjWtM5WE_bC8vnN4kyGpZIE6AN&index=2


2. RECOMMENDED PRACTICE FOR THENEUTRON RADIOGRAPHY OF NUCLEAR FUEL

a) This part of the Neutron Radiography Handbook is a guide for thesatisfactory neutron radiographic testing of nuclear fuel. It relates to the use of (1) photographic film, (2) radiographic film and (3) tracketch recording materials.

b) It includes statements about prefered practice but does not discuss thetechnical background which justifies the preference. Such backgroundinformation is given in Part 1 of the Handbook.

c) This document does not recommend a prefered design for the equipmentwhich produces the neutron radiographic beam, or the prefered quality of the beam (neutron energy, gamma contamination etc.). For this data reference should be made to the neutron radiographic principles discussed in Part 1 of this Handbook.


d) This document describes methods of measuring radiographic quality andrefers to reference radiographs for nuclear fuel, but it does not cover theinterpretation or acceptance standards to be applied as this is considered to be a subject that should be covered by the Order Specification and therefore a matter of contractual agreement between the supplier and the purchaser.

e) The numerical data quoted herein has been taken from Part 1 of theHandbook, which gives the relevants source references.

f) Sections 2.7, 2.8, 2.9, 2.11 and 2.12 of this Recommended Practices havebeen taken verbatim 一字不差的 from ASTM E94-77 'Standard Recommended Practice for Radiographic Testing' and the compilers of this Handbook make grateful acknowledgement to the American Society for Testing Materials for their permission to do this.


2.1 APPLICABLE DOCUMENTSa) Neutron Radiography Handbook Part 1 , Principles and Practice of

Neutron Radiography.b) Neutron Radiography Handbook Part 3, Beam and Image Quality

Indicators for Neutron Radiography.c) Neutron Radiography Handbook Part 4, Reference Radiographs of

Defects in Nuclear Fuel.d) Neutron Radiography Handbook Part 5, List of Neutron Radiography

Facilities in the European Community.


2.2 ORDERING INFORMATIONThe following list gives the information which is recommended for inclusion in a Purchase Order for the services covered in this recommended practice.

a. Clients name and address.b. Description of the object to be radiographed.c. Objective of the neutron radiographic examination, giving qualitative and

quantitative information.d. Information on previous radiographic examinations (including X-

radiography, gamma-radiography, etc.).e. Any radiographic parameters that must be met.f. Identification requirements.g. Radiographic density requirements.h. Radiographic quality as defined by an image quality indicator,i. Requirements for the written report.


2.3 EQUIPMENT2.3.1 General2.3.1.1 Where possible a neutron radiography facility which is most suitablefor carrying out the required detection or measurement should be used. Toobtain this requirement the advantages of optimising the geometry, neutronenergy, and beam quality should be considered whenever the facility allowsthese parameters to be controlled.

2.3.1.2 The use of the track etch technique is discussed in para. 2.4.12 and all references to 'film' in the following paragraphs relate to photographic film.Information on track-etch materials is included in the Table 2.5.


2.3.2 GeometryThe geometry may be controlled by varying the size of the beam inlet-aperture, by changing the inlet-aperture to object distance or by changing theobject to film distance (see para. 2.4.7). It is recommended that theequipment should have the facility to vary the geometry.

2.3.3 Neutron Energy2.3.3.1 The control of neutron energy is a function of both the choice of:(1) neutron source and the (2) selection of a prefered energy from the available radiation energies in the

beam. (by using filter)

The first parameter is fixed by the choise of neutron source, as shown in Tables 2.1 to 2.3. The second is controlled by the use of neutron beam filters, and some of these are listed in Table 2.4 (see Part 1 for more information on filters).



D(T,n) 42He

http://www.lanl.gov/science/1663/august2011/story5full.shtml


2.3.3.2 For the neutron radiography of nuclear fuel a beam with a cadmiumratio of at least 0.1 is recommended (?) . It is also recommended that theequipment should be capable of using a cadmium filter to allow radiographywith epicadmium neutrons (energy > 0,4 eV).


2.3.4 Beam Quality2.3.4.1 The measurement of beam quality definesa) the fast/thermal neutron ratio, i.e. the cadmium ratio,b) the gamma ray contamination, i.e. n/γ ratio,c) the degree of scatter in objects with high scattering cross sections, andd) the geometric resolution.

2.3.4.2 A knowledge of these factors provide the basis for understanding ofthe variance in radiographic results and so the measurement of beam qualityby the use of the beam quality indicator (BQI?) given at para.3 is recommended.


DiscussionSubject 1: 2.3.3.2 For the neutron radiography of nuclear fuel a beam with a cadmium ratio of at least 0.1 is recommended (?) . It is also recommended that the equipment should be capable of using a cadmium filter to allow radiography with epicadmium neutrons (energy > 0,4 eV).

Subject 2: the fast/thermal neutron ratio, i.e. the cadmium ratio,

Note: Cadmium ratioThe ratio of the response of an uncovered neutron detector to that of the same detector under identical conditions when it is covered with cadmium of a specified thickness. http://encyclopedia2.thefreedictionary.com/cadmium+ratio

(uncovered/ covered, high response/low response, cadmium ratio >1?)


DiscussionSubject : the fast/thermal neutron ratio, i.e. the cadmium ratio,

Fast neutrons only: H&D Density, D2 Fast neutron & thermal neutrons: H&D Density, D1

cadmium ratio = D2/(D1-D2) ?


2.4 RADIOGRAPHIC TECHNIQUES2.4.1 General2.4.1 .1 The resolution/detection capability of a neutron radiographic

technique increases as:

a) the variation in the specimen thickness is decreased,b) the scattering cross section of the specimen to the incident radiation in the

beam is decreased,c) the difference between the attenuation coefficient of the volume to be

detected and the surrounding material in the object is increased,d) the sensitivity of the detector to the incident radiation in the beam is

increased,e) the scattering cross section of the recording material to the incident

particle or photon coming from the detector is reduced.f) the grain size of the film is decreased.

The following recommendations are intended to give the best possibility ofdetecting a discontinuity in a nuclear fuel or to measure fuel rod dimensions.


2.4.2 Set- Up, Marking and Identification2.4.2.1 The neutron beam should be aligned with the middle of the objectunder examination and normal to its surface at that point. It is essential thatany point on the object can be identified with the corresponding point on theradiograph. To achieve this an unambiguous method of marking the objectshould be used and cadmium or plastic numerals (or other suitable shapes)should be aligned with the marks on the object.

2.4.2.2 Where it is necessary to identify the edge of a specimen that is neartransparent to the incident beam, such as a thin walled zirconium fuel can, then cadmium or plastic markers should, were possible, be placed against the (curved) surface of the specimen in order to precisely locate its position.

Note: zirconium is transparent to thermal neutrons


2.4.2.3 When using overlapping radiographs the markers should be placed soas to provide evidence that full coverage has been achieved.

2.4.2.4 Each radiograph should be identified by a unique number so that there is a permanent correlation between the object and the radiograph, and where necessary a sketch should be made of the disposition of the radiographic exposures along the specimen.


2.4.3 Image Converters2.4.3.1 The material of the converter foils should be chosen to give themaximum detection/resolution efficiency. The neutron cross section of theconverter material determines its sensitivity to the incident neutrons and itshould therefore be selected to compliment the thosen neutron energy. Part 1of this Handbook gives details of some of the measurements that have beenmade on the relative speed and resolution of various image converters. Thecommonly used image converters are:

■ Indirect (transfer) technique, dysprosium (Indium, Gold?)■ Direct technique, indium (?) and gadolinium■ Track-etch technique, boron and lithium


Table 1.4 The Characteristics of Some Possible Neutron Radiography Converter Materials [Ref. 14]




Image Converters

■ Indirect (transfer) technique, dysprosium (Indium, Gold?)■ Direct technique, indium (?) and gadolinium■ Track-etch technique, boron and lithium

Remembering & pass your

exams!


2.4.3.2 Converter foils should be as thin as possible commensurate with anadequate nuclear thickness (?) (e.g. cross section times thickness) to give therequired image density on the recording film and adequate strength forhandling. They should also bee smooth, flat and free from kinks and othersurface imperfections.


2.4.4 Image Recorders2.4.4.1 As the choice of an image recorder will depend upon the need toobtain either radiographic quality or speed, it is only possible to give generalguidance as to their selection. When high quality is required a fine grain filmor track-etch material should be used, when speed is the important parameterthen fast X-radiographic type films should be used.

2.4.4.2 The image recorders given in the following table are recommended,based upon the practical experience of radiographers.



2.4.5 Cassettes2.4.5.1 The cassette should be chosen to avoid backscatter and to obtain themaximum contact between the film and the converter foil, as loss of contactgives rise to image unsharpness.

2.4.5.2 Flat, rigid cassettes of the vacuum type should be used whereverpossible, alternatively the compression type may be employed. Flexible cassettes should only be used when it is not possible to use the types recommended above.

2.4.5.3 The contact between the foil and the film should be tested periodicallyby the 'wire-mesh' method described in Appendix Β of B.S. 4304: 1968(Specification for X-Ray Film Cassettes). (further reading)


2.4.6 Masking and Backscatter Protection2.4.6.1 A significant fraction of the thermal cross section of nuclear fuels isdue to scattering and thus the masking of the region surrounding the objectby a neutron absorbing material can be helpful in reducing scattered radiation.

2.4.6.2 Similarly, the use of neutron absorbing materials covering the shieldwalls that surround the object is also recommended as this will reduce thebackscattered radiation.

2.4.6.3 Backscatter can also be minimised by confining the neutron beam tothe smallest practical field and by placing absorbing material behind therecording film.

2.4.6.4 If there is any doubt about the adequacy of the protection frombackscattered radiation then a technique employed by X-radiography may beemployed. Attach a characteristic symbol (typically a letter B) of an absorbingmaterial to the back of the cassette and take a radiograph in the normal manner. If the image of the symbol appears on the radiograph it is an indication that the protection against backscattered radiation is insufficient.(higher or lower density?)


2.4.7 Geometry2.4.7.1 The manner in which:a) the size of the collimator inlet aperture (F)b) the distance between the inlet aperture and the object, and (D)c) the distance between the object and the image converter control the

geometric unsharpness is fully described in Part 1 of this Handbook and it is sufficient to say here that dimensions (a) and (c) should be as small aspossible and distance (b) as large as possible in order to achieve the bestresolution. (t)

Ug = Ft/D


2.4.7.2 Furthermore, the reciprocal relationship between these distancesshould be noted, in that the same fractional change in both dimensions willleave the geometric unsharpness unchanged.

2.4.7.3 It must also be recognised that the effective collimator inlet aperturesize is often not the true source size due to the finite nature of the neutronsource. It is therefore recommended that the true apperture size be measured by the method of measuring the collimator ratio as described by Newacheck and Underhill [ Ref. 55].


2.4.8 Density of the Radiograph2.4.8.1 In principle the amount of information that can be recorded on aradiographic film will increase with film density, and the recovery of thisinformation will be dependant upon the ability of the viewing equipment toilluminate the image. The practical limit to this statement is a density of about4 and in special cases such densities may be used.

2.4.8.2 However for normal radiography a density between 2 and 3 isrecommended. These values are inclusive of fog and base densities of notgreater than 0,3.


2.4.9 ContrastThe contrast of the film and hence its ability to discriminate a discontinuity,depends upon the:a) variation in specimen thickness,b) neutron energy of the beam,c) quality of the beam e.g. the variation of neutron energies and the amount

of gamma rays for the direct technique,d) scattered radiation,e) type of film,f) film development andg) film densityand their relationship are described in Part 1 of this Handbook.


2.4.10 Image Quality Indicators (IQI)2.4.10.1 An image quality indicator is a device employed to provide evidenceon a radiograph that the technique that was used was satisfactory and so theuse of image quality indicators given Part 3 of this Handbook is thereforerecommended.

2.4.10.2 The acceptable sensitivity of the radiograph should be agreed between the purchaser and supplier based upon a recommended guide value of 2%.


2.4.11 Exposure Chart/Technique Log2.4.11.1 It is recommended that operators of neutron radiographic facilitiesconstruct an exposure chart/technique log for the neutron radiography ofnuclear fuel.


2.4.11.2 This should record the following:

a. diameter of beam inlet aperture,b. inlet aperture object distance (L/D ratio),c. characteristic neutron energy (Cd ratio),d. beam quality data as measured by a beam quality indicator (BQI?),e. description or sketch of the object set-up,f. material(s) of the object,g. geometry and thickness of the material(s),h. material of the converter foil,i. type of film,j. film density on the image of the quality indicator,k. identification number of radiograph,l. exposure time,m. details of any filter used,n. type of developer used,o. processing time and temperature,p. type of image quality indicator,q. sensitivity value measured by the image quality indicator.


2.4.12 Track-Etch Techniques2.4.12.1 The selection and use of track etch materials is described in Part 1 ofthis Handbook. The recommended etching conditions for Kodak CA-8015 B,CA- 8015 and CN 85 nitrocelullose film is:■ etchant, 150 g/l potasium hydroxide (KOH)■ temperature, 40°C■ time, 30 min.

2.4.1 2.2 It is recommended that, in order to achieve a strict temperaturecontrol of the bath it should be heated in a furnace and stirred before use. Long etching times should be avoided in order to avoid sediment formation in the bath due to the camfer removed from the nitrocelullose. Agitation during the etching period causes cloudiness on the nitrocelullose film and should therefore be avoided.


2.4.12.3 When track etch materials are being used then items (h) and (i) inthe list at 2.4.11.2 will be modified as follows:

h1. type of track etch converterh2. type of track etch materiali. etching time/temp.


2.4.11.2 This should record the following: (modified for track etch radiography)

a. diameter of beam inlet aperture,b. inlet aperture object distance (L/D ratio),c. characteristic neutron energy (Cd ratio),d. beam quality data as measured by a beam quality indicator (BQI?),e. description or sketch of the object set-up,f. material(s) of the object,g. geometry and thickness of the material(s),h. Type of track etch converter, type of track etch material,i. etching time, temperature,j. film density on the image of the quality indicator,k. identification number of radiograph,l. exposure time,m. details of any filter used,n. type of developer used,o. processing time and temperature,p. type of image quality indicator,q. sensitivity value measured by the image quality indicator.


2.5 MEASUREMENT2.5.1 Definition and Methods

2.5.1.1 In the context of this document measurement may be defined as thedetermination of the physical size of some feature of a fuel pin or similar object, i.e. fuel pellet diameter or length, radial gaps, cladding thickness, etc.

2.5.1.2 Measurement may be made directly from the radiograph, making dueallowance for any enlargement or reduction caused by the radiographicconditions, or by the use of a comparitor of known dimensions which alsoappears on the radiograph.

2.5.1.3 As this document is only concerned with the radiography of nuclearfuel the following discussion will be confined to the measurement of cylindrical object.


2.5.2 The Principles of Radiographic MeasurementThe principles of radiographic measurement are described in Part 1 of thisHandbook and it is sufficient to say here that the accuracy of a radiographicmeasurement technique is dependant upon the sharpness of the image andthe contrast. The following recommendations therefore aim at optimising thesharpness and the related contrast of the image and proposes variousmethods of enhancing the image and taking dimensional measurement from it.


Fuel Pins

http://jolisfukyu.tokai-sc.jaea.go.jp/fukyu/mirai-en/2009/1_2.html


Fuel Pellets

https://geoinfo.nmt.edu/resources/uranium/power.html


2.5.3 The Neutron Radiographic TechniqueAs the object of radiographic measurement of nuclear fuel is to make aquantitative evaluation of the results of irradiation then the object will beradioactive and hence a transfer technique must be used. The followingdiscussion will therefore assume the use of the transfer technique, whilstaccepting that for non-irradiated specimens it may be convenient to makesome exposures by the direct technique.


2.5.4 Making the Radiograph2.5.4.1 Every precaution should be taken to ensure a sharp image of adequate contrast, by:

a. elimination of all relative movement of the object and the image converterrecorder combination,

b. using a high geometric sharpness,c. using a high resolution image recorder,d. using a high resolution converter foil,e. optimising the neutron energy and image converter relationship,f. ensuring that the beam is well collimated,g. using a vacuum cassette,h. avoiding back scatter,i. careful preservation and handling of the image recorder and films,j. avoidance of fogging on photographic image recorders,k. careful development techniques.

2.5.4.2 When the radiograph has been produced it should be kept in aprotective envelope at all times and under storage conditions recommended by the manufacturer.


2.5.5 Making the Measurements2.5.5.1 The following sections give, where possible, data in support of theitems listed in 2.5.4.1 above. This data has been extracted from thereferences given in Part 1 of this Handbook. The following is therefore asummary of the practices used by experienced radiographers and is notnecessarily well supported by a complete theoretical understanding. It mayalso be dependant upon the characteristics of the neutron radiographyequipment in use.

2.5.5.2 In making these recommendations it is recognised that the final resultis dependant upon the combined effect of all the above variables, and so it is of little use to devote resources, say, to achiving a very high geometric resolution when the resolution of the image recorder is very poor. The problem of determining how much improvement should be made to any particular aspect of the radiographic system can only be resolved bymeasuring the transfer function of each component in the system, and as thisis difficult and costly, it is normally beyond the scope of practicingradiographers.


2.5.5.3 The data given below should therefore be used with the abovereservation in mind as it does not represent an optimum set of conditions, butonly a consensus of opinion.

2.5.5.4 Vibration can be a problem when there are machines (e.g. cranes etc.)is use in nearby buildings. This should be verified by taking both short and long exposures of the object with a camera, using a slow speed photographic film, with the camera mounted on a base that is relatively unaffected by thevibrations.

2.5.5.5 Geometry. The collimator ratio (L/D) should be 100 or higher, but it isconsidered that the advantages of increasing the ratio greater than 300 arediminishing.

2.5.5.6 Converter foils for the transfer method are limited to indiumdysprosium, and gold, all of which emit a particle of approximately 1 MeV, i.e.long range and not conducive to high resolution. However, the dysprosium foils are thinner and therefore have better resolution capability. A thickness of0,025 mm (25μm) or less is recommended.


Table 1.4 The Characteristics of Some Possible Neutron Radiography ConverterMaterials [Ref. 14]




2.5.5.7 Image recorders to be used for measurement are film or celuloseacetate. Films are discussed in para. 2.4. Celulose acetate has the higherresolution, but very low contrast. It is recommended that an increase incontrast is obtained by copying the original on to Kodalith film type 2571 bymeans of a point source, or condenser type, photographic enlarger.

2.5.5.8 Neutron energy and image converter combination. It is recommendedthat indium, and dysprosium converters are used with thermal neutrons andindium and gold converters for epithermal neutrons.

■ thermal neutrons radiography - indium, and dysprosium converters ■ epithermal neutrons radiography - indium and gold converters


2.5.5.9 Collimation is dependant upon the L/D ratio and this is discussed inpara. 2.5.5.5. It is also dependant upon the detail design of the collimator andthis is described in Part 1 of this Handbook. It is recommended that a beamquality indicator should be used to measure the characteristics of the beam and the values given in part 3 of the handbook are recommended.


2.5.5.10 Cassettes of the vacuum type are recommended.

2.5.5.1 1 Backscatter should be measured by the method given in para. 2.4.6.4.

2.5.5.1 2 Preservation and handling of the converter foils and films shouldfollow an established routine using the following recommendations:

a) store in a container that preserves the surface condition and the flatness,b) never handle the image recording surface,c) ensure that the previous image is fully decayed before re-use,d) keep the recording surfaces clean and bright,e) the recommendations of para. 2.7.3 on handling should be followed.


2.5.5.13 Fogging of photographic films may be avoided by checking that;cassettes are fully light-tight and that the recommendations of Section 2.7 arefollowed.

2.5.5.14 Development techniques given in Section 2.8 should be followed.


2.5.6 Image Enhancement2.5.6.1 Electronic MethodsSome advantages can be gained by using electronic enhancement systems to improve the contrast and resolution at the edge of a specimen or internalfeature. An iterative process is usually required. However, care must be takento ensure that the results so obtained are meaningful by making frequentreference to image quality indicators or the dimensions of reference featureswithin the radiograph.

2.5.6.2 Optical Methods Improvements can be made by magnifing the image by optical projection. A magnification of up to 10x is recommended.


2.6 SAFETY PRECAUTIONS2.6.1 Whenever a neutron radiography facility is in use it is essential thatadequate precautions are taken to protect the operator and other persons in the vicinity from uncontrolled exposure to radiation.

2.6.2 It is recommended that these precautions should adhere to the localsafety rules and that there should be a written procedure describing every type of neutron radiographic technique in use and the individual steps in eachtechnique. This procedure should include the health physics controls that shall be applied, as agreed with the local area Health Physics Officer.

2.6.3 The responsibility for following the procedure shall be clearly stated inwriting and it is recommended that the person responsible for Health PhysicsControl shall make regular audits to ensure that the procedure is being followed.


2.7 FILM HANDLING2.7.1 Storage of FilmUnexposed films should be stored in such a manner that they are protected from the effects of light, pressure, excessive heat, excessive humidity,damaging fumes or vapours, or penetrating radiation. Film manufacturesshould be consulted for detailed recommendations on film storage. Storage offilm should be on a 'first in', 'first out' basis.

2.7.2 Safelight Test Films should be handled under safelight conditions in accordance with the film manufacturer's recommendations.


2.7.3 Cleanliness and Film Handling2.7.3.1 Cleanliness is one of the most important requirements for goodradiography. Cassettes and screens must be kept clean, not only because dirtretained may cause exposure or processing artifacts in the radiographs, butbecause such dirt may also be transferred to the loading bench andsubsequently to other films or screens.

2.7.3.2 The surface of the loading bench must also be kept clean.

2.7.3.3 Films should be handled only at their edges and with dry, clean hands,since finger marks are often recorded.

2.7.3.4 Sharp bending, excessive pressure and rough handling of any kindmust be avoided.


2.8 FILM PROCESSING2.8.1 GeneralTo produce a satisfactory radiograph, the care used in making the exposure must be followed by equal care in processing. The most careful radiographictechniques can be nullified by incorrect or improper darkroom procedures.

2.8.2 Automatic Processing The essence of the automatic processing systemis control. The processor maintains the chemical solutions at the propertemperature, agitates and replenishes the solutions automatically andtransports the films mechanically at a carefully controlled speed troughout theprocessing cycle. Film characteristics must be compatible with processingconditions. It is, therefore, essential that the recommendations of the. film,processor and chemical manufacturers be followed.


2.8.3 Manual Processing2.8.3.1 This section outlines the steps for one acceptable method of manualprocessing. Modifications, provided they are shown to be adequate, may alsobe used.

2.8.3.2 PreparationNo more film should be processed than can be accomodated with a minimum separation of 12 mm. Hangers are loaded and solutions stirred before starting development.

2.8.3.3 Start of DevelopmentStart the timer and place the films into the developer tank. Separate to aminimum distance of 12 mm and agitate in two directions for about 15 s.


2.8.3.4 Development Normal development is 5 to 8 min at 20°C. Longer development time generally yields faster film speed and slightly more contrast. The manufacturer's recommendations should be followed in choosing adevelopment time. When the temperature is higher or lower, developmenttime must be changed. Again, consult manufacturer-recommendeddevelopment time versus temperature charts. Other recommendations of themanufacturer to be followed are replenishment rates, renewal of solutions andother specific instructions.

Note:■ Normal development is 5 to 8 min at 20°C.■ Longer development time generally yields faster film speed and slightly

more contrast.


2.8.3.5 Agitation Shake the film horizontally and vertically, ideally for a few seconds each minute during development. This will help film develop evenly.

2.8.3.6 Stop Bath or Rinse After development is complete, the activity of developer remaining in the emulsion should be neutralised by an acid stop bath or, if this is -not possible, by rinsing with vigorous agitation in clear water. Follow the film manufacturer's recommendation of stop bath composition (or length of alternative rinse), time immersed and life of bath.

2.8.3.7 Fixing The films must not touch one another in the fixer. Agitate the hangers vertically for about 10 s and again at the end of the first minute, to ensure uniform and rapid fixation. Keep them in the fixer until fixation is complete (that is, at least twice the clearing time), but not more than 15 min in relatively fresh fixer. Frequent agitation will shorten the time of fixation.


2.8.3.8 Fixer Neutralising (?)The use of a hypo eliminator or fixer neutraliser between fixation and washing may be advantageous. These materials permit a reduction of both time and amount of water necessary for adequate washing. The recommentations of the manufacturers as to preparation, use and useful life of the baths should be observed rigorously.

2.8.3.9 WashingThe washing efficiency is a function of wash water, its temperature and flowand the film being washed. Generally washing is very slow below 1 6°C.When washing at temperatures above 30°C, care should be excercised not to leave films in the water too long. The films should be washed in batcheswithout contamination from new film brought over from the fixer. If pressed forcapacity, as more films are put in the wash, partially washed film should bemoved in the direction of the inlet.

2.8.3.10 The cascade method of washing uses less water and gives betterwashing for the same length of time. Divide the wash tank into two sections(maybe two tanks). Put the films from the fixer in the outlet section to the inletsection. This completes the wash in the fresh water.


2.8.3.11 For specific washing recommendations, consult the film manufacturer.

2.8.3.12 Wetting Agent Dip the film for approximately 30 s in a wetting agent. This makes water drain evenly off film which facilitates quick, even drying.

2.8.3.13 Fixer Concentrations (residual on dry film)If the fixing chemicals are not removed adequately from the film they will in time cause staining or fading of the developed image. Permissible residual fixer concentrations depend upon whether the films are to be kept for commercial purposes (3 to 10 years) or must be of archival quality. Archival quality processing is desirable for all radiographs whenever average relative humidity and temperature are likely to be excessive, as is the case in tropical and subtropical climates. The method of determining residual fixer concentrations may be ascertained by reference to ANSI PH4.8., PH1.28, PH4.32 and PH1.41.


2.8.3.14 Drying Drying is a function of:

1. film (base and emulsion);2. processing (hardness of emulsion after washing, use of setting agent);

And3. drying air (temperature, humidity, flow).

Manual drying can vary from still air drying at ambient temperature to as high as 60° C with air circulated by a fan. Film manufacturers should again be contacted for recommended drying conditions. Take precaution to tighten film on hangers so that it cannot touch in the dryer. Too hot drying temperature at low humidity can result in uneven drying and should be avoided.


2.8.3.15 It is desirable to monitor the activity of the radiographic developingsolution. This can be done by periodic development of film strips exposed under carefully controlled conditions, to a graded series of radiation intensities or time, or by using a commercially available strip carefully controlled for film speed and latent image fading.


Manual Processing

https://www.youtube.com/watch?v=jIQuN7ZVB48

■ https://www.youtube.com/embed/jIQuN7ZVB48


2.9 VIEWING RADIOGRAPHS2.9.1 The illuminator must provide light of an intensity that will illuminate theaverage density areas of the radiographs without glare and it must diffuse thelight evenly over the viewing area. Commercial fluorescent illuminators aresatisfactory for radiographs of moderate density; however, high intensityilluminators are available for densities up to 3,5 or 4,0. Masks should beavailable to exclude any extraneous light from the eyes of the viewer whenviewing radiographs smaller than the viewing port or to cover low-densityareas. Viewing radiographs requires considerable handling; therefore, it isrecommended that films be handled with extreme caution.

2.9.2 Subdued lighting, rather than total darkness, is preferable in the viewing room. The brightness of the surroundings should be about the same as the area of interest in the radiograph. Room illumination must be so arranged that there are no reflections from the surfaces of the film under examination.


2.10 REFERENCE RADIOGRAPHSPart 4 of this Handbook consists of a collection of reference radiographs which show defects in nuclear fuel. It is recommended that these radiographsbe used when making interpretations and that whenever possible theapplicable reference radiograph number should be quoted in the report on theinterpretation.


2.11 STORAGE OF RADIOGRAPHSRadiographs should be stored using the same care as for any other valuablerecord. Envelopes having an edge seam, rather than a centre seam and joined with a nonhygroscopic adhesive, are preferred, since occasionalstaining and fading of the image is caused by certain adhesives used in themanufacture of envelopes (see ANSI PH4.20).


2.12 RECORDS AND REPORTS2.12.1 RecordsIt is recommended that a work log (a log may consist of a card file, punchedcard system, a book, or other record) constituting a record of each jobperformed, be maintained. This record should comprise, initially, a jobnumber (which should appear also on the films), the identification of the parts,material or area radiographed, the data the films are exposed and a completerecord of the radiographic procedure, in sufficient detail so that anyradiographic techniques may be duplicated readily. If calibration data, or otherrecords such as card files or procedures, are used to determine theprocedure, the log need refer only to the appropriate data or other record.Subsequently, the interpreter's findings and disposition (acceptance orrejection), if any, and his intials, should also be entered for each job.


2.12.2 ReportsWhen written reports or radiographic examinations are required they shouldinclude the following, plus such other items as may be agreed upon:

a) Identification of parts, material or area.b) The radiographic job number.c) The findings and disposition, if any.

This information can be obtained directly from the log.


3. NRWG INDICATORS FOR TESTING OF BEAMPURITY, SENSITIVITY, AND ACCURACY OFDIMENSIONS OF NEUTRON RADIOGRAPHS

a. Beam purityb. Sensitivityc. Accuracy of dimension


For the sake of testing the radiographic image quality and accuracy of dimension measurements from neutron radiographs of reactor fuel, the NRWG (Nuclear Regulator Working Group) has decided to produce and test special indicators developed for that purpose. In the preliminary investigation it was determined that there are no suitable indicators prescribed in the existing standards on neutron radiography.

The only published standard in that field [ Ref. 1 ], the ASTM E 545-75, was prepared for general neutron radiography and is now under revision. Taking into account the work done on this revision (as e.g. Described in [Ref. 2]) as well as different proposals made -by the NRWG members [ Refs. 3, 4, 5 ], it was decided to produce the following indicators for neutron radiography of nuclear fuel :

- Beam Purity Indicator (BPI)- Beam Purity Indicator- Fuel (BPI-F)- Sensitivity Indicator (SI)- Calibration Fuel Pin (CFP-E1)


Those indicators, fabricated at Rise National Laboratory *, were distributed among all NRWG participants and will be tested under a special NRWG TestProgram [Ref. 6]. The design of the above-mentioned indicators is describedbelow. It is worth noting that some work is going on in the NRWG on thedevelopment of a common Sensitivity and Measurement Indicator- Fuel (SMI-) and a Combined Quality Indicator (QIF), as described in [ Ref. 4]. Thoseindicators are not yet included within the present Test Program [ Ref. 6].

* on behalf of the Petten Establishment of the Joint Research Centre of the Commission of theEuropean Communities.


3.1 THE VARIOUS INDICATORS3.1.1 Beam Purity Indicator (BPI)The neutron beam and image system parameters that contribute to film exposure and thereby affect overall image quality can be assessed by the useof Beam Purity Indicators. Following the experience gained during the use ofthe BPI prescribed by the first ASTM standard on neutron radiography [ Ref. 1]a new BPI design was developed, which will be recommended by the revisedASTM standard. This design , shown on Fig. 3.1, was adopted by the NRWG,and will be tested under its Test Program [ Ref. 6].


Fig. 3.1 The ASTM Beam Purity Indicator.



Picture and drawing of Beam Purity Indicator


ASTM Designation: E 545-99Standard Test Method forDetermining Image Quality in Direct Thermal NeutronRadiographic Examination

ASTM Designation: E 2003-98 Standard Practice forFabrication of the Neutron Radiographic Beam PurityIndicators


Standard Test Method forDetermining Image Quality in Direct Thermal NeutronRadiographic ExaminationDesignation: ASTM E 545 – 99


TABLE 1 Definitions of D ParametersDB Film densities measured through the images of the boron nitride disks.DL Film densities measured through the images of the lead disks.DH Film density measured at the center of the hole in the BPI.DT Film density measured through the image of the polytetrafluoroethylene.DDL Difference between the DL values.DDB Difference between the two DB values.


BPI RadiographDB Film densities measured through the images of the boron nitride disks.

DL Film densities measured through the images of the lead disks.

DT Film density measured through the image of the polytetrafluoroethylene.

Cd wire

Void


BPI RadiographDDB Difference between the DL values

DDL Difference between the DL values.

DH Film density measured at the center of the hole in the BPI.

Cd wire

Void


BPI Radiograph


BPI Radiograph

DL1

DL2


The body of the BPI is made of a 8 mm thick teflon (26 mm x 26 mm) plate. It has a central hole of 16 mm in diameter. In the teflon plate two grooves toaccommodate 0,64 mm cadmium wires are made, separated by 10 mm fromeach other. At the top and bottom of the teflon plate two holes, 4 mm indiameter and 2 mm deep, are machined. At each side of the BPI a boronnitride BN and a lead disc Pb (2 mm thick) are inserted into the circular holes.

Key feature of the device is the ability to make a visual analysis of its image for subjective quality information. Densitometrie measurements of the image of the device permit quantitative determination of:■ radiographic contrast, ■ low energy gamma contribution,■ pair production contribution, ■ image unsharpness, and ■ information regarding film and processing quality.

To be able to identify the orientation of the BPI on neutron radiographs, one corner of the indicator was cut off (not shown on Fig. 3.1).


3.1.2 Beam Purity Indicator- Fuel (BPI-F)For controlling the neutron beam components in nuclear fuel radiography the NRWG has developed a special Beam purity Indicator -.Fuel, which ¡s amodification of the ASTM BPI (See. Fig. 3.2).


The body of the BPI-F consists of a 6 mm thick aluminium plate (Not Teflon)(26 mm x 26 mm), in which a 16 mm round central hole is machined. At the top and bottom of the Al plate two pairs of round holes (4 mm in diameter and 2 mm deep) are made to accommodate 2 mm thick boron nitride and cadmium discs (not Lead discs). (the disc combination is BN/Cd not BN/Pb in BPI)

Through those holes square grooves (2x2 mm2) are machined toaccommodate 12 mm long square (2x2 mm2) cadmium bars.

The reasons behind the modification of the ASTM BPI are explained in [Ref. 3] as follows : “The materials of the ASTM BPI were principally chosen to be suitable for the detection of gamma rays and as it is assumed that when the BPI-F is in use, a transfer or track etch technique will be used, clearly a sensitivity to gammas is not needed. It is therefore considered that the base material should be aluminium and that the filter-discs should be boron nitride and cadmium (the ASTM design has boron nitride and lead discs)".


Fig. 3.2 Beam Purity Indicator-Fuel (BPI-F).



To be able to identify the orientation of the BPI-F on neutron radiographs one corner of the indicator was cut off (not shown on Fig. 3.2).

From measurements of film densities under different parts of the BPI-F, andbackground density, different neutron beam components can be calculated.

The cadmium wires or rods included in each beam purity indicator are used toprovide an indication of inherent beam resolution or sharpness.


3.1.3 Sensitivity Indicator (SI)Instead of the former four types of ASTM Sensitivity Indicators [Ref. 1] one new type of SI was developed (Fig. 3.3). This sensitivity indicator basicallycombines a hole gauge and gap gauge into a small single device. The holesare sized to be smaller than can be seen by conventional neutronradiography, and they progress up in size. Similarly, the gaps formed by aluminium shims between sheets of acrylic resin cover a range that is useful for all facilities. The NRWG has considered a special design of a sensitivity indicator, including steps and shims of UO2, which could be useful in evaluating the image quality of neutron radiographs of nuclear fuel. Unfortunately, it is technically not feasible to construct such an indicator and therefore the ASTM SI was adopted by the NRWG for its Test Program.


3.1.4 Calibration Fuel Pin (CFP-E1)As mentioned in [Ref. 2] ; "The design goal for the ASTM sensitivity indicator is to provide the maximum sensitivity information in an easy to manufactureand easy to interpret configuration.

It is recognized that the only true valid sensitivity indicator is material or component, equivalent to the part being neutron radiographed, with a knownstandard discontinuity (reference standard comparison part)". Such a "reference standard comparison part" for nuclear fuel pins is the calibration fuel pin CFP-E1 (Fig. 3.4). It is described in [Ref. 7]. According to the specifications given in [ Ref. 7] ten calibration fuel pins were produced at Riso and distributed among the NRWG members to be tested under the Test Program [ Ref. 6].


The calibration fuel pin CFP-E1 (Fig. 3.4) incorporates the following features:

From the nine UO2 pellets two are made of natural, and seven of enriched uranium.

All the pellets have a different length. The two pellets made of natural uranium and one pellet of enriched

uranium have a constant diameter on all their lengths, to fit closely into the zircaloy cladding tube (practically no fuel-to-cladding gaps).

The remaining six UO2 pellets of enriched uranium have a reduced diameter on half of their lengths so as to form a calibrated fuel-to-cladding gap. These radial gaps are 50, 100, 150, 200, 250 and 300 μm wide.

The first UO2 pellet from natural uranium and the first pellet of enriched uranium have a dishing 0.3 mm deep on the surfaces facing each other.


There are aluminium spacers between all UO2 pellets from enriched uranium. They are simulating the pellet-to-pellet gaps. The thicknesses of those spacers are the same as the fuel-to-clad gaps, i.e. 50, 100, 150, 200, 250 and 300 μm respectively.

All UO2 pellets made of enriched uranium have a calibrated central void. The diameter of this void is 4000 μm increasing by an increment of 100 μm throughout the consecutive pellets to a diameter of 4 600 μm, respectively.


Fig. 3.3 ASTM sensitivity Indicator


Fig. 3.4 ASTM sensitivity Indicator


BPI & ASTM sensitivity Indicator


BPI Radiograph


Correct placement of Indicators in part holder


Fig. 3.4 Calibration Fuel Pin (CFP-E1)


3.2 ASSESSMENT OF TEST RESULTS FOR THE INDICATORS

3.2.1 Assessment for the Beam Purity Indicator (BPI) From the neutronradiographs of the BPI, the following film densities are to be measured:

D1 - density under the lower boron nitride discD2 - density under the upper boron nitride discD3 - density under the lower lead discD4 - density under the upper lead disc

D5 - background film density in the center of the holeD6 - film density through the teflon body.


TABLE 1 Definitions of D ParametersDB Film densities measured through the images of the boron nitride disks.DL Film densities measured through the images of the lead disks.DH Film density measured at the center of the hole in the BPI.DT Film density measured through the image of the polytetrafluoroethylene.DDL Difference between the DL values.DDB Difference between the two DB values.


From those values the neutron exposure contributions can be calculated as follows :



D5D2 D1

BN

BN



D5D4 D3

Pb

Pb

D6




BPI Radiograph


The film density shall be measured using a diffuse transmission densitometer. The densitometer shall be accurate to ± 0.04 and repeatable to ± 0.02 density units. Besides the above-mentioned density measurements and calculations from the radiograph of the BPI one shall further visually compare the images of the cadmium rods in the beam purity indicator. An obvious difference in image sharpness indicates an L/D ratio which is probably too low for general inspection. Detailed analysis of the rod images is possible using a scanning microdensitometer.


Pair Production


Pair Production


Pair Production

http://pages.uoregon.edu/jimbrau/astr123/Notes/Chapter27.html


3.2.2 Assessment for the Beam Purity Indicator- Fuel (BPI-F)From the neutron radiographs of the BPI-F, the following film densities are to be measured :DD - density under the lower boron nitride discDB - background film density in the center of the holeDC - density under the upper boron nitride discDE - density under the upper cadmium discDF - density under the lower cadmium disc.


From those values, exposure contributors can be calculated as follows :

Besides the above mentioned density measurements and calculations from the radiographs of the BPI-F, inherent and total unsharpness can be determined.


3.2.3 Assessment for the Sensitivity Indicator (SI)The purpose of the sensitivity indicator is to determine the sensitivity of details visible on the neutron radiograph by evaluating the neutron radiographicimage of the SI. Besides one shall visually inspect the image of the lead stepsin the sensitivity indicator. If the 0,25 mm holes are not visible, the exposurecontribution from gamma radiation is very high and further analysis should bemade. The lead steps are shown on Fig. 3.3; under the steps a 0,25 mm thickacrylic shim D is located with four 0,25 mm holes. When examining theneutron radiographs of the SI, one shall visually inspect the image of the castacrylic resin steps and note all the holes visible to the observer (consecutiveholes marked as H). Then one shall take as the value of Η reported thelargest consecutive value of Η that is visible in the image. The cast acrylicresin steps, shown on the left side of the SI (see Fig. 3.3) are separated byaluminium spacers with thickness (gap size) marked as G. During the visual examination of the neutron radiograph of the SI one shall report theG value. The value of G reported is the smallest gap which can be seen at all absorber thicknesses.


3.2.4 Assessment for the Calibration Fuel Pin (CFP- E1)From the neutron radiographs of the CFP-E1 the following dimensions ought to bedetermined (see Fig. 3.4) :


Axial dimensions (read along the longitudinal axis of the pin)• Total fuel stack length (from the beginning of pellet N-j to the end of pellet

N2).• Length of all pellets separately.• Length of the central void.• Dishing between pellets N1 and E0.• Pellet-to-pellet gaps.


Radial dimensions• Pellet diameters of nonstepped pellets (measured in the middle of the

pellets N1, E0 and N2).• Pellet diameters of stepped pellets (measured in the middle of the

nonstepped and in the middle of the stepped half of each pellet).• Pellet-to-pellet gaps (both gaps at each pellet).• Cladding tube wall thickness (measured at the same radius as the

diameter and gap measurements).• Central void diameter (measured in the middle of the void length).


All the above-mentioned measurements shall be performed using those measuring instruments (e.g. scanning microdensitometer, projectionmicroscope) available at the various centers. As described above, fromneutron radiographs of the CFP- both axial as well as radial dimensions canbe read. The results of those measurements shall be compared with the truedimensions as given in the CFP- E1 certificate.


4. ATLAS (COMPACT VERSION) OF DEFECTSREVEALED BY NEUTRON RADIOGRAPHY IN LIGHT WATER REACTOR FUEL


4.1 INTRODUCTIONThe assessment of neutron radiographs of nuclear fuel pins can be done much easier, faster and simpler if reference can be made to typical defects,which can be revealed by neutron radiography. In the fields of industrial 7-adiography such collections of reference radiographs, showing typical defectsin welding, or casting have been compiled and published some time ago.Since the early 1970's neutron radiography is routinely used for the qualityand performance control of nuclear fuel. During the assessment of neutronradiographs, some typical defects of the fuel were found and it was felt that aclassification of such defects would help to speed up the assessmentprocedure. Therefore, in the frame of the programme of the NeutronRadiography Working Group, an atlas of reference neutron radiographs hasbeen compiled [Ref. 1], which was printed as a working document on behalfof JRC Petten in June 1979.


It contains a collection of typical defects revealed by neutron radiography in light water reactor fuel, which are reproduced on X- ay film (original size) and as enlargements (2x) on photographic paper. A revised version of the atlas, which is supplemented with further examples of typical defects is under preparation and will be edited by the Neutron Radiography Working Group. It was not possible to reproduce in the handbook all the neutron radiographs contained in the atlas. Therefore a selection was made of those enlargements which illustrate the most characteristic defects occurring in light water reactor fuel.


4.2 RELEVANT NOTES4.2.1 Fuel PinsFor the purpose of the present collection of neutron radiographs a typical example of a nuclear fuel pin , used in light water reactors, was chosen. Fig.4.1 shows all the components of such a fuel pin where defects, detectable byneutron radiography, can occur.


Those components are marked with capital letters as follows:- Nuclear fuel : "A"- Fuel Cladding : "B"- Plenum : "C"- End plugs: "D"- Instrumentation : "E".

Cha

rlie

Cho

ng/ F

ion

Zhan

g

Fig. 4.1 Components of a typical nuclear fuel pin.

Cha

rlie

Cho

ng/ F

ion

Zhan

g

Fig. 4.1 Components of a typical nuclear fuel pin.


4.2.2 DefectIn the present collection of neutron radiographs the term "defect" is used for designation of a neutron radiographic finding, showing a different appearanceof a particular part of the fuel, different from that, which will be shown on aneutron radiograph of that part as fabricated. The term "defect" is thereforeused in a rather general and neutral significance. A "defect" in the sense ofthis Handbook does not necessarily disqualify a fuel pin for further normaloperation.


4.2.3 Defect LocationOn Fig. 4.2 the fuel pin components shown on Fig. 4.1 are subdivided into elements where defects may occur (listed in the vertical column at the l eftand marked with small letters).


Fig. 4.2 Fuel pin components and defects occuring in them.


4.2.4 Defect Nature and OriginDefects which may occur in different elements of the fuel pins can be of different nature and origin. They are listed at the top of Fig. 4.2 (columns 1 to21 ) .

4.2.5 Defect Occurrence On Fig. 4.2 the sign "●" signifies, that in that location a particular defect can occur and that this defect is illustrated in the present collection. There are, however, more defects which can most likely occur in nuclear fuel and can be detected by neutron radiography, but which are not found among the radiographs of the Atlas. They are marked "o" on Fig. 4.2.


4.2.6 Defect IntensityDefects in nuclear fuel can occur with different intensity (e.g. cracks in fuel pellets can be miniscule, slightly visible, or so big as to break the wholepellet). Therefore it was felt that one shall also classify the intensity of thedefects. For that purpose an arbitrary three grade scale was adopted: 1 - meaning small, 2 - medium and 3 - high intensity defect.

This intensity classification is used routinely for the assessment of defectsrevealed by neutron radiography.

4.2.7 Dimensions It is also possible to measure dimensions from neutron radiographs. Therefore the last three columns (22 to 24) at the top of Fig. 4.2 list those dimensions.


4.2.8 Measuring of DimensionsBesides the defects, dimensions of various elements of the fuel pins can be determined from neutron radiographs. Those instances are marked "x" on Fig.4.2 and those which are routinely measured during the assessment ofneutron radiographs are marked with “◙”


4.3 THE COLLECTION OF THE ATLAS4.3.1 Contents of the Collection in Ref 1.The collection of the Atlas contains neutron radiographs of defects marked with "o" on Fig. 4.2 (see also chapter 4.2.5).

The original neutron radiographs were taken at the DR1 RISØ reactor (2 kW) on double coated Agfa Gevaert Structurix D4 X-ray film. A transfer technique was used with a 0.1 mm dysprosium foil. Exposure time was about 30 min. to a 1.6 x 106 n.cm2s-1 neutron beam (10 x 10 cm2).

The L/D ratio in the vertical direction of the neutron beam (perpendicular to the fuel pin axis) was 110 and in the horizontal direction (coinciding with the pin axis) was 27,5.

The radiographs in the Atlas are reproductions of the original neutron radiographs copied on Kodak X-Omat Duplicating Film. The original neutron radiographs were also photographed on a 35 mm Agfapan 100 film and thereafter enlarged (2x) on photographic paper. A selection of these enlargements is also included in the present publication.


4.3.2 The Use of the Collection in Ref. 1The copies of the neutron radiographs on film can be viewed without removing them from the Atlas, because there is a blank page following eachcopy. This blank page can be illuminated by a shaded desk lamp. Ifnecessary the reference radiograph may be removed from the collection to beviewed on an illuminator together with the radiograph under assessment forcomparison.


4.3.3 The Selection of Characteristic DefectsA selection of defects revealed by neutron radiography in light water reactor fuel is given below. Enlargements (magn. 2x) of neutron radiographs onphotographic paper are reproduced. The defects' location and their natureand origin are marked according to the classification adopted on Fig. 4.2.


Insert Page 137~149

A. Defects in fuel

A.a Defects in pellets

123

Cracks in pellets are i l lustrated in Fig. 4.3, whereas Fig. 4.4 shows chips of pellets. On Fig. 4.5 enlarged and broken pellets are shown.

A.a.2 Longitudinal cracks

Fig. 4.3 Cracks in pel lets.

A.a.3 Transverse cracks

A.a.5 Corner chips

124

A.a.6 Other chips

Fig. 4.4 Chips of pellets

A.a.7 Chips i n

pellet-to-pel let gap

A.a . 1 0 Pel let enlarged

125

A.a.1 9 Broken pellet

Fig. 4.5 Enlarged and broken pellets

A.b Defects in pellet-to-pellet gap

126

On Fig. 4.6 both an enlarged as well as a contracted pellet-to-pellet gap can be seen.

A.b.10 Pellet-to· pellet gap enlarged

A.b. 1 1 Pellet-to-pellet gap contracted

Fig. 4.6 Pellet-to-pellet gap enlarged and contracted

A.c Defects in dishing

127

A filled up and deformed dishing can be seen on Fig. 4.7.

A.c.1 2 A.c. 1 3 Dishing filled-up Dishing deformed

Fig. 4.7 Fil led -up and deformed dishing.

A.d Central void

128

Central void can be detected in one pellet or going through several pellets (as shown on Fig. 4.8) or can even go through the whole fuel column.

A.d.14 Central void in one pellet

A.d.1 5 Central void

through several pel lets

Fig. 4.8 Central void in one and in several pel lets

A.e Defects of fuel-to-clad gap

Defects of fuel-to-clad gap are hard to detect and even harder to reproduce in print. Therefore no such example is given here.

B. Defects in cladding

B.a Deformed and broken cladding

129

A deformed arid broken cladding can be seen on Fig. 4.9.

B .a.1 3 Cladding deformed

B.a. 1 9 Cladding broken

f:ig. 4.9 Deformed and broken cladding

B.a Hydrides in cladding

130

Hydrides in cladding, although relatively easi ly detected on neutron radiographs, can hardly be seen when reproduced in print. Fig. 4.1 0 shows some hydrides revealed in the cladding.

+

B.a.1 8 Hydrides in cladding

B.a. 1 8 Hydrides i n cladding

Fig. 4.1 0 Hydrides in cladding.

C. Defects in plenum

C.a Defects of spring

131

Different defects of the spring in plenum are i l lustrated on Fig. 4.1 1 .

C.a. 1 1 Spring contracted

C.a.1 3 Spring deformed

Fig. 4. 1 1 Defects of the spring in plenum

C.a.20 Spring dislocated

C.b Defects of spring sleeve

132

Fig. 4.1 2 il lustrates a broken spring sleeve.

C.a. 1 9 Spring sleeve broken

Fig. 4.12 Broken spring sleeve

C.c Disc

133

The disc separating the spring of the plenum from the last (or first) pellet can be dislocated, as shown on Fig. 4.13.

C.c.20 Disc dislocated

Fig. 4.1 3 Dislocated disc

D. Defects in end plugs

134

Fig. 4. 14 il lustrates hydrides detected in the bottom plug. Other defects can be detected by neutron radiography as well.

D.a. 1 8 Hydrides in plug

Fig. 4.14 Hydrides in the bottom plug

E. Instrumentation

135

Defects in various instruments (e.g. thermocouples, pressure transducers) located in fuel pins can be revealed. by neutron radiography. Fig. 4.1 5 gives an example of a dislocated thermocouple.

E.a.20 Thermocouple dislocated

Fig. 4. 1 5 Dislocated thermocouple


Defects not shown in the present CollectionIn the Atlas only those defects in nuclear fuel are shown which could be chosen from the available neutron radiographs. There are, however, moredefects which can most likely occur in nuclear fuel and can be detected byneutron radiography. Those defects were marked "o" on Fig. 4.2. It is alsopossible to find some other typical defects in nuclear fuel worth including inthis collection. Therefore all persons in possession of such neutronradiographs, missing in this collection, are kindly asked to supply them to : JRC Petten Secretary of the NRWG HFR Division P.O. Box 2 1755 ZG Petten,The Netherlands They will be included in the next edition of the Atlas.


Insert Page 151~184

Table 5.1 Neutron Radiography Installations in the European Community - Technical Data and Main Uti lization .

S1te Facil ity Camera type

I Cadarache LDAC dry

Casaccia 1 ) TR IGA· dry RC l

Fontenav· TR ITON dry aux-Roses

Geest- FRG 1 dry hacht

FRG 2 pool

1 kCi dry Sb-Be neutron source

Grenoble MELU· dry S INE

SI LOE pool

11 not operational at present

Coll imation Inlet Ratio IL/D) Diaphr.

Dimensions (mm)

13,5 70 X 30

50 (/) = 48

180 canal axial 1 1 0 to 760 canal later. 1 375 20

1 00 (/) = 20 (other possible)

1 0 . 20 20

1 25 and (2) = 50 390 and 16,2

1 380 (/) = 6

Collimator Beam Thermal Max. Obj. Lining Dimensions Neutron Dimensions

lmm), at Flue nee lmm) obj. plane rate, at

obj. plane (m·2 s·l )

Cd 500 X 1 00 ca. 1 09 500 X 100 X 60

borated (2) = 1 20 5 . 1 Q1 1 520 X 27 (/) paraffine

L = 2200mm I 0 min = 48 mm (conical tube)

7 . 1o1 o 180 x 2402)

4 . 1 01 0 300x4002)

B4C (/) = 1 80 5 . 1 010 3, 3QQ X 300

Sartdwich: 1 00 X 400 1 01 1 100 X 100 boral, length iridium, 1 700 Cd

no 200x400 1 . 5 . 1 08 3000x 1000 coll imator I B4C + In (2) = 400 2 . 1o1 1 normal

and length 2 . 1 o1 0 < 2000

(possible

I modificat. 1 for bigger objects)

first 400 X 1 32 8,5 . 1 01 1 140 X 140 '"' mm; J <••<<oo( Cd,ln,Dy, Au,Gd general l i n ing: 1 B4C, In

----'-" ��

Min. D istance Object/ Image Plan lmm)

ca. 1

8

2

2

1 0

1

2

6

2) max. dimensions of usable film 3) 0f = 101 1 m·2s ·l

Geometr. Cd·Ratio Other Unsharp· Spectrum ness Inform. m " u " "

.:: 0 "

.. ca. 9

0, 1 5 1 ,65 .. mm (measured

with Au)

below X visual percept. X faculty

26 . 50 100 X Jlm lOy O,l mm)

0,1 ·0,5 5 .. mm (Au 25pm)

90 (Dy0,1 mm)

.. 2 I .. 1Au 25pm)

ca. film 7,4 · Collimator X grain un- nose in sharp- D20 tank ness · Cold neutr.

beam faci· lity with Be-filter

.. 2.4 "'esi .. 1> .52eV) 7,9 . 10 10 m·2s · l

--

Uti I ization Approx. nuclear Number of

Exposures " per year

a: � 0 g " :; ; c:·a. � ·a. iii � -� lll s: o; :;: o; ...J .;:! ...J .;:! � ., ::.i

X 1 200 (since Aug. 1970)

X X .. ..

X X X .. 2500

X X X -..

.. .. .. X 50 to 100 � X - X .. 50

.. .. .. X 20 to 50

.. .. .. X 100 to 200

X X I X .. 100 to 1 50

Table 5.1 Contd.

S1 te Fac1hty Camera Collimation Inlet type Ratio ( L/Dl D1aphr.

Dimensions (mm)

Harwell DIDO I dly 50 I 121 = 1 50 (Beam 15m 6HI stat• on)

300 ()) = 1 50 125m station)

(Beam dry 50 ()) = 19 6HGR9)

Karlsruhe FR 2 dry 46 to 185 81 cm2 to 5,07cm2

Mol BR 1 dry 75 ()) = 30

B R 2 pool 240 0 = 1 1 I typical

I Petten H F R pool 237 8 JRC (PSFI

(HB8) dry 500 ()) = 8

Pet ten LFR dry 1 27 0 = 1 5 ECN (other

possible)

4) only for demonstration

Collimator Beam Lining Dimensions

(mm), at obj. plane

Bora! ()) = 1 50

Boral ()) = 500

Cd ·()) = 180

1 mm Cd 250 X 170

Pb ; Boral 300 X 300

Boral 1 00 X 600 IB4c)

1!4 ..

B4C 600 X 80

B4c 1 60 X 1 00

.. ()) = 250

'

Thermal Neutron Fluence rate, at obj. plane (m·2s· l )

1 01 1

3 X 109

8 X 1Ql l

0,5 to 4,5 x 1 01 0

1 .1 . 1o1o

3 . 1 Q l l

2.3 . 1o1 1

1 01 1

3 . 1 09

Max. Obi. Dimensions (mm)

500 X 500 X 500

h . 1 600 I . 1 700 w. 3400

diam. 260 I. 1730

diam. 135 I. 6000

3000 x 200 X 40

w. 1 00 I. 3000

1 50 X 200 J( 1 560

1\1. 1 00 I. 4500

7500 x5000

Min. Geometr. Cd- Ratio Other Distance Unsharp· Spectrum Object/ ness Inform. "' Image

� u

Plan ::> c: (mm) C: 0 c:

0 � 0 beryll ium X fi ltered beam

0 � 0 .. X

0 to 1 50 0 X

d irect neutrons 4) contact from therm.

column

1 1 5 1-!m > 50 (min.) (for Au)

0 (min.) 1 00 1-!m 40 spectrum .. 28 (typ.) (typical) varies with

reactor load ing

0,5 2 1-!m 10,2 .. (without object)

2 4 1-!m not yet -· measured

in 8 /lm 40,4 n/'y = X contact (without (with 1 ,6 . 1 06

object) manganese --- foils)

Util ization

nuclear c: 0 � c: o:: :e :; � cc ·a. � ·c. Til ·!: o;

;;:: o; ::;; <; &l ...J .2 ...J .2 t: � �

·- .. .. ..

.. .. .. ..

X X X X

.. .. X ·-

non destructive qual ity control of plutonium for LWR and fast reactors

X .. X ..

X X X X

X X X ..

-- .. X X

I Approx. Number of Exposures per year

mainly dynamic imaging and record ing

..

500 excl. routine radiographs of turbine blades

190 in 1978

250

1 50

300

new installation

1 00

..... w 00

Table 5.1 Contd.

Site Facility Camera Coll imation I nlet Coll imator type Ratio ( LID) Diaphr. Lining

Dimensions (mm)

I I graphite Ros� DR 1 dry 1 1 0 In 20 verti· vertical, callv, 27,5 in 80 hori-hori· zontally zontal di rection

Saclay OSI R IS pool 148 16 X 1 6 Boral S mm

IS IS pool 137 16 X 16 Boral thick-ness

S mm + ( l n ,Cd on 200 mm)

dry 94 (/) = 40 boron powder 1 0 to 12 mm

ORPHEE dry divergent: neutron 1 5' guide

Valduc M IRENE dry 100 20 X 30 1 934 tangent mm beam

30 X 30 1722 axial mm beam

.......... �-

5) d = obJeCt th1ckness in mm 7) film dimensions 6) expected 8) before irradiation

Beam Dimensions (mm), at obj. plane

twice 1 00 X 100

1 50 X 600

1 50 X 600

1 00 x 1 50

1 50 X 25

180 X 240

300 X 300

Thermal Neutron Fluence rate, at obj. plane (m·2s·1 )

1 ,8 . 1 01 0 (left part) 1 ,4 . 1 010 (right)

6,5 . 1 01 1

0,3 to 1 ,3

X 101 1

8,4 . 1 010

5 . 1 01 26)

2,6 X 101 2 10)

8,9 X 1012 10)

Max. Obi. Dimensions (mm)

twice 100 X 1 00 to be radio-graphed, otherwise no dimens. l imits

I . < 2500

1 . < 1800

I . < 4000 two tubes (/) = 20, : or one tube (/) = 43

300x40071

150x1 010

large dim ens. > 2m

..

=--= �

Min. Distance Object/ Image Plan (mm)

in contact

> 12

> 18

1 to 7

1

3500

..

�-

9) The installation at ORPHEE will replace the TR ITON installation.

Geometr. Cd· Ratio Other Unsharp· Spectrum ness Inform. � "

u :J " C: 0 "

20d 41 4,2 25 R/h X 2200·d (left port) gamma at (vertic.) 3,8 object

SOd ( right) for open

220Q:d Au beam port

3,83 ..

5,64 to 2,54

2.44 ..

not yet 0 sub·thermal X deter· mined

9 X

5.9 X

10) m·2fpulse instead of m·2.s·1 1 1 ) possible.

Util ization nuclear

" 0 " a: � ·;:;

a: ·a. � ·a. .� ; "C .� � Oi ::; Oi � i'i ....J .i! ....1 2 .= ,

X .. ..

.. .. X

device is used if OSI R IS is not

available

X X ..

.. .. Xsl

.. 1 1 ) __ , , , X

.. 1 1 ) __ 1 1 1 X

_g � i

X

..

..

. .

X

x l I

Approx. Number of Exposures per year

500

100 to 130

40 to 50

250 to 300

first tests in May 9 1981 )

� ...... �

.... w cg

Table 5.2 Neutron Radiography Insta l lations in the European Commun ity - Exposure Techniques.

1 1

S1te Fac1l1tY Converters Films Used Track Etch Typical Expos. Used Fi lm Times

Used

Csdarache LDAC Dy or In KODAK · lndustrex .. 2 min. !total time of neutron volley)

Casacc1a TR IGA RC1 In KODAK · Kodirex no 10 . 20 s.

Fontenav- Tr1ton Gadol in 1um KODAK · lndustrex CN80· 15 2 · 20 min. aux -Roses 250 11m and A, M, R,

25 11m mono ·couche

Geesthacht F R G 1 Dy 0,1 mm Structurix CA80 · 15 20 · 60 m in. I n 0,1 mm D4, D2 C/>.80·1 5 B

F R G 2 Dy 0,1 mm Structurix .. 1 5 min . D4

1 k Ci Dy 0,1 mm Structurix CA80· 1 5B 6 h Sb·Be D7 neutron source

Grenoble MELUS INE Gu 2s 11m KODAK · CN80· 1 5 2 min. or MX. M, R 20 min. with

single coated cold neutrons !film Ml

S I LOE Dy 50 11m KODAK · CN80· 15 6 rnin. and 100 11m M and R !f i lm R )

single coated

Harwell D I DO Gd and I n KODAK · l ndustrex KODAK d irect : !Beam foils. Di rect C and S.R. CA80· 1 5B 3 . 60 s . 6HG R9) and transfer I LFORD · SP 352 indirect :

l ine fi lm 5 · 15 min.

D I DO 21 !Beam 6Hl

- - ----....1------

Dark room faci lities available : One laboratory installed within the reactor hal l , near the neutronradiography Install ations. for treatment and duplication of silver·base film,. One laboratory outs1de the reactor. for treatment of nitrate/cel lu lose ·based films and reproductiOn on photographiC paper etc.

2 1

Beam Purity Film Development Special Dark Room Equipment and/or Procedure

Image Quality I bath, temp., time) Indicators

Used

no LX24, Negatoscope 5 min. at 20 °C

VISQI LX24, no room temperature

1 .0. 1 . Manual development 1 1

in vertical troughs. Revelator SOPR ECO : 20 m in; Fixator rapid I LFORD

VI SOl

.. 20 °C, 5 min .

.. etch ing 6h NaOH 50 °C, 30 m in.

Research Fixator Kodak AL4, Enlarger, Contact Reproduction, Chemicals 10 min . at 20 °C, with Light·Box, Profile Projector, VISQI Test thermostatic control. Densitometer and Micro-Object Revelator Kodak LX24,

5 min . at 20 °C, with densitometer.

thermostatic controls.

no " "

not used Standard developer Densitometer to date 20 °c, 4 min .

... �- ---="""'==

Exposure techniques, converters used : Real time dynamic imaging using screens, image intensifier, T.V. Camera and video recorder.

� .... 0

Table 5.2 Contd.

S1te Fac i l i ty Converters Films Used Track Etch Typical Expos. Beam Purity Used Fi lm Times and/or

Used Image Quality I I nd icators

Used

Karlsruhe FR 2 I ndirect, AGFA D2, D4, D7 KODAK 1 h neutron/foil not used with Dy foils Osray eA80· 1 5 1 h foil/07 fi lm

Mol BR 1 25 Jlm Gd Structurix D4 .. 1 5 · 30 min reference (Agfa· Gevaertl fuel pin

BR 2 Dy 0,1 mm Structurix D2, D4 .. 6 · 8 min. V ISQI In 0,1 mm (Agfa·Gevaert)

Petten H F R D y 0 , 1 mm KODAK M KODAK· 16 min. for Dy no (PSF) Kodak BNI and SA eN85 7 min.forCN85

I H F R Kodak BN I and no eA80·1 5 5 min. no iHB8) 93°/oenr. lOB

LFR Gd . 1 00 Jlm Agfa · D7 Yes D7 : 16 min . no KODAK ·SA SA: 120 min.

RISII DR 1 direct : Agfa-Gevacrt KODAK · 30 min. for D 4 ASTM Gd 50 1Jm Structurix D4 Pathe E 545·75 transfer : KODAK · CA80· 1 5B Dy 1 00 1Jm lndustrex SA CN85- IB 90 min. for

eN85 track·etch

Sac lay OS I R IS Dy KODAK · .. 15 min. monolayer (SA 54)

I IS IS transfer : KODAK · lndustrex .. 20 min . I n or Dy M or SR 54

ISIS direct : KODAK CN85 n,a 10s or6L iF

transfer: KODAK SA 54 Dy

Valduc M I A ENE Gd, Dy , In KODAK type A KODAK type M

- - -

3) a) If necessary : foi l (Dy -0 , 1 mm) exposure time : 16 min. transport time of the activated foil to the dark room : 10 min . fa l l transfer on Kodak M f i lm : 35 min. hereafter transfer on Kodak SA film : overnight

.. 3 · 10 min .

I Yes 3 min. 101 , BPI l� b) F i lm development :

5 min. at 20 °e in Kodak DX80 rinsing for 2 min. in running water fixing for 4 min. in Agfa G 334 washing for 20 min. in running water

F i lm Development Special Dark Room Equ ipment Procedure ( bath, temp., time)

-

Developer AGFA G 1 50 no special equipment room temp., 10 min.

procedure as given in .. AGFA-Gevaert manuals)

AGFA G 1 50, 20 °e, 5 min.

3) 13 x 18 em Enlarger

etch ing time 30 min. in NaOH 1 00g/L at 46 °e

13 x 18 em Enlarger

Standard procedure MacBeth Densitometer

X-ray fi lm: 20 °C X·ray Film Producing Tanks hand processing 4 min. and Thermostatic Etches

classic methods for Negatoscope, Profile Projector, x-ray fi lms Contact Reproduction,

. . Enlarger, Densitometer, Polaroid Screens, X·ray Fi lm Process, Thermostatic Etch Bath

..

'

Manual, LX24, Yes 5 · 8 min. at 20 °e

•'"- -""""""" --------.. �

c) Track· etch fi lm : exposure of Kodak eN85 for 7 min. etching t im• 30 min. in NaOH ( 1 00 g/L) at 46 °e all track·etch films are copied on Kodalith 257 1 .

.... � ....

Table 5.3 Neutron Radiography Installations in the European Community. Future Needs and Requirements.

Qual itative Analysis Site Facility

Standards Used In-House Atlas Other

Cadarache LDAC uni rradiated .. .. fuel pins

Casaccia T R I GA RC 1 .. .. ..

Fontenay- T R ITON 1 )

aux- Roses

Geesthacht F R G 1 .. .. ..

F R G 2 ' uni rrad iated -- --fuel and

absorber pins, dummy rigs

1 kCi .. .. .. Sb-Be neutron

I source

Grenoble M E LUS I N E .. Yes ..

S I LOE - - Yes ..

I Harwell D I D O

( Beam 6 H ) not relevant, work too d isparate

D I DO no general �:�-( Beam standards, 6 H G R 9 ) scientific � examination

-��

1 ) Qual itative Analysis :

In most cases, this examination is done by the client. Technical assistance by the S. E.T. is offered only when specifically asked for. Image qual ity can be guaranteed however (well -focused photos without handling traces, chemical pol lution, etc. )

_ _Q<Jantitative Analysis -

Standards Used Profile Projector Microdensitometer Other

.. .. . . . .

.. . . Yes . .

2)

homemade steps .. fast photometer ·-of absorbers G I l l (lucite, Gd-foils) Jenoptik Jena

dummy for -- .. ·-d imensions

. . .. .. --

.. Scanning Densitometer and --Profile Scanning - M icro·

Projector densitometer

pre-irradiation . . .. --picture

not rei evant not relevant not relevant --

.. -· Yes ..

-

2) Quantitative Analysis :

D imensional measurements on ti lm Measurements to determine the materials' homogeneity Use of optical measurement installation, densitometer and m icrodensitometer.

-

-�

... � N

Table 5.3 Contd.

I Qualitative Analysis Site Fac i l ity

Standards Used

Karlsruhe FR 2

Mol BR 1 reference fuel pin conta in ing pel l ets with d ifferent enrich· ment and Pu grains of d i fferent sizes

BR 2 ..

Petten H F R .. (PS F 1 0)

H F R .. ( H B BI

L F R ..

RisGI DR 1 ASTM E 545 . 75

Saclay ORPHEE3

1 I OS I R IS homemade

I dummy rigs IS IS and un·

irradiated fuel and absorber pins

Valduc M I R EN E ..

-----�---- ---- --- -

I n -House Atlas

not in use

..

..

no

no

no

classi fication of defects revealed by neutron radiography

..

..

3) Neutron rad iography installation is being tested at present.

- -

Other Standards Used

..

I .. reference fuel pin conta in ing pellets with d i fferent enrich· ment and Pu grains of different sizes

.. optical micro· meter

no ..

no ..

no ..

.. ASTM E 545 . 75 Calibration fuel pin

.. . .

.. . .

�- --- �-------

Quantitative Analysis - .

Profile Projector

.. I

..

.. I Nikon 6 CT2

"

"

N ikon 6C I ( 1 0x magn.)

Drama 500 ( 1 0x , 20x, 50x) I

..

M icrodensitometer Other l

Joyce· Loeb I .. LTD with Auto·

densidater

. . ..

fast photometer .. V E B Carl Zeiss Jena

no no

no no

no no

Baird double beam Special Cd densi tometer device for

L/d measure· ments

MacBeth quanta log

. . Densitometer

--� - ---- --.-

...... � w

144

Table 5.4 : Neutron Radiography Installations in the European Communities. Future Needs and Requi rements.

Needs and Require-ments in the field of Research and Development

Needs and Require-ments for Practice Guide

Needs and Require-ments for Standards

C - Casaccia F - Fontenay-aux-Roses Ge - Geesthacht Gr - Grenoble

I

[

I

Ge -

K, P, R -K -F, S -

H -F, P, S -

H, Gr -Ge -G r, K, M, P, R -M -M -Ca, M, Gr -p -c -

G r, H -R -

R -

Ce -

M -

p -R -

P, R, F, S -

Gr, M -F, S -

contrast enhancement of images on � track etch films ' track etch technique {improvements) copying nitrocel lulose films reproducibility (density, image quality) image quality I

reduction of inherent scattering in numerous materials (neutron energy, anti-scatter grids) dynamic imaging converters of higher sensitivity technique of dimensional measure-ments epithermal neutron radiography tomography biomedical appl ication general

�ck mh I classification and collection of defects I' revealed by neutron radiography recommended procedures for di rect

1 and transfer methods

I . dimension measurements indicator [ for

a) resolution b) parallaxis

, , c) magnification

development of a universal reference I

fuel pin Ris0 calibration pin calibration standard for dimension measurements 01 indicator for

a} beam quality b) image qual ity

general yes {2x) standard procedures for control and for a Non-Destructive Control Manual '

H Harwell R - R is0 K - Karlsruhe M - Mol P - Petten

S - Saclay V Valduc Ca - Cadarache

ASSEMBLY OR FUEL P INS

-y, n SH IELD I NG

I MAGE CONVERTER ( I n or D y )

145

a .� SHI ELDING

COLLIMATOR

REACTOR I NSTALLATION SCHEME ( LDAC AND CEI)

ROD CONTROL

F ISS I LE SOLUTION ---4-b-L.,-4/

MOBI LE �· R E F LECTOR �·

(BeD)

SCHEME OF LDAC R EACTO R (RAPSO D C E )

P t (PLATINUM) CATALYZER

N EUTRON COLLIMATOR

(POL YTHENE AND Cd)

Fig. 5 . 1 Neutron Radiography Facil ities at CEN Cadarache.

� � � � Lead Graphite Concrete Aluminium

0 20 40 cm

r;==--=11 i----------, .f--------,.,1

/-- -. • ·--- 'A

' ,

. .

Aluminium tube containing fuel pin

.\,·

Slide for In or Dy detectors Hinged frame with In and /or Cd fi lters (open position shown )

• l ' • • •

��7- :.-..;....c -7 ---:· -

Fig. 5.2 Sketch of the Neutron Radiography Facil ity at CNEN-CSN, Casaccia.

-" � en

0 I

, I

10 I

I • ' I . .L

147

WlJJm • m g � Aluminium Steel Lead Brass Stainless

Steel

Lead extractor

--- �1- Lead shielding

-A-......:.---,.----�N-- Aluminium canning tube

Movable shutter for fuel pin replacement

Fig. 5.3 Neutron Radiography I nstallation at CNEN-CSN Casaccia Dual Purpose Transport/ Exposure Container.

::0 0:.0=� 1;: }:.' ::::y�o;·:;: ti�- �00 � 00: · - ... . . . .. . . .

lfil lt RAI L . . '. o.

·: 0. -\ :· .. ·. 0_ .. ::: <0\-\::::'i�}�:i�:ooto� .. :;�:)/� ,u ; · ..... . . · . ..... ·: : · ·, ·: .. ·� -:-. . : · . �.::. ·: ,: :. :·:: ·.� '. ::.· ... � ·:. ·:: ' .. - . · : .. ·· .. � ·r _ :.··. : .� ... -: .. �:: �: �: :·.' · : ·.: ... : �·:;=· � < · : .-· . ... . �_: ·. : ..... : ·._ . .�

I " " I :e .. • •• • • • .t • - 0o . 0 0 0 •. . 0 0 . • 0 .0 PLUG ON .... �AX IAL CHAN N E L �; .'0 ' : .. : ; 0 � ·>. 0 ROLLERS

\�:�;:[;· ·D/;:t<·:<::(;:;i�;;·/<:�::.�.::;>�)J 0 ° , o .' ; : 0 PROTECTION WALL ; :0: . . ', ' : �-:

o • : ', :;. ·: '0 7 , .. 0. " 0'' ' ' •· ···-··j 0 0 0f : · : � ... 0 • 0 . . • TR ITON R EACTOR • • . •• :..·: - · : . : ; 0" · ". 0

I . 0 . :.,:.:·:0:�0:":0:: ·.:>�= :.:�·\>: ;::0_ 0. ':0·�� o�:,o� �. :..\0 :< �- ,• • .

o

. . . .. . . .. · .. · · .

Bi CRYSTAL

POOL

.--- - - l

EXPOSITION ZONE

RAIL AND CA R R IAGE ASSEM BLY FOR PROTECTION D ISPLACEMENT

Fig. 5.4 Neutron Radiography Instal lation at the Axial Channel of the T R ITON Reactor, Fontenay-aux- Roses.

� ,.. IX)

. . •

' . . . J

. • •

� I

" .: ... -=-.L-::·!. : . . � � - -· \ ;. ., ,;..:.......:·:..:.......:...-=---"---� , ,· ;· .. ' '· ' .. , , ,• .. . ·, . . . . I . ' . .

.... .

\

. . . . ,- \� ·, -; · .. . ,, ' . .

.

, \

;'' \ ' , . �I

• \ 't

z 0 i= ...J - ...J (/) UJ � (.) X UJ

._, .; . . . . - · . · - . -... ·.

I • ' • : · ·. · ; • '• :: , •: : �: ·.•: • " 0 •• :• : :. I- I � : '\- I o "' o

149

I •

. . I •

. .

• I

.. �, � ; . . . . . j': • ·' I · : ! ..... ' . . . · . , . ' ' ... · •.

. . . . . .

. ! . . · .

. , · · ' ' ... · ·· · ·· - .. - .. . . . . . • • ' • - . • . . ... -.... � - ,. f ' • • • • • ••

·:�· .. ·. �:-:·.::· ._ ':

- �

. . • , .

.

I • • •

t, i 1• I 11 I t : . . . . I I I II " • 1 I I' t t

' • II I ' I .,. • '· I I I I I I • • I ·, /i 1 I I • ... . ; I •, t · · �· . ;

Qi c: c: � u � � � � � c:: Q) , .s::. x +-' ::I ... co "' > c: ca

.g � "' c: = o !!l u.. "' E L ..

> B .S::. t.l g. gj .... .... g'z

·- o � 1-c:: � C: fe Q) +-' .S::. ::::� .... Q) ,._ z o LO Lri c,

u:::

NEUTRONS

OBJECT

I CAR R I E R

,, .,C. " "; .' . ; •. . . R EACTOR • • @!5 . . ,

CO R R I DO R

�;)�/i\�.�\< ·: .. · . . -... :�·��; �. �-� .. I �->\:/::\ .. • ·. ·;.

PROTECTION WAL L MOB I LE PROTECTION B LOCK

, .. WOR KING ZONE

MOBI LE B EAM AND SUPPORT

Fig. 5.6 Uti l ization Zone of the Neutron Radiography Installation at the TR ITON Reactor, Fontenay-aux-Roses.

..... en 0

BEAM CATCHE R

N EUTRON RADIOGRAPHY CHAM B E R

PARAF F I N S H I E L D I N G

0 •

":>

,.

· ·,p

COLLIMATOR

Fig. 5.7 Beam hole neutron radiography faci lity G E N R A I at the F R G 1 reactor, G KSS Geesthacht.

... en ...

152

A- A section

•

carriage

rectangular ---+--1-11 tube for cassette transport

- - , A . . .

. . ..

. . . . :

. � ·:': 1 ..:·. · b . . \ . .. I ·�· f ·O . ;

··\ " . . · • I . . . .. .

, . . . . . 0 .. 0 ' ·< '

;,• ':·.i

core FRG 2

Fig. 5.8 Neutron radiography underwater facil ity G E N R A I I at the F R G 2 reactor, G KSS Geesthacht.

0 N M r-.

neu tron source ca ssette

i mage recorder _ reflector I Ni l

I Dysprosium screen or track etch foil l I ��:OF/ /////1� I

Beryllium body

Antimony rods ..... en w

neutron shielding

Tl I '· .1 A 1 I I ( poly-ethene and

, < Cd - sheet I . . , .. .

distance holder ' moderator

I poly-ethene I

test object I control rod l

Fig. 5.9 Arrangement for neutron radiography of a control rod in a hot cell, with antimony-beryll ium neutron source at G KSS Geesthacht.

154

ai ::c 0 c: �

(!) .... -0 .... (.) Sl a: w z ::::::l _J w � Q) E

..c: "' .... Q) .... m "' c: c: o e

",t:; '5 .2! Q) ] Z "' Q) c: ..c: - .... � 0 Q. Ol "' c:

g. ·� ·- "' � 0 a: (.) c: ·.p E E ; � � �

F ig. 5.1 1

PNEUMATIC OPERA TI N BEAM C G

SHUTTATCHER

ER

155

Neutron Rad' Beam Shutt

Jography lnstallatio er.

n at the MELU S INE Re actor, Grenoble

. . - ·

{, , , ;; ..

. __ _ .... . .. · --

:.· • i •, . .. ·,:

. ... . , . . . ' ,.; -,· . . · I - " .! ' t .... .

. \ . . . . .. ,- . . I o I

: : \'" . . .. ....

s..- •. I • . . 1-#II j•' .. I CO LLI MATOR

• • I 'C2) I • • I • - ! • " .... .. - . . . . . . ... ., . .. - " .-. • • • " • . .. . • I" .. .

. ... . . . . .. . . . . . . . ··- . . . .. '

S I LOE "35 MW" MAIN POO L

I R RAD IATION DEVICE

D I APH RAGM /CJ 5 mm

� � 2 m 11>1 ooj lt - - �� I

N EUTRON ABSORBING BEAM TUBE ( Cd + Gd + I n + Dy + Au)

IMAGE SIZE :

400 x 1 20 mm

WATERTIGHT GASKET ( ICE O R RUBBER SEAL)

Fig. 5. 1 2 Underwater Neutron Radiography Instal lation for rigs and loops examination at the S l LOE Reactor, Grenoble.

... 8l

D I DO R EACTOR S H E L L WALL

H E L I UM F I LLED B EAM TUBE

B L AND Be F I LTE RS

R EACTOR S H I E LD

�

. I T I

cqR E

It

Fig. 5. 1 3 Vertical Section of the 6 H Cold Neutron Radiography Apparatus a t the D I DO Reactor, A E R E Harwel l .

� U1 .....

1 58

8HGRII

0100 REACTOR FACE B

DOOR :k-- -J . . . . . . - - -, -

I 12110

l_ -WINDOW

REMOIIAIILE

SIDE PLUG 144 Kg)

A) PLAN

LAUE HOLE

i- e�o ..-J I I

REMO\IAIILE TOP

l- I I I TOP OF CASSETTE l c�trr L _ _ _

I 170 mm DIAMETER

1686 I _ . �I.OGRAI'�

I I I IMI6

I I I

15 FT

STEEL F LOOR

LEAD

WALL

B) FRONT ELEVATION

Fig. 5. 14 Schematic drawing of the 6 HG R 9 Neutron Radiography Facility at the D I DO reactor, Harwell.

1 2

1 3

CONCRETE ROOF OF o2o PLANT ROOM

5

1 5 Cassette ports 2 Flask locating ring 3 Removable top shield 4 Reactor face plate 5 Outer steel tank 6 lead shield 7 I nner steel tank 8 Reactor aluminium tank 9 Shield plug (blanking) 1 0 lead window 1 1 Handling tongs 1 2 Removable plugs

8

020

--��r R EACTOR _liUL CO R E

020

21

1 3 lead wal l 14 1 5ft Reactor mezanine . floor 1 5 Pneumatic door 16 Water flooding tube 1 7 Steel rings 1 8 Cadmium disc 1 9 Jabroc rings 20 Col l imator 21 Graphite 22 Concrete

F ig. 5. 1 5 lay-out of the 6 H G R 9 Neutron Radiography I nstallation at the D I DO Reactor, Harwe l l - Side View.

_. CJ1 «)

LEAD S H I E LD I NG

F U E L

160

E LEM ENT -----11,��'-"��-"'l""'r'��

F LOOR OF THE R EACTO R HALL

F U E L ELEM ENT EXCHANGE MACH I N E

""'�"'-"

R EACTOR B LOCK

CO LLIMATOR H EA D W I T H D I APH RAGMS

Fig. 5. 1 6 Neutron Radiography Facility for the F R 2 a t KfK Karlsruhe.

B

161

e CHANNEL WllH FUEL f)·r�-:��;.th�i!/.;;?··;!"e-�!:�·9-"��:y}lij-f!,"�;J·O;j�::.:��}}�0:�"-0��-'):1 0 CHANNEL WllHOUT FUEL !�'=-� � :- 6840 ��l!<;i•,#.'!o¥-:.C. ':P;d�,•"<9 . .;;d�r.:'·��: !��iJ.{1(}Ji� '��[�;��]fjf/:�::�!) S I D E ..,·,:��-q��,�;��j��t�f.:� ;}?-�� .. _. ,-,o . • :·. ·· ·;: "' 'if -' ':'J.-o,··-�·�- . I ::Ji . 'll,•."P•" •'f"-,�i ;-{!lf�.t..(-,,_v.

GRAPHITE

REACTOR CORE

CONCRETE

- D ,;,__,-,;' .. :, -.=�-=-o-:; -�� "' p�-�:0:; CHAN NEL OX 25 ::��:;�-::�:��-��-�� rr .:t' �I'�;; ¢i�f.� v ·; ·,+•Jib:�� ; ' I r- '!J•IJ... ;fl,0;�1:}, NEUTRON RADIO-!;:(•�':i;��:;;�•:- f+ !-+- -£3;g: :!J/;?f.v: GRAPHY ;'· • � • ·.•. ,,·i!-:1 '.:o '>' 1 n· ::t.l,�; -):l, 0 EQUIPMENT AND ,, • ' '· •. , . a" . Y.'"v.-•lf"-.'b..t1 ... � • ';'!-.;,'-"}';"::_.·)'- ..:rti;.i "� ;;;o'bt_il' SHIELDING •; o· • ·.'j:�!.-:, :�;,;�: � • IT l�e}� £?fii• .. �.�-�.::;!(.):·:,, '

- -'� ._:;·�·"',.,,.:.,-;!;�;., '-·'�, .P"-'"";-'l·""',.,.V'-J::...._� -:..:., . .-:;: ;i;:·;!!;:7; rTfl� &,�':.i;,��i�q.;.-;?:�. ·'��:-:� a;,t:}:!...r·. I � I ' I H+tt -.., ... ;, ··��'o•'•· ;· ;._�:! .. �;:�+;�;1..i.::��· J+ J I i§;: � ·�-� .. ��>. .!;;;·�¢.t!,-�tj:r.;,: � "7.�-r�� lt'�,..,.,.�;·.Z'�, ��:(�f;;!�.f-��j�]��/it:�:r.��!�:ti�;;f/?1�:;J1%?i;�� 0��:��

A. GENERAL LAY-OUT

REFERENCE

1500 1300 5 0 8 ·'· 460 500

B. DETAI LED LAY-OUT

-ro.oo

Fig. 5. 1 7 Neutron Radiography Facility a t the B R 1 Reactor a t CEN/SCK, MoL

CORE M I DPLAN E ·

Facility Lb

1 2603 2 2577,5 3 2595 - 2655 4 2605 5 2615

0

28 53,5

0 - 60 81 1 6

162

A. GENE R AL L AY-OUT

I I I Lo --J t4= �----------------- L b------------------�

B. DETAILED L AY·OUT

DETECTION SYSTEM

ONVERTER Dy

Fig. 5.1 8 Neutron Radiography Facil ity at the B R 2 Reactor, CEN /SCK, Mol.

R EACTOR COR E

COLLI MATOR ( R I BB E D FOR

STR ENGTH)

t POOL WATE R

J I I I . . · l i I

F LANGE SEAL

OBJECT HOLDER

CASSETTE SYSTEM

HYD RAU LIC CYLI N D E R F O R MOV I NG COLLI MATOR

Fig. 5. 1 9 Sketch of the underwater neutron radiography instal lation in the pool side faci l ity of the High F lux Reactor, H F R, Petten.

..... Ol w

5

\

1. special container for 4 fuel rods

2. turning device for fuel rods

3. handling tools for special container

4. working gallery

5. collimated neutron beam

6. beam shutter

7. baffle shield

8. central rotation table

9. neutron radiography camera

1 0. vertical channel for special container

with 4 fuel rods

I I . lead shielding column

1 2. biological concrete shielding.

164

3

- ----....:---

Container:

useful length

useful diameter

weight

shielding

2500 mm

235 mm

17.0 t

250 mm lead

Fig. 5.20 "Dry" Neutron Radiography Facility HB8 at H F R Petten.

OBJECT TABLE

TOP-SHI E LDING REACTOR

BORAL -DIAPHRAGM LEAD SH I E LO

GRA P H ITE

VERT. HANNEL

165

0 0 It) C"ll

ELEM.

Fig. 5.21 Col l imator system of the Neutron Radiography Faci lity at the Low Flux Reactor (LFR ), ECN Petten.

1 2 3

4

5

6

7

8

9

Graphite reflector Reactor core Two graphite blocks removed Two neutron beams ( 10x 1 0 cm) lead container for transport and handling of irradiated fuel rods Rod for positioning of fuel rod during radiography Concrete blocks for ·- r � -��JfZA' I radiation shielding -Tube supporting the fuel rod Mechanism for introduction of imaging foils behind the fuel rod to be radiographed

Fig. 5.22 Schematic drawing of the double beam neutron radiography facility at DR 1, Ris0, Denmark.

9/ � Q) Q)

1 Removable precol l imation 2 Ice seal from liquid nitrogen 3 Cassette for converter activation

and film exposure 4 Removable jacks 5 Displacement control 6 Rig container 7 Converter

- � - -

Fig. 5.23 Sketch of the underwater neutron radiography installations, which are used in the IS IS and OSI R I S reactors at CEN, Saclay.

-CD .....

1 Reactor core 2 Removable col l imator 3 Channel through concrete 4 Wel l for fuel penci l carrier 5 Concrete shielding 6 Transport hood 7 Pencil carrier 8 Camera 9 Access pit.

168

6

Fig. 5.24 "Dry" neutron radiography faci l ity at ISIS, CEN Saclay.

BEAM AXIS - · - -

169

_-, ___ r- - -- -J II I• .-! EXTENSION . I C.N.D.

II · · _L_ I I n mo"T'O'

1 .

r CELL

. I SH UTTE

�---1-�-�-=-�-

/j ; · I HALL FOR THE

BEAM TUBES

TAB L E

I ' . I I. ; · / . j _ _ _ _ _ _ _ _ _j

DOOR

LABORATORY FOR MEASUREM ENTS

non-control led working zone

"' "' 1- a: w w .J S: - o � ili

Fig. 5.25 Neutron Radiography Facility at the O R P H E E Reactor, CEN Saclay, General view and Detail of the Exposition Cell and Working Zone.

Core vessel containing the fissi le solution

2 Fixed reflector 3 Mobi le reflector 4 Mobi le reflector raise -

l ower cylinder !5 Core cooling or heating loop 6 Recombining loop 7 Axial collimator 8 Tangent colfimator 9 Storage tank

1 0 Frame 1 1 Caisson 1 2 Biological shield 13 I nspection door 14 Cold water supply 1 5 Exchanger 16 Core heating system 1 7 Control desk 1 8 Specimen transfer glove box 1 9 Glove-box compartment 20 Control led access gates

DE

Fig. 5.26 Schematic drawing of the M I RENE minireactor for Neutron Radiography, Valduc, France.

... �


Nuclear fuel pellets made of processed uranium

http://theconversation.com/how-nuclear-power-generating-reactors-have-evolved-since-their-birth-in-the-1950s-36046


■ωσμ∙Ωπ∆º≠δ≤>ηθφФρ|β≠Ɛ∠ ʋ λ α ρττФ■≠√ ≠≥ѵФ Σ acx

http://www.extremetech.com/extreme/150551-the-500mw-molten-salt-nuclear-reactor-safe-half-the-price-of-light-water-and-shipped-to-order





Other Readings:

http://www.geocities.jp/nekoone2000v/BBS/physical/dose_calculationEnglish.html


Peach – 我爱桃子


Good Luck


Good Luck

Charlie Chong/ Fion Zhanghttps://www.yumpu.com/en/browse/user/charliechong

Understanding neutron radiography reading vii nrhb part 2 of 2

Engineering

charlie chong fion zhang

neutron radiography

motion radiography fluoroscopy

liquid metal https

asnt level

pdm level

asm handbook

radiographic quality