MINUTES OF THE FIRST MEETING OF THE PROGRAMME’S …minutes of the first meeting of the programme’s steering committee iaea, vienna, austria 16-19 may 2000 extrabudgetary programme

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IAEA-EBP-IGSCC-01LIMITED DISTRIBUTION

14-05-01

MINUTES OF THE FIRSTMEETING OF THE PROGRAMME’S

STEERING COMMITTEE

IAEA, VIENNA, AUSTRIA16-19 MAY 2000

EXTRABUDGETARY PROGRAMME ON MITIGATION OF INTERGRANULARSTRESS CORROSION CRACKING IN RBMK REACTORS

INTERNATIONAL ATOMIC ENERGY AGENCY

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1. INTRODUCTION .................................................................................................................. 4

2. WORKING GROUP ACTIVITIES........................................................................................ 4

3. FOR THE ACTIONS ............................................................................................................. 6

Appendix I: STEERING COMMITTEE MEMBERS AND OTHER PARTICIPANTS........... 8

STEERING COMMITTEE MEMBERS ................................................................................ 8

OTHER PARTCIPANTS ..................................................................................................... 12

IAEA SECRETARIAT ......................................................................................................... 13

Appendix II: STEERING COMMITTEE TERMS OF REFERENCE..................................... 14

Appendix III: STEERING COMMITTEE MEETINGS STANDING AGENDA ................... 15

Appendix IV: WORKING GROUPS ....................................................................................... 14

Appendix V: PROGRAMME PROPOSAL ............................................................................. 17

1. BACKGROUND .............................................................................................................. 17

2. PROGRAMME DESCRIPTION...................................................................................... 17

2.1. Improvement in ISI Performance and Qualification .................................................. 18

2.2. Comprehensive Assessment Techniques.................................................................... 19

2.3. Qualification of Repair Techniques ........................................................................... 19

2.4. Decontamination Techniques ..................................................................................... 19

3. DELIVERABLES ............................................................................................................. 19

4. SCHEDULE...................................................................................................................... 20

5. REFERENCES ................................................................................................................. 20

6. PARTICIPANTS .............................................................................................................. 20

Appendix VI: WORKING GROUP 1 ON IMPROVEMENTS IN IN-SERVICEPERFORMANCE AND QUALIFICATION ........................................................................... 21

PROJECT OBJECTIVE ....................................................................................................... 21

Task 1. Transferring Improved Ultrasonic Inspection Techniques for Flaw Detection andCharacterisation................................................................................................................. 21

Task 2. Development of Performance Demonstration Criteria for Ultrasonic Inspection 21

Task 3. Transfer Risk-Informed In-service Inspection Technology.................................. 21

Appendix VII: WORKING GROUP 2 ON COMPREHENSIVE INTEGRITY ASSESSMENTTECHNIQUES ......................................................................................................................... 22

PROJECT OBJECTIVES ..................................................................................................... 22

Task 1. Survey of occurrence of IGSCC in various RBMK Units Damage Data Base. ... 22

Task 2. Deterministic break preclusion procedure including requirements for appropriateISI. ..................................................................................................................................... 22

Task 3. Demonstration of LBB application to 325 mm piping including Leak Rate

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assessment. ........................................................................................................................ 22

Task 4. RBI pilot study for Unit 2 Ignalina NPP............................................................... 22

DAMAGE DATA BASE FORMAT........................................................................................ 22

MINIMUM LEVEL .............................................................................................................. 23

RBI TRAINING COURSE. .................................................................................................. 23

Appendix VIII: WORKING GROUP 3 ON QUALIFICATION OF REPAIR ANDMITIGATION TECHNIQUES................................................................................................. 25

PROJECT OBJECTIVE ....................................................................................................... 25

Task 1. ............................................................................................................................... 25

Task 2. ............................................................................................................................... 25

Task 3. ............................................................................................................................... 25

Task 4. ............................................................................................................................... 25

Appendix IX: WORKING GROUP 4 ON WATER CHEMISTRY ANDDECONTAMINATION TECHNIQUES ................................................................................. 26

Annex I: PROVISIONAL AGENDA....................................................................................... 27

Annex II: PRESENTATIONS HANDOUTS ........................................................................... 30

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1. INTRODUCTION

The first Meeting of the Steering Committee (SC) for the IAEA ExtrabudgetaryProgramme on Mitigation of Intergranular Stress Corrosion Cracking in RBMK Reactors washeld at the IAEA Headquarters in Vienna, Austria, from May 16-19, 2000. The objective ofthe programme is to assist countries operating RBMK reactors in establishing an effectiveprogram to mitigate intergranular stress corrosion cracking (IGSCC) in the austenitic stainlesssteel piping. It is not the objective of the programme to deal with plant lifetime extensionissues. The programme was started in May 2000 by the first Steering Committee Meeting andis to be completed in two years.

The Agenda for the Meeting is provided in Appendix I. Some adjustments to themeeting schedule were made, a presentation by B. Brickstad of DNV, Sweden was movedforward and a presentation by B. Bryce of Mitsui-Babcock, UK was included. Copies of thepresentation materials are provided in Appendix II.

The Meeting was attended by representatives of the participating organizations,including representatives of the RBMK designer, operating organizations, and regulators fromeach country with RBMK reactors. A list of Steering Committee members nominated by theirrespective countries and other participants in the Meeting is provided in Appendix I.

Draft Terms of Reference (TOR) for the Steering Committee were discussed andchanges were proposed. The final Terms of Reference were adopted and are included inAppendix II. In developing the TOR, the Steering Committee recommended to the IAEA thatall reports produced within the programme should be reviewed by the Steering Committee andafter agreement, distributed to participants in the programme. Technical reports should beprepared in both English and Russian, and a unique numbering system should be introduced.

A ‘Standing Agenda’ for subsequent Steering Committee meetings was proposed andadopted by the members. A copy of the Standing Agenda is provided in Appendix III.

The programme includes activities being undertaken by four Working Groups:

Working Group 1 Improvements in ISI Performance and Qualification,Working Group 2 Comprehensive Assessment Techniques,Working Group 3 Repair and Mitigation, andWorking Group 4 Water Chemistry and Decontamination.

The Steering Committee Meeting was structured to provide technical backgroundinformation related to each of these activities, including summary presentations on relatednational and international activities. Appendix IV summarizes the Working Group structureand provides a provisional list of the Working Group participants.

2. WORKING GROUP ACTIVITIES

Preliminary programme plans for each Working Group were discussed. The WorkingGroup (WG) leaders for Working Groups 1, 2, and 3 presented their initial proposal for theWorking Group efforts. Separate proposal was presented summarizing the views of Minatom,Russia. It should be noted, that in general, the initial proposals by the Working Group leaders

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were in agreement or at least consistent with the Minatom, Russia proposals. Based on thesubsequent discussions, the Working Group leaders revised the plans. The revised plans werereviewed by the Steering Committee and were accepted for further refinement andimplementation by the Working Groups.

The Steering Committee agreed that the output of the EBP should be as defined in theProgramme Proposal (Appendix V), respectively, in item 8 of the Steering Committee TOR.

For Working Group 1, one area where there were significantly different interests isrelated to risk-based or risk-informed inspection (RBI). The Russian representatives indicatedthat it would be difficult to apply this approach for the optimization of ISI scope and intervalsat RBMK plants. However, Russian experts will participate in the respective activities (suchas RBI training course). Both the Ukrainian and Lithuanian plant and regulator representativesindicated they wanted to pursue this subject. For this reason, the effort remained part of thework plan, but it is a longer term activity.

For Working Group 2, two areas had significant discussion; the need for a data base ofcracks in the RBMK 300 mm diameter piping and a data base of related laboratory test data,and the availability of a safety assessment that included an evaluation of the limiting loadingand combinations of loading transients. It was agreed that the Working Group 2 leader wouldprovide a table listing the information required for the data base for the Russianrepresentatives to consider. The Ukrainian and Lithuanian representatives agreed to providethe data.

With regard to a safety assessment, the Minatom representative stated that safetyassessments were prepared for each plant as they related to the acceptability for continuedoperation of the cracked pipe. Providing this information to the Steering Committee orWorking Group would have to be discussed with the individual RBMK plant personnel.

For Working Group 3, there were no areas that warranted extended discussions and theproposal from the Working Group leader, as modified by the Minatom proposal, wasaccepted.

At the time of the Steering Committee meeting, a Working Group leader had not beenidentified for Working Group 4. The original scope of Working Group 4 was focused ondecontamination. However, based on interests expressed by the Steering Committee membersand on specific proposals from Japan and Minatom, Russia, the Working Group 4 scope wasexpanded to emphasize water chemistry, with related work on decontamination.

The Scientific Secretary will continue his efforts to identify a leader for WorkingGroup 4, and the membership will be revised to include more Western experts on waterchemistry.

The accepted preliminary work plans for Working Groups 1, 2, 3, and 4 are providedin Appendices VI - IX. These preliminary work plans will be discussed and refined asnecessary by the individual working groups at their first meeting. The revised work plans willbe provided to the Steering Committee before the next meeting of the Steering Committee forfinal review and approval. However, it is expected that the working groups will initiateactions based on the initial work plans and their revision.

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It was agreed that the first meetings of the Working Groups will be held at the RBMKplants. The following proposal was offered by the RBMK plant representatives, pending finalconfirmation and co-ordination of specific meeting dates:

Working Group 1:Kursk plant or Smolensk plant, 10-14.7 or 17-21.7. 2000 1st meeting,11-15.9. or 18-22.9. 2000 the 2nd meeting (training course)*

Working Group 2:Ignalina plant, 7-8.9. 2000, after the RBI course 4-6.9.2000 for theLithuanian, Russian and Ukrainian specialists

Working Group 3:Kursk plant or Smolensk plant, 11-15.9. or 18-22.9. 2000 the 1st meeting *

Working Group 4:Leningrad plant **

* to be specified by E. Brylev, jointly Working Group 1 and 3** to be fixed after Working Group formation

3. FOR THE ACTIONS

The following specific actions were identified.

1. Working Group 1− Working Group leader is to clarify and arrange for the first Working Group meeting to be

held in July, with a training course to be held in September. Meeting specifics to be co-ordinated with the host organization.

− RBMK plant representatives to provide details on access limitations for UT inspection ofwelds.

2. Working Group 2− Working Group leader to provide copy of data base table to RBMK plant representatives

by May 26, 2000.− Russian RBMK plant representatives to provide response on their willingness to provide

requested data by June 15, 2000. Date for providing data will be agreed upon during firstmeeting of Working Group.

− Working Group leader will explore validity, applicability and availability of EDEICdatabase at EPRI

3. Working Group 3− RBMK plants to provide to Working Group leader specific information on welding

equipment, procedures, and joint designs currently used by end of June 2000.− RBMK plants to provide to Working Group chairman information on limiting (maximum

design) stress for various groups of piping locations in downcomer piping and GDH whereweld overlays might be used.

− Working Group leader to assemble relevant background information on weld overlayrepairs and basis for USNRC acceptance of these repairs. This is to be provided at firstWorking Group meeting (September 2000).

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4. Working Group 4− Scientific Secretary to identify a leader for Working Group 4 and to refine membership to

include more Western experts on water chemistry. 5. The Working Groups will outline in detail outputs, priorities and specify near and long

term actions (both within the 2 years duration of the EBP) during the first meeting of eachWorking Group .

6. Several Steering Committee members mentioned that the funding of the work

recommended by the Working Groups and the Steering Committee should be considered.It is proposed to address this at the second Steering Committee meeting in December 2000by which time the work needed will be more clearly identified.

7. The Scientific secretary should determine the appropriate distribution of meeting minutes

and other information to be prepared in the frame of the programme in line with the IAEApractices. The Steering Committee recommends as wide as possible distribution.

8. Steering Committee members will provide the personal data of Working Groups members

from their countries/organizations (address, telephone, fax, email), to the IAEA by June 52000.

The next meeting of the Steering Committee will be held in Vienna, December 5-72000.

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Appendix I

STEERING COMMITTEE MEMBERS AND OTHER PARTICIPANTS

STEERING COMMITTEE MEMBERS

JAPANMr. Susumu ShibuyaFugen Nucler Power StationJapan Nuclear Cycle Development Institute3, Myojin-cho, Tsuruga-shi, Fukui-ken914-8510 JapanTel.: +81 770 26 1221Fax: +81 770 26 8125E-mail: [email protected]

LITHUANIAMr. Gytis MaksimovasPermanent Mission of LithuaniaLöwengasse 47/1/Top 8A-1030 ViennaTel.: +43 1 710 9780Fax: +43 1 710 9759E-mail: [email protected]

Mr. Gennady NegrivodaIgnalina NPP4761 VisaginasLithuaniaTel.: +370 66 31244Fax: +370 66 29350E-mail: [email protected]

RUSSIAN Ms. Inna KaliberdaGosatomnadzor, SEC NRSAutozavodskaya str. 14/23MoscowRussiaTel.: +7 095 277 4001Fax: +7 095 275 5548E-mail: [email protected]

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RUSSIANMr. Evgeny BrylevConcern "Rosenergoatom"P.O. Box 912101000 MoscowRussiaTel.: +7 095 220 6647Fax: +7 095 239 2553

Mr. Oleg TchernikovLeningrad NPPLeningrad regionSosnovy Bor,188537RussiaTel.: +7 812 69 1397Fax: +7 812 69 2518E-mail: [email protected]

Mr. Anatoly PETROVNIKIET/RDIPEP.O. Box 788101000 MoscowRussiaTel.: +7 095 263 74 29Fax: +7 095 975 20 19E-mail: [email protected]

SWEDENMr. Ervin LiszkaSwedish International Project Nuclear SafetyKlarabergsviadukten 90Box 70283StockholmS-10722 SwedenTel.: +46 8 698 3082Fax: +46 8 20 9895E-mail: [email protected]

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SWEDENMr. Bjorn BrickstadDet Norske Veritas (DNV)Fracture Mechanics, Technical ConsultingWarfvinges väg 19BBox 30234Stockholm10425 SwedenTel.: +46 8 587 940 57Fax: +46 8 651 70 43E-mail: [email protected]

UKRAINEMr. Vadim GryshchenkoState Nuclear Regulatory AdministrationArsenalna str. 9/11KievUkraineTel.: +380 44 254 33 64 or 380 44 254 33 47Fax: +380 44 254 33 11E-mail: [email protected]

Mr. Yuriy NeretinChernobyl NPPSlavutych, Kiev. Obl.255190 UkraineTel.: +380 44 934 3109Fax: +380 44 792 6314E-mail: [email protected]

USAMr. Michael Mayfield SC ChairmanU.S. Nuclear Regulatory CommissionDivision of Engineering TechnologyMail Stop T10-D20Washington, DC 20555USATel.:+1 301 415 5678Fax:+1 301 415 5074E-mail: [email protected]

Mr. Adrian RobertsBattelle2309 SW 1st AV. #745Portland, OR 97201USATel.:+1 503 464 9037Fax:+1 503 464 1017E-mail: [email protected]

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Mr. Tom Taylor Leader WG 1Pacific Northwest National Laboratory (PNNL)902 Battelle Boulevard2400 StevensMail Stop K5-26Richland, WA 99352USATel.:+1 509 375 4331Fax:+1 509 375 6736E-mail: [email protected]

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USAMr. Jack Lance Leader WG 3Electric Power Research Institute (EPRI)Non-Destructive Evaluation Center1300 WT Harris Blvd.Charlotte, NC 28262USATel: +704 547 6063Fax: +704 547 6109E-mail: [email protected]

OTHER PARTCIPANTS

RUSSIA Ms. Ludmila MelnikovaRDIPEP.O. Box 788Moscow 101000Russian FederationFax: +7 095 263 21 80E-mail: [email protected]

SWEDEN Mr. Adam LetzterDet Norske Veritas (DNV)Fracture Mechanics, Technical ConsultingBox 30234Stockholm10425 SwedenTel.: +46 8 587 94 281Fax: +46 8 651 70 43E-mail: [email protected]

UK Mr. Laurence PoulterAEA TechnologyRD3 Risley, WarringtonWA3 6AT United KingdomTel.: +44 192 525 4255Fax: +44 192 525 4629E-mail: [email protected]

Mr. Bill BryceMitsui Babcock Energy LimitedPorterfield RoadRenfrew PA4 8DJScotlandTel: + 44 141 885 3314Fax: + 44 141 885 3379E-mail: [email protected]

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IAEA SECRETARIAT

Ms. Annick Carnino. DIR-NSNIMr. Luis Lederman, NSNIMr. Radim Havel, NSNI

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Appendix II

STEERING COMMITTEE TERMS OF REFERENCE

The objective of the IAEA Extrabudgetary Programme is to assist countries operatingRBMK reactors in establishing an effective programme to mitigate the IGSCC in austeniticstainless steel piping. It is not the objective of the programme to deal with plant life extensionissues.

The Steering Committee of the Programme provides guidance on its implementation.The role of the Steering Committee is in particular:

1. to advise the IAEA on programme implementation and recommend related actions;2. to monitor the programme progress achieved, collect, co-ordinate, and assimilate the

results of projects (Working Groups) addressing specific aspects of the problem, andpromote practical implementation of programme results at the national level;

3. to provide a forum for the exchange of information on related work underway and plannedand to advise the IAEA on matters requiring co-ordination with the national, bilateral andinternational activities;

4. to collect and evaluate information about safety assessments implemented for RBMKplants applicable to IGSCC and to review all reports prepared in the frame of theprogramme;

5. to assure that the efforts of the Working Groups and of the programme as a whole remainfocused on safe operation of RBMK plants;

6. to assure that the efforts of the Working Groups span the full spectrum of technical issuesthat provide a reasonable basis for addressing the fundamental safety issue raised byIGSCC;

7. to assure that recommendations take full account of radiological dose considerations;8. to provide a final report describing methods for managing IGSCC in RBMK reactors.

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Appendix III

STEERING COMMITTEE MEETINGS STANDING AGENDA

DAY 1

Review Minutes of the Previous Steering Committee Meeting

Update on RBMK IGSCC Related Status�� Lithuanian,�� Russian,�� Ukrainian.

Technical Presentations and Discussions�� Specific topics of interest to Steering Committee on IGSCC, repair, mitigation, safety

assessment, etc.

DAY 2

Presentations of Working Group Leaders

1. Summary of actions and meetings since last Steering Committee meeting.2. Status of actions in work plan.3. Plans/schedule until next Steering Committee meeting:

�� schedule for specific actions of meetings,�� individuals responsible for actions.

DAY 3

Steering Committee Discussions

1. Discussion on status and plans for Working Groups:�� identify any problem areas that warrant attention for Working Groups or

the IAEA,�� provide suggestions or recommendations to the Working Groups.

2. Discussion on specific Steering Committee actions including presentations fromresponsible Steering Committee member.

3. Agree on status report to the IAEA and funding organizations.

Appendix IV

WORKING GROUPS

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Improvements in ISIPerformance andQualification

T.Taylor, PNNL

T. Trelinski, …., Canada

B.J. Dikstra, Mitsui Babcock

J. Saburov, Ignalina NPP

V. Bykov, Leningrad NPP

A. Miasniankin, Kursk NPP

V. Stasenko, Kursk NPP

V. Galberg, Kursk NPP

P. Nikishov, Smolensk NPP

A. Arefiev, NIKIET

N. Timofeev, NIKIET

I. Korobskaya, GAN

S. Kostenko, NRA

I. Kadenko, ChNPP

V. Vanjukov, Minatom

Comprehensive AssessmentTechniques

B. Brickstad, DNV

H. Schaefer, GRS

R. Kilian, Simens

A. Letzter, DNV

Yoshitsugu Morishita, ICTDC

W. Koo, US NRC

L. Poulter, AEAT

J. Saburov, INPP

A. Petrov, Leningrad NPP

A. Parshin, Smolensk NPP

S. Polyanskikh, Kursk NPP

A. Arzhaev, NIKIET

V. Kiselyov, NIKIET

V. Aladinsky, INSC

V. Torop, UIDP

V. Chugunov, ChNPP

N. Karpunin

Qualification of RepairTechniques

J. Lance, EPRI

N. Ivanov, INPP

V. Apoutine, Smolensk NPP

Y. Zakharzhevsky, LNPP

S. Kharakhnin, LNPP

G. Saprykine, NIKIET

V. Tonkikh, ChNPP

V. Makhanev, INSC

L. Keblas

I. Sivokhin, NTC

Water Chemistry andDecontamination Techniques

U. Staudt, VGB

T. Kitabata, Fugen NPP

A. Oryshaka, INPP

V. Tishkov, Leningrad NPP

P. Kochan, Smolensk NPP

V. Belous, NIKIET

V. Zabolotnykh, ChNPP

V. Yumanov, VNIIAES

L. Denisova, NTC

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Appendix V

PROGRAMME PROPOSAL

1. BACKGROUND

The safety basis for RBMK reactors follows generally used safety principles of “defencein depth”. In-service inspection has revealed widespread intergranular stress corrosioncracking in the safety related austenitic piping of the main circulation circuit in RBMKreactors. IGSCC in the safety related main circulation circuit piping of RBMK reactorsincreases the probability of core damage due to pipe break. Therefore, IGSCC in RBMKreactors is an important safety issue.

Operators of BWR reactors in western countries experienced a similar problem startingin the late 1970’s. As a consequence, successful strategies for managing IGSCC degradationin BWR reactors were developed. Design differences between BWR and RBMK reactorspreclude the use of BWR strategies without adapting the technology to the RBMK case.

Recognising the importance of this issue the IAEA organized a Workshop on“Environmental Assisted Cracking of NPP Austenitic Stainless Steel Piping” [1] andsubsequently an experts’ meeting on this issue specifically for RBMK reactors [2] in 1998.Experts who participated concluded that a comprehensive programme is needed to address theissues of IGSCC in all RBMK reactors. The experts meeting in October 1998 developedproject outlines for seven technical areas that were felt necessary to address IGSCC in RBMKdesigned reactors. To co-ordinate the efforts of these projects the IAEA convened the firstmeeting of the most general and broadest scope group, the Safety Assessment Group with theobjective to advise on the overall programme planning, co-ordination and prioritisation.

2. PROGRAMME DESCRIPTION

The seven projects needed to mitigate the impact of IGSCC on safe operation of RBMKreactors were identified in October 1998 [2] as:

− Safety Assessment− Improvement of In-service Inspection Techniques− In-service Inspection Systems Qualification− Leak Detection Systems− Comprehensive Integrity Assessment− Repair Techniques− Decontamination

The interdisciplinary nature of this programme requires a Steering Committee to co-ordinate and focus programme activities and to integrate the results of other projects whenapplicable.

The role of the Steering Committee of the programme should be as follows: 1. monitor the progress achieved, collect, co-ordinate, and assimilate the results of

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projects addressing specific aspects of the problem, promote practicalimplementation of project results;

2. collect and evaluate information about safety assessments implemented for RBMKplants applicable to IGSCC;

3. assure that the efforts of the project groups remain focused on viable alternatives toaddress the key safety requirements;

4. assure that the efforts of the project groups span the full spectrum of technical issuesthat provide a reasonable basis for addressing the fundamental safety issue raised byIGSCC;

5. assure that recommendations take full account of dose considerations;6. provide a report describing methods for managing IGSCC in RBMK reactors.

The Steering Committee would meet according to the needs of the programme. TheIAEA would serve as the facilitating agent and programme administrator.

The Steering Committee should be composed of representatives from RBMK regulators,operators, designer and other countries directly involved in the programme. Project grouprepresentatives would participate in steering committee meetings when appropriate.

The review of the project outlines developed during the October meeting led tocombination of several projects that contained common goals, without changing the technicalscope of the overall programme. The proposed programme for mitigating the consequences ofIGSCC in RBMK main circuit coolant piping now contains four projects as illustrated in Fig.1. The Figure illustrates the type of work that would be performed under each project. Thespecific objectives of each project are described below.

A detailed description of the total technical scope of the programme may be found in thereport of the October meeting [2].

2.1. Improvement in ISI Performance and Qualification

This project achieves two objectives. The first objective is to improve the in-serviceinspection technology used to detect and monitor IGSCC. Successful completion of thisobjective includes:

− Improving inspection technology used to detect and assess cracking in piping beforeapplying repair technology.

− Improving inspection technology used to monitor the effectiveness of repair technology.

The second objective is to develop in-service inspection qualification processes thatensure the conduct of in-service inspection activities meets minimum reliability requirementsfor reducing the probability of pipe failure. The minimum reliability guidelines will bedeveloped by the Comprehensive Assessment Techniques project.

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2.2. Comprehensive Assessment Techniques

This project achieves the following objectives.

− Develops an understanding of the causes leading to different levels of damage in plants.− Develops an understanding of the crack initiation and propagation processes for austenitic

piping in RBMKs, including investigation of initiating events and system transients− Develops information on crack growth rates which will influence in-service inspection

intervals− Develops reliability requirements for in-service inspection techniques. This objective will

affect the design of ISI qualification processes.− Assesses existing leak detection capability, considers feasibility and determines

requirements for leak detection systems capable of providing early warning of throughwall cracking.

2.3. Qualification of Repair Techniques

This project achieves the following objective.

− Evaluates current weld repair technology for application to RBMK piping.− Develops procedures for qualifying weld repair technology

2.4. Decontamination Techniques

This project achieves the following objective.

− Provides an optimal process for decontaminating main circuit piping which will reduce theradiation dose during ISI and weld repair activities.

− Assess the affect of decontamination processes on the initiation and growth of IGSCC.

3. DELIVERABLES

The deliverables for this programme include the following:

− Technology transfer of improved ISI techniques and procedures for detecting andmonitoring IGSCC

− Requirements for training and qualification of in-service inspection personnel− Technology transfer of qualified weld repair technology for RBMK reactors− A report that provides guidance for managing the safety aspects of IGSCC mitigation. The

report will address the following topics: (1) potential changes to the materials, stresses,and environment; (2) improvements in in-service inspection equipment and proceduresreliability, inspection strategies, and leak detection systems to provide early detection ofcracking or the development of leaks; (3) potential changes in system design orconfiguration to mitigate the effects of pipe breaks; and (4) potential repair strategies forcracking that has been detected. (5) A Guide for the technical topics and quality assurancerequirements to be addressed in the safety assessment report for managing IGSCC. (6)Recommendations for decontamination

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4. SCHEDULE

Leakage due to IGSCC in RBMKs has been minimal but inspections have shownextensive crack initiation so it is important to establish improved IGSCC managementprogrammes in RBMK reactors quickly. Accordingly, the programme is expected to completea report on guidance for mitigating the safety impact of IGSCC in austenitic stainless steelpiping within two years of initiation. In parallel, as appropriate methods and criteria aredeveloped, the programme will facilitate implementation of these technologies at the powerplants by conducting training and mentoring programmes conducted by the same projects thathave developed the guidelines. The evolution from safety criteria development to training andmentoring will differ between projects. Moreover, the Steering Committee will issue periodicprogress reports to ensure early communication of important results to member states. Theinitial schedule is based on effort estimates made at the October 1998 meeting [2]. Theschedule assumes that effort is not delayed by funding or contracting limitations.

Discussions between RBMK regulators, RBMK designers and western experts inIGSCC issues have limited the proposal to those projects that most experts agreed would havea significant potential for application to IGSCC management in RBMKs. A continuingfunction of the Steering Committee will be to monitor and adjust priorities based on feedbackfrom participants and other constraints that may arise.

5. REFERENCES

[1] Report of a Regional Workshop on Environmentally Assisted Cracking of NPPAustenitic Piping held in Slavutych, Ukraine, June 1998, TC Project RER/9/052, IAEA,Vienna, 1998.

[2] Expert’s Discussion on Follow-up Activities on IGSCC of RBMK ReactorsAustenitic Stainless Steel Piping, TC Project RER/9/052, IAEA-TC-8141, IAEA, Vienna,1999.

6. PARTICIPANTS

G. Maksimovas - VATESI, LithuaniaI. Sivokhine - GAN, RussiaA. Potapov - RDIPE, RussiaL. Melnikova - RDIPE, RussiaV. Hryschenko - NRA, UkraineN. Steinberg - Atomaudit, UkraineR. Havel - Czech RepublicD. Jungclaus - GRS, GermanyE. Liszka - SIP, SwedenP. Tipping - SFNSI, SwitzerlandL. Poulter - AEA Technology, UKM. Mayfield - NRC, USAT. Moran, - ANL, USAT. Taylor, - PNNL. USA

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Appendix VI

WORKING GROUP 1 ONIMPROVEMENTS IN IN-SERVICE PERFORMANCE AND QUALIFICATION

PROJECT OBJECTIVE

The objective of the In-service Inspection Performance and Qualification WorkingGroup is to co-operate with Lithuanian, Russian and Ukrainian NDE specialists to improvethe reliability of ultrasonic inspection techniques for detection and characterisation ofintergranular stress corrosion cracking in austenitic piping in RBMK designed reactors.

The project objective will be accomplished by completing the activities in the followingtasks.

Task 1. Transferring Improved Ultrasonic Inspection Techniques for Flaw Detection andCharacterisation

The objective of this task is to transfer ultrasonic inspection techniques to NDEspecialists at RBMK reactors that will improve the reliability of detecting and characterisingthe length and through wall extent of IGSCC. The scope of subject matter that will betransferred as part of this task will include the following topics.

− Transfer to RBMK NDE specialists procedures for flaw detection and sizing in weldoverlays

− Exchange experience with international experts on ultrasonic inspection of welds withlimited access. This exchange will include a discussion of commercially availablecomputer simulation and modelling tools that are available to aid inspection techniquedevelopment.

− Development of a common inspection procedure for 300 mm diameter piping and trainingNDE specialists on the procedure.

Task 2. Development of Performance Demonstration Criteria for Ultrasonic Inspection

The objective of this task is to develop practical performance demonstration criteria forultrasonic inspection of austenitic piping in RBMK designed reactors. The performancedemonstration criteria will include manual, semiautomatic, and automatic ultrasonicinspection techniques.

Task 3. Transfer Risk-Informed In-service Inspection Technology

The objective of this task is to transfer Risk Informed In-Service Inspection (RIISI)Technology to RBMK operators. The task objective will be accomplished by conducting aseminar that teaches the fundamental aspects of RIISI. Incorporation of RIISI methodology inLithuanian, Russian and Ukrainian approaches will be the choice and responsibility ofindividual countries.

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Appendix VII

WORKING GROUP 2 ONCOMPREHENSIVE INTEGRITY ASSESSMENT TECHNIQUES

PROJECT OBJECTIVES

The objectives of the Comprehensive Integrity Assessment Techniques Working Groupare as follows:

− To propose routines for assessment of integrity of the Ø325 mm piping of RBMK MCCmaintaining safe operation in respect of pressure boundary;

− To exchange/transfer knowledge concerning methods for managing the IGSCC;− To perform a pilot study of RBI applicability to the Ø325 mm piping of RBMK MCC.

The working group objectives will be addressed by the following tasks:

Task 1. Survey of occurrence of IGSCC in various RBMK Units Damage Data Base.

Collection of data important to improve understanding of IGSCC as a degradationmechanism in RBMK plants. The scope of data base is illustrated in the attached Data baseformat.

Obtained data will be used as a basis for work in Tasks 2.0 and 3.0.

Task 2. Deterministic break preclusion procedure including requirements for appropriateISI.

− Methods for assessment of acceptable crack-size.− Assessment of combination of detectable crack-size and inspection interval.

Task 3. Demonstration of LBB application to 325 mm piping including Leak Rateassessment.

− Practical demonstration of LBB concept application to 325 mm piping.− Evaluation of expected leak rates for detectability requirements on leak detection system.

Task 4. RBI pilot study for Unit 2 Ignalina plant

− Probabilistic optimisation of ISI.− Demonstration of RBI methodology as an “intelligent” tool for evaluation and comparison

of different measures for managing of IGSCC risk.

DAMAGE DATA BASE FORMAT

The following data should be presented for each detected defect:

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MINIMUM LEVEL

1. Plant/ Unit2. Pipe system and location, (weld ID)3. Year of detection4. Pipe dimension, (outer diameter, thickness)5. Defect’s size (length, depth if possible)6. Orientation (axial, circumferential, circumferential position, multiple defects?)7. Detection Technique (type of probe)8. Sizing Technique9. Type of weld (fabrication or assembly weld)10. Weld geometry11. Material (base material, weld material)12. Chemical composition of base material (C, Ti, ….)13. Operating temperature14. Suspected cause of defect15. Earlier history (same defect detected during earlier inspection?, any weld repair?, etc.)

DESIRED LEVEL

16. Verified cause of defect (IGSCC, TGSCC, Fatigue, etc. preferably by metallograficexamination)

17. Water chemistry conditions (oxygen, conductivity, electrochemical potential, etc.)18. Welding procedure (heat input during welding, number of passes)19. Local weld geometry (e.g. local thickness discontinuity)20. Radiation dose during one inspection (mSv)21. Other type of information (e.g. repair method)

RBI TRAINING COURSE.

This includes a 3-day course (in English) on Risk Based Inspection and it’s practicalapplications to be held at Ignalina NPP September 4 to 6, 2000. The course is aimed forLithuanian, Russian and Ukrainian participants only and will give insights of the theory andapplications of RBI for nuclear piping components and how these procedures can be used tooptimise both the selection of components to be inspected and the length of the inspectionintervals. The course will contain the following items:

I. General information on RBI-procedures for Nuclear Power PlantsII. Damage mechanismsIII. Basic elements of mathematical statisticsIV. Mathematical basis of reliability analysisV. Monte Carlo and FORM methodsVI. Software for Probabilistic Fracture Mechanics, PFMVII. PSA and consequence analysesVIII. Evaluation of riskIX. Risk ranking proceduresX. Definition of a risk based inspection programXI. Application on Nuclear Power Plants

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XII. Exercises of PFM and risk evaluations using PFM software

The participants of the training course should have a basic knowledge of fracturemechanics. Also, there will be no time for translation between English and Russian.Therefore, the participants should have a good understanding of the English language.

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Appendix VIII

WORKING GROUP 3 ONQUALIFICATION OF REPAIR AND MITIGATION TECHNIQUES

PROJECT OBJECTIVE

To provide qualified technology to the RBMK NPPs to repair piping with existingcracks and to mitigate cracking in uncracked welds.

Task 1.

To recommend optimised welding technology for use in the repair and replacement ofwelded joints in the RBMK piping systems effected by cracking.

1.1. Development of information related to the techniques and equipment currently availableto the RBMK operators.

1.2. Provide specific qualified welding procedures for the new weld joints used to repairwelds of cracked piping systems.

1.3. Provide specific welding procedure for repair that involves a new section (new material)of pipe attached to the existing piping.

Task 2.

To recommend optimised overlay welding technology for use in the repair of crackedwelds and for mitigation of uncracked but sensitised weld joints in the RBMK piping systems.

2.1. Development of information related to the techniques and equipment currently availableto the RBMK operators.

2.2. Transfer of weld overlay experience and technology to RBMK NPPs.2.3. Support qualification of weld overlay procedures and operators, using existing plant

equipment were applicable.

Task 3.

To recommend improved technologies that may be applied on RBMKs in a cost-effective manner.

Task 4.

Qualification of the mitigation technologies.

4.1. To resolve issues related to the application of the mitigation technologies on thepotentially flawed welds.

4.2. Establish qualified methods to apply Mechanical Stress Improvement Processes (MSIP)and weld overlay for stress improvement.

Note: For the purpose of these tasks a welding procedure shall include specifying equipment,process parameters, weld joint design, weld materials specifications and all essential variablesrequired by the applicable standards.

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Appendix IX

WORKING GROUP 4 ONWATER CHEMISTRY AND DECONTAMINATION TECHNIQUES

The Workplan is being developed. The Working Group meeting is planned to be held on October16-20 2000 at Leningrad plant.

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Annex I

FIRST STEERING COMMITTEE MEETING

Date: 16 - 19 May 2000

Venue: Room C07 VI, IAEA Headquarters, Vienna, Austria

PROVISIONAL AGENDA

16 MAY 2000, TUESDAY

10:00Opening: A. Carnino

10:15Adoption of Agenda: M. MayfieldChairperson’s remarksSteering Committee Terms of Reference

10:45Programme objective and proposed approach: R. Havel

11:10Coffee break

11:30Measures to ensure safe operation of austenitic: A. Petrov300 mm diameter pipelines at Russian NPPs withRBMK reactors

12:30Lunch break

14:00IGSCC problem in austenitic 300 mm diameter: G. Maksimovaspiping of Ignalina plant reactor, current: G. Negrivodaimprovements

14:30Study of stability of multiple forced circulation: I. Kaliberdacircuit of RBMK NPPs and assessment ofsignificance and effects of factors on damages ofaustenitic pipelines

15:00Safety improvements programme at Leningrad plant: O. Tchernikov

15:30Coffee break

16:00Technical measures to mitigate IGSCC damage: E. Brylevof austenitic pipelines at Russian NPPs

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16:30Status report on Unit 3 of Chernobyl plant: V. Gryshchenko

17:00Chernobyl plant experience: Y. Neretin

17:30Adjourn

17:45Reception, VIC Restaurant

17 MAY 2000, WEDNESDAY

Related International/Bilateral Activities and Experiences Accumulated inOther Member States

9:30 Japanese bilateral programmes: S. Shibuya

9:50 Countermeasures against stress corrosion: S. Shibuyacracking for the Fugen plant

10:30The ubiquitous nature of stress corrosion: A. Robertscracking in light water reactor materials

11:00Coffee Break

11:30Swedish bilateral activities and national: E. Liszka,experience with IGSCC: A. Letzter, B. Brickstad

12:00UK bilateral programmes and other activities: L. Poulterrelevant to RBMK IGSCC

12:30Lunch Break

Working Groups’ Objectives and Tasks

14:00In-service inspection: T. Taylor

14:30Comprehensive integrity assessment techniques: A. Letzter

15:00Qualification of repair techniques: J. Lance

15:50Coffee Break

16:20Decontamination techniques

16:50Discussion

17:30Adjourn

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18 MAY 2000, THURSDAY

9:30 Discussion on Working Groups tasks, work plan andcomposition

10:45Coffee Break

11:15Discussion continued

12:30Lunch Break

14:00Consolidation of Working Groups tasks and work plan(in groups)

17:30Adjourn

19 May 2000, Friday

9:30 Consolidation of Steering Committee recommendations

10:45Coffee Break

11:15Organizational matters

12:30Closing remarks

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Annex II

PRESENTATIONS HANDOUTS