IAEA-TECDOC-1132 XA0053626 , Control assembly materialsfor water reactors: Experience, performance and perspectives Proceedings Technicala of Committee meeting held in Vienna, 12-15 October 1998 INTERNATIONAL ATOMIC ENERGY AGENCY /A February 2000 31-08 J> The originating Section of this publication in the IAEA was: Nuclear Fuel Cycle and Materials Section International Atomic Energy Agency Wagramer Strasse 5 P.O. Box 100 A-1400 Vienna, Austria IAEe Th A doe t normallsno y maintain stock f reportso thin si s series. However, electronic copies of these reports can be obtained from: INIS Clearinghouse International Atomic Energy Agency Wagramer Strasse 5 0 10 x P.OBo . A-1400 Vienna, Austria Telephone: (43) 1 2600-22880 or 22866 Fax: (43 2600-2988)1 2 E-mail: CHOUSE® IAEA.ORG Web site: http://www.iaea.org/programmes/inis/inis.htm Orders shoul accompaniee db prepaymeny db Austria0 10 f o t n Schilling fore a th f m o n s i chequ r credieo t card (MasterCard, VISA). CONTROL ASSEMBLY MATERIALS FOR WATER REACTORS: EXPERIENCE, PERFORMANCE AND PERSPECTIVES IAEA, VIENNA, 2000 IAEA-TECDOC-1132 ISSN 1011-4289 © IAEA, 2000 Printed by the IAEA in Austria February 2000 FOREWORD The safe, reliable and economic operation of water cooled nuclear power reactors depends to a large extent upo reliable nth e operatio f controno l assemblie regulatioe th r s fo shutdowd nan e th f no reactors. These consist of neutron absorbing materials clad in stainless steel or zirconium based alloys, guide tubes and guide cards, and other structural components. Current designs have worked extremely well in normal conditions, but less than ideal behaviour limits the lifetimes of control materials, imposin n economia g c penalty which a stronact s a s g incentiv o product e e improved materials and designs that are more reliable. Neutron absorbing materials currently in use include the ceramic boron carbide, the high melting point metal hafnium and the low melting point complex alloy Ag-In-Cd. Other promising neutron absorbing materials, such as dysprosium titanate, are being evaluated in the Russian Federation. These control materials exhibit widely differing mechanical, physical and chemical properties, which must be understood in order to be able to predict the behaviour of control rod assemblies. Identification of existing failure mechanisms, end of life criteria and the implications of the gradual introduction of extended burnup, mixed oxide (MOX) fuels and more complex fuel cycles constitute firse sth t stesearca n p i improver hfo d material designsd san . earle Inth y par f thio t s decade s recognizewa t i Internationae , th y db l Working Grou Fuen po l Performanc d Technologan e y (IWGFPT) that international conferences, symposi d publishean a d e reviewmaterialth n o s s science aspect f controo s l assemblie r betweenfa d san .werw fe e Consequently, the IWGFPT recommended that the IAEA should rectify this situation with a series of Technical Committee meetings (TCMs) devoted entirel materiale th o yt s aspect f reactoso r control assemblies e interveninth s n e firsheli n 199Th wa d .ti an 3g five years considerable progress ha s been made bringinn I . g together expert materiale th n si s scienc materiald ean s engineerin f controgo l assembly materials, the 1993 meeting and the current one are helping to fill a gap in the information exchange opportunities in this important branch of nuclear research and development. This second TCM, entitled Control Assembly Materials for Water Reactors: Experience, Performance and Perspectives, was held in Vienna from 12 to 15 October 1998. Thirty-one participants from fourteen different countries attended the meeting and nineteen papers were presented and are reproduced in these proceedings together with a summary of the meeting. The IAEA wishee participantth f thano t so l kal r thei fo s r contribution thio t s s publication, which summarizes experience to date with control materials and ongoing research in the field in the participating countries. I.G. Ritchi M.Jd ean . Crijns ,Divisioe botth f ho f Nucleano r Fuel Cycld ean Waste Technology, wer IAEe eth A officers responsibl organizatioe th r efo e meetin e th th f nd o gan compilation of this publication, respectively. EDITORIAL NOTE This publication beenhas prepared from originalthe material submittedas authors.the viewsby The expressed do not necessarily reflect those of the IAEA, the governments of the nominating Member States or the nominating organizations. The use of particular designations of countries or territories does not imply any judgement by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions delimitation ofthe or of their boundaries. The mention of names of specific companies or products (whether or not indicated as registered) does not imply any intention to infringe proprietary rights, nor should it be construed as an endorsement or recommendation partthe IAEA. ofon the CONTENTS Summary .................................................................................................................................................1 LWR control assembly designs historica:A l perspective............................................................................? M. W. Kennard, J.E. Harbottle controR degradatiod PW ro l observes na post-irradiation di n examination Studsvin si k .....................33 T. Jonsson, T. Andersson, L. Bjornkvist Status of control assembly materials in Indian water reactors...............................................................41 V.G. Date, P.O. Kulkarni Calculation modelling of the RCCA movement through bowed FA guide tubes..................................57 Razoumovsky,V. D. Yu.I. Lihkachev, V.M. Troyanov Material operatin controR g behaviouBW l B rodAB s f .....................................................................6ro 5 B. Rebensdorff, G. Bart Experience of CR and RCCA operation in Ukrainian WWER-1000: Aspects of reliability, safety and economic efficiency................................................................77 A. Afanasyev Dysprosiu hafniud man m base absorber advancer sfo d WWER control rods.......................................91 V.D. Risovaniy, A.V. Zaharov, E.P. Klochkov, E.E. Varlashova, D.N. Suslov, A.B. Ponomarenko, ScheglovV. A. Behaviou differenf ro t boron rich solid promisins sa g absorber PWR.........................................10r sfo 3 D. Simeone, Deschanels,X. Cheminant,P. HerterP. Reinforcement against crack propagatio absorberR PW f developmenno y sb t of boron-carbon-hafnium composites....................................................................................... 107 B. Provot, P. Herter NSC KIPT's experienc production ei absorbef no r materials, composited san product contror sfo l mechanism variouf o s s nuclear reactor types ...........................................113 N.P. Odeychuk, V.F. Zelemky, V.A. Gurin, Yu.F. Konotop Damage analysi ceramif so c boron absorber material boilinn si g water reactors and initial model for an optimum control rod management.......................................................121 W. Schulz Fabricatio metallurgicad nan l propertie hafniuf so m alloy contror sfo l rods ......................................153 J.L. Bechade, P. Parmentier Irradiation behaviour of boron carbide in WWER-1000 .....................................................................167 Zakharov,V. A. V.D. Risovaniy, Fridmann,S.R V.B. Ponomarenko, A.O. Poslavskiy WWER-1000 control rod materials: Experience and development.....................................................175 V. Ponomarenko, A. Poslavskiy, A. Scheglov, A. Zaljetniy, V. Risovaniy FRAMATOME contro absorbed ro l r materials: Experienc development...................................19d ean 1 M. Monchanin, X. Thibault Measure of 11 -boron, 10-boron and 7-lithium concentrations in control rods using the nuclear microprobe technique ....................................................................................203 D. Simeone, X. Deschanels, P. Herter The rol claddinf eo g materia performancr fo l controR LW lf eo assemblie s .......................................215 P. Dewes, A. Roppelt BWR control blade replacement strategies..........................................................................................229 M.W. Kennard,J.E. Harbottle High temperature study of the control rod behaviour under accident conditions................................245 V. Troyanov, A. Pomeschikov, V. Sougonjaev, V. Ponomarenko, A. Scheglov List of participants ...............................................................................................................................259 SUMMARY 1. INTRODUCTION For the purposes of this meeting, "control assembly materials" included all of the solid materials used in the construction of control assemblies for the regulation or shutdown of water cooled, power reactors, i.e. neutron absorber(s), cladding, guide tube guidd an s e cards othed an , r structural components of the assembly. Liquid neutron absorbers and poisons were not considered and, wit exceptioe h th pape e on f rn o comparin behavioue gth borof ro n carbide (B4C dysprosiud )an m titanate (Dy203'TiO2) in severe accident conditions, the deliberations dealt with the behaviour of control materials in normal operating and shutdown conditions. International conferences, symposia and published reviews on the materials science aspects of control assemblies have been relatively few and far between. Although