XA9745920 IAEA-TECDOC-962 Small reactors with simplified design Proceedings Technicala of Committee meeting held in Mississauga, Ontario, Canada, 15-19 May 1995 INTERNATIONAL ATOMIC ENERGY AGENCY November 1997 t 29 The IAEA doe t normallsno y maintain stock f reportso thin si s series. However, microfiche copie f thesso e reportobtainee b n sca d from ClearinghousS I N I e International Atomic Energy Agency Wagramerstrasse5 0 10 x P.OBo . A-1400 Vienna, Austria Orders should be accompanied by prepayment of Austrian Schillings 100,- fore for e chequa th mf th IAEmf o n o i n i r Aeo microfiche service coupons orderee whicb y dhma separatel ClearinghouseS I y N froI e mth . IAEA-TECDOC-962 Small reactors with simplified design Proceedings Technicala of Committee meeting held in Mississauga, Ontario, Canada, 15-19 May 1995 W INTERNATIONAL ATOMIC ENERGY AGENCY originatine Th g Sectio thif no s publicatio IAEe th Ann i was: Nuclear Power Technology Development Section International Atomic Energy Agency Wagramerstrasse5 P.O. Box 100 A-1400 Vienna, Austria SMALL REACTORS WITH SIMPLIFIED DESIGN IAEA, VIENNA, 1997 IAEA-TECDOC-962 ISSN 1011-4289 ©IAEA, 1997 Printe IAEe th AustriAn y i d b a November 1997 FOREWORD There is a potential future need for small reactors for applications such as district heating, electricity productio t remotna e location desalinationd an s . Nuclear energn ca y provide an environmentally benign alternative to meet these needs. For successful deployment, small reactors must satisf e requirementth y f userso s , regulatore th d an s general public. The IAEA has been following the developments in the field of small reactors as a part sub-programme oth f advancen eo d reactor technology accordancn I . e wit intereste hth f so Member States, a Technical Committee meeting (TCM) was organized in Mississauga, Ontario, Canada, 15-1 199y 9 Ma 5 discuso t statue sth designf so desigd san n requirements related to small reactors for diverse applications. The papers presented at the TCM and a summary of the discussions are contained in this TECDOC which, it is hoped, will serve the Member States as a useful source of technical information on the development of small reactors with simplified design. EDITORIAL NOTE In preparing this publication press,for IAEAthe staffof have pages madethe up from the original manuscripts submittedas authors.the viewsby The expressed necessarilynot do reflect those of the governments of the nominating Member States or of the nominating organizations. Throughout the text names of Member States are retained as they were when the text was compiled. Theof use particular designations countriesof territoriesor does imply judgementnot any by publisher,the legalthe IAEA, to the status as of such countries territories,or of their authoritiesand institutions or of the delimitation of their boundaries. The mention of names of specific companies productsor (whether indicatednot or registered)as does implyintentionnot any infringeto proprietary rights, should construednor be it an as endorsement or recommendation on the pan of the IAEA. The authors responsibleare havingfor obtained necessarythe permission IAEAthe to for reproduce, translate or use material from sources already protected by copyrights. CONTENTS Summary .................................................7 . Small reactor operating mode ...................................... 19 V.G. Snell Small nuclear reactor safety design requirements for autonomous operation .......... 27 K.S. Kozier, KupcaS. New safe kinreactort firsa f no do tt engineerinbu , g .......................9 4 . M. Nurdin A nuclea fivW eM r heating reactor ..................................7 5 . Thong Dqfang, Dong Duo, Su Qingshan Safety concept and operation control approach in the design of small nuclear reactors .... 69 Yu.D. Baranaev, Yu.I. Orekhov, Yu.A Sergeev, N.I. Sosnin, K. V. Zverev Safety objectives and design criteria for the NHR-200 ....................... 75 Dazhi Xue, Wewciang Zheng Technical outUne of a high temperature pool reactor with inherent passive safety features ...................................... 83 R.S. Hart Appendi : xI Desig developmend nan t statu smalf smediuo d lan m reactors 1995 ....9 .10 M.A. Al-Mugrabi Appendi : PublixII c acceptanc smalf eo l reactors ........................3 12 . D.S. McDougall List of Participants ........................................... 129 ftEXT PAGE(S) left BLAHK SUMMARY 1. INTRODUCTION Potential applications for small commercial reactors could be envisaged in the following areas: Supply of electrical power in remote locations (e.g. Arctic, Great Sahara Desert, Pacific Islands, etc.) for high-value special-purpose applications such as microwave communications and radar navigational aids. Suppl electrif yo c powe head desalinater ran to d wate remotn ri e areas. Utilization of heat in industrial or housing complexes near large population centres. Prolonged dee applicationa pse s wher neee oxyger eth dfo power nfo r generatioe b o t s nha minimized. The initial demonstratio smala f no l commercial reactor would likely involv developmenea t project located near a community capable of providing the required technical nuclear infrastructure, such as a national nuclear research centre. In this case, the power produced could be used to suppor siteneede e th tth .f so The presentations by the participants concentrated on design aspects and user requirements for reactor systems that have less dependence on human intervention. The main mechanism is relianc passivn eo e safety features suc decas ha y heat remova naturay lb l circulation, utilizatiof no stored potential energ d negativan y e temperature coefficient f reactivitieso s . Some papers considered various design option enablo t s e simplified managemen e extenth o t t whern a e autonomous mode of operation is possible for limited periods. Other contributions mainly presented existing designs in the small reactor range. One paper covered public acceptance, which may be a more stringent requirement in a small community and should be dealt with properly (Appendix II). In addition to the papers presented, one working session was devoted to discussion on general issues concerning measure reduco st operationae eth l costs. Small reactors with reduced power ratings can offer potentially significant cost reduction through design simplification and/or reduction of local infrastructure requirements. For small reactors havin glona g grace perio humar dfo n intervention woult i , possible db minimizo et e eth number of highly skilled staff on-site by assigning some of the responsibilities to staff at a remote location. The staff at the central site would also continuously monitor the status of several reactors simultaneously. Us f multipleeo , identical reactor units would hav advantagn ea achievinn ei ghiga h capacity utilization together with adequate flexibilit d redundancyan y t woulI . d also enable serial production, high-quality shop prefabrication, modularization and efficient application of remote monitoring. 2 DEFINITIO TERMINOLOGF NO Y When discussin generae gth l considerationf smalo e l us reactore th identifyind r sfo san g relevant issue their sfo r successful deployment importans i t i , havo t commoea n understandinf go some of the key terms used. For the purpose of this report, the following definitions are adopted: Small commercial reactor A small commercia purpose l th reacto r thif fo e o , sris report, define nucleaa s da r reactor with power levels up to 400 MW(th) (i.e. up to ~100 MWe). This class includes a very small reactor category (about 10 MW(th)) for which siting conditions may be relaxed as a result of low risk levels and long grace periods during postulated accident events. Minimized staffing Minimized staffing reductioe referth o t s f overalno l manpowe sharine th y f skillerb g o d personnel among similar facilities achieves i t I . optimiziny db divisioe gth responsibilitief no d san functions between local staff, central support and the plant itself. Remote monitoring Remote monitoring is the provision of continuous surveillance of the condition of one or more plants from an off-site location that allows an appropriate response within the grace period permitte designe th y db . 3 GENERAL CONSIDERATIONS 3.1. Design Nuclear reactors must compete with other energy sources except in a few special cases for whic e performancth h e characteristic f nucleao s r systems canno e matcheb t y alternatb d e technologies (e.g. certain space power application submarind san e propulsion). No cosl tal t components scale with power thereford an , specifie eth c energy cos smaller tfo r reactor oftes i n high. Consequently, small reactors shouldesignee b t dno d merel scales ya d down versions of larger units, but should take advantage of design simplification that can be achieved with smaller sizes. Realistically, small reactors can more readily incorporate cost saving design feature passivd san e systems. The alsn yoca benefit from associate redundancw dlo y requirements. Moreover smale th , l componen facilitd an t y siz f smaleo l reactorcosw lo t f o s e allowus e sth construction technologies (e.g. standard components, modular designs, shop construction, etc.). High quality heat (i.e. hea higt a t h temperature requires )i manr dfo y applications sucs ha generatio electricitf no y wit hhiga h energy conversion efficiency neae th r n termI . , such systems are likely to use water as the coolant. Accordingly, these systems would benefit directly