ANS 53.1-2011 Nuclear safety design process for modular helium-cooled reactor plants.pdf

1、ANSI/ANS-53.1-2011nuclear safety design process formodular helium-cooled reactor plantsANSI/ANS-53.1-2011ANSI/ANS-53.1-2011American National StandardNuclear Safety Design Processfor Modular Helium-Cooled Reactor PlantsSecretariatAmerican Nuclear SocietyPrepared by theAmerican Nuclear SocietyStandard

2、s CommitteeWorking Group ANS-53.1Published by theAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USAApproved December 21, 2011by theAmerican National Standards Institute, Inc.AmericanNationalStandardDesignation of this document as an American National Standard attes

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12、estsThe American Nuclear Society ANS! Standards Committee will provide re-sponses to inquiries about requirements, recommendations, and0or permissivestatementsi.e., “shall,” “should,” and “may,” respectively!in American NationalStandards that are developed and approved by ANS. Responses to inquiries

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14、operation,facility, or other unique situation, and therefore is not intended for genericapplication.Responses to inquiries on standards are published in ANSs magazine, NuclearNews, and are available publicly on the ANS Web site or by contacting the ANSstandards administrator.InquiryFormatInquiry req

15、uests must include the following:1! the name, company name if applicable, mailing address, and telephonenumber of the inquirer;2! reference to the applicable standard edition, section, paragraph, figure,and0or table;3! the purposes of the inquiry;4! the inquiry stated in a clear concise manner;5! a

16、proposed reply, if the inquirer is in a position to offer one.Inquiries should be addressed toAmerican Nuclear SocietyATTN: Standards Administrator555 N. Kensington AvenueLa Grange Park, IL 60526or standardsans.orgForewordThis Foreword is not a part of American National Standard “Nuclear Safety Desi

17、gnProcess for Modular Helium-Cooled Reactor Plants,” ANSI0ANS-53.1-2011.!The purpose of this standard is to provide nuclear safety criteria applicable tothe design of modular helium-cooled reactor MHR! nuclear power plants here-inafter referred to as “plants”!. To achieve this purpose, this standard

18、 provides aprocess that can be used todevelop MHR top-level nuclear regulatory safety criteria;identify safety functions, top-level design criteria, licensing-basis events, design-basis accidents, and methods for performing safety analyses;determine safety classification of systems, structures, and

19、componentsSSCs!;identify safety-related SSC special treatment requirements and defense-in-depth DID! provisions;demonstrate the adequacy of DID by applying a risk-informed approach.This standard does not address plant security design requirements or criteria.MHR security design requirements, includi

20、ng design-basis threats, are designelements that may be brought into the plant design process to address licensingrequirements of the national nuclear regulator. In general, both deterministicand risk-based approaches may be considered in the plant security design pro-cess. It is anticipated that MH

21、R passive safety features and inherent safetycharacteristics together with the use of the risk-informed nuclear safety processherein will effectively support plant security design.This risk-informed process standard represents a new design approach for pro-fessional communities familiar with traditi

22、onal, deterministic light water reactorLWR! design processes. These include plant architect0engineers, nuclear licens-ing, and risk assessment professionals. This process presents an opportunity toextend traditional use of probabilistic risk assessment as applied to LWRs toMHRs and to incorporate ri

23、sk insights early in the design process. Two examplesarea!modeling long-duration nonequilibrium plant conditions andb!extensivequantification of event frequency and consequence, including uncertainty. Nu-clear professional communities should develop other complementary risk-informed, performance-bas

24、ed consensus processes that continue to address thechallenges presented with this standard.In addition to designers, regulators, and the risk community, this standardprovides a tool for plant operators who use design processes to maintain licensedplant designs. Some uses of this standard, such as SS

25、C classification, applybeyond initial plant design, procurement, and construction into operations. Useof this standard for SSC classification also allows plant owner0operators tospecify special treatments over the life of the plant for procurement, application,testing, and maintenance commensurate w

26、ith risk. This standard documents anestablished process that nuclear design organizations can use to develop nuclearsafety designs. It is anticipated that sponsors and communities of MHR-baseddesigns will develop further specific designs with dependent standards thatintegrate these risk-informed cha

27、racteristics. In any event, the fundamentalobjective of this standard is to provide clear design process guidance subordinateto the MHRs fundamental design technology. Because the traditional LWR de-sign community is unfamiliar with MHR technology, it is expected that thisstandard will present the f

28、irst non-LWR design process challenge.Consider the question of secondary containment in LWRs. For high-temperaturegas-cooled reactors HTGRs!, fundamentally different approaches to retention ofradionuclides lead to differences in the design of the reactor building.iTo specify “containment” directly,

29、as commonly used and interpreted for LWRs,would supersede the design development process of this standard. Therefore,that is not done. The design process provided in this standard is adequate aloneto assure that the containment of radionuclide safety functions is accomplished.For that reason, this s

30、tandard does not specify discrete design applications thatthose familiar with other reactor types, like LWRs, might expect. Rather, onlythe fundamental attributes that distinguish an MHR are provided. Those are theminimum set of design characteristics, agreed upon by this working group,which must be

31、 met for the use of this standard.This standard could reference documents or other standards that have beensuperseded or withdrawn when the standard is applied. In that case, referencesin the sections! include statements that provide guidance on their use. Theformat of the standard provides a table

32、at the end of each body of text thatsummarizes and provides succinct actionable content required. The “Summary ofRequirements” tables at the end of each body of text provide that body of textsexplicit requirements. Users should evaluate the requirements with the tables atthe end of each body of text

33、. In the event of a compliance question with thestandards requirements, evaluation should include the explicit body of text inthe standard. The tables should be used to evaluate compliance, in the event ofa question of compliance with the standards requirements.This standard was initiated in 1971 an

34、d released as N213, January 1974 Draft,“Nuclear Safety Criteria for the Design of Stationary Gas Cooled Reactor Plants,”for comment. Waning interest in gas reactors left that early deterministic stan-dard incomplete. Two LWR counterparts, ANSI N18.2-1973, “Nuclear SafetyCriteria for the Design of St

35、ationary Pressurized Water Reactor Plants” redes-ignated ANS-51.1!, and ANSI0ANS-52.1-1978, “Nuclear Safety Criteria for theDesign of Stationary Boiling Water Reactor Plants,” were completed and ap-proved. Revisions of both these standards were approved in 1983 adding a formof risk-based classificat

36、ion; however, all these documents remained essentiallydeterministic compilations of the state-of-the-art design from that era.The American Nuclear Society Gas-Cooled Reactor Design and Operation Sub-committee, ANS-28, was inaugurated in November 2003 and tasked with devel-oping ANS-53.1. The working

37、 group was quickly formed and began developmenton this standard in 2004. Use of this standard does not supersede the responsi-bility to review and apply the top-level safety criteria TLSC! of the authoritiesin the country where the user plans to license, build, and operate MHRs!. Theusers of this st

38、andard are responsible to review and apply the TLSC set by theauthorities in whichever country the user plans to license, build, and operateMHRs!. This standard may also be used to support the preparation of an MHRsafety analysis report for the purpose of MHR licensing. When used for MHRlicensing, t

39、he standard does not provide the only basis for establishing theMHR safety and design criteria. The designer also assesses the applicability ofthe existing body of technical licensing requirements and guidance for nuclearplant licensing in the particular country of application. In this regard, thede

40、signer determines the applicability, partial applicability, or nonapplicability ofthese licensing requirements. The designer may also use this standard and othersupporting standards to determine what additional MHR licensing technicalrequirements are required for important technical design and safet

41、y aspects thatare not addressed by the existing body of technical licensing requirements andguidance.In light of the 2011 disaster in Japan at Fukushima Daiichi Units 1 through 4,the ANS-28 Subcommittee stresses that those events have been considered foriithis standard as well as they are known at t

42、his time. Furthermore, while thoseissues are being developed, as a process standard, we do not anticipate that theprocess that this standard identifies will be changed at all. This standard doesnot exclude the use of any additional guidance or requirements to supplementthat information.The ANS-53.1

43、Working Group consisted of the entire ANS-28 Subcommittee ofthe American Nuclear Society. Members of ANS-28 who participated directly inthe development of this standard are as follows:J. K. August* Chair, 20072011; Vice Chair, 20032007!, CORE, Inc.M. A. LaBar Chair, 20032007!, General AtomicsR. L. B

44、ratton Secretary!, Idaho National LaboratoryJ. M. Bolin, General AtomicsS. A. Caspersson, Westinghouse Electric Company, LLCM. T. Coyle, Exelon NuclearJ. C. Cunliffe, Bechtel Systems General Atomics, who provided historical modular high-temperature gas reactor0HTGR licensing interpretations; and Peb

45、ble Bed Mod-ular Reactors Pty!, Ltd., who provided the extensive basis behind its currentlicense application, especially licensing application of DID principles. We arealso indebted to the U.S. Nuclear Regulatory Commission for introducing risk-informed guidance, existing regulatory interpretations,

46、 and extensive unacknowl-edged staff review assistance. Finally, all contributor companies and their employeeswho so generously donated their time include CORE, Inc.; AREVA NP, Inc.;Westinghouse; UT-Battelle0ORNL; Battelle Energy Alliance and Oak Ridge con-tractors to DOE; the Electric Power Researc

47、h Institute; Bechtel; Exelon Nuclear;and General Atomics.The Nuclear Facility Standards Committee NFSC! had the following member-ship at the time of its approval of this standard:C. A. Mazzola Chair!, Shaw Environmental safety functions; top-level design crite-ria TLDC!; licensing-basis events LBEs!

48、;design-basis accidents DBAs!; safety classifi-cation of systems, structures, and componentsSSCs!; safety analyses; defense-in-depthDID!;and adequate assurance of special treatmentrequirements for safety-related SSCs through-out the operating life of the plant. This stan-dard does not provide detail

49、ed guidance fordesign; other existing standards cover that.Plants maintain radioactive releases within pub-lic health and safety requirements by passiveSSCs and0or inherent characteristics by de-sign. They rely on intrinsic physical character-istics and specific design requirements to dothis. While it is beyond the scope of this stan-dard to explain how, the following descriptionof MHR design characteristics provides the ba-sis for this attribute claim. Plants have one ormore standard helium-cooled reactor modules,where each module has the follo