1、ANSI/ANS-53.1-2011nuclear safety design process formodular helium-cooled reactor plantsANSI/ANS-53.1-2011This standard has been reviewed and reaffirmed with the recognition that it may reference other standards and documents that may have been superseded or withdrawn. The requirements of this docume
2、nt will be met byusing the version of the standards and documents referenced herein. It is the responsibility of the user to review each of the references and to determine whether the use of the original references or more recent versions is appropriate for the facility. Variations from the standard
3、s and documents referenced in this standard should be evaluated and documented. This standard does not necessarily reflect recent industry initiatives for risk informed decision-making or a graded approach to quality assurance. Users should consider the use of these industry initiatives in the appli
4、cation of this standard. ANSI/ANS-53.1-2011American National StandardNuclear Safety Design Processfor Modular Helium-Cooled Reactor PlantsSecretariatAmerican Nuclear SocietyPrepared by theAmerican Nuclear SocietyStandards CommitteeWorking Group ANS-53.1Published by theAmerican Nuclear Society555 Nor
5、th Kensington AvenueLa Grange Park, Illinois 60526 USAApproved December 21, 2011by theAmerican National Standards Institute, Inc.AmericanNationalStandardDesignation of this document as an American National Standard attests thatthe principles of openness and due process have been followed in the appr
6、ovalprocedure and that a consensus of those directly and materially affected bythe standard has been achieved.This standard was developed under the procedures of the Standards Commit-tee of the American Nuclear Society; these procedures are accredited by theAmerican National Standards Institute, Inc
7、., as meeting the criteria forAmer-ican National Standards. The consensus committee that approved the stan-dard was balanced to ensure that competent, concerned, and varied interestshave had an opportunity to participate.An American National Standard is intended to aid industry, consumers, gov-ernme
8、ntal agencies, and general interest groups. Its use is entirely voluntary.The existence of an American National Standard, in and of itself, does notpreclude anyone from manufacturing, marketing, purchasing, or using prod-ucts, processes, or procedures not conforming to the standard.By publication of
9、 this standard, the American Nuclear Society does not insureanyone utilizing the standard against liability allegedly arising from or afterits use. The content of this standard reflects acceptable practice at the time ofits approval and publication. Changes, if any, occurring through developmentsin
10、the state of the art, may be considered at the time that the standard issubjected to periodic review. It may be reaffirmed, revised, or withdrawn atany time in accordance with established procedures. Users of this standardare cautioned to determine the validity of copies in their possession and toes
11、tablish that they are of the latest issue.The American Nuclear Society accepts no responsibility for interpretations ofthis standard made by any individual or by any ad hoc group of individuals.Responses to inquiries about requirements, recommendations, and0or permis-sive statements i.e., “shall,” “
12、should,” and “may,” respectively! should be sentto the Standards Department at Society Headquarters. Action will be taken toprovide appropriate response in accordance with established procedures thatensure consensus.Comments on this standard are encouraged and should be sent to SocietyHeadquarters.P
13、ublished byAmerican Nuclear Society555 North Kensington AvenueLa Grange Park, Illinois 60526 USACopyright 2011 by American Nuclear Society. All rights reserved.Any part of this standard may be quoted. Credit lines should read “Extracted fromAmerican National Standard ANSI0ANS-53.1-2011 with permissi
14、on of the publisher,the American Nuclear Society.” Reproduction prohibited under copyright conventionunless written permission is granted by the American Nuclear Society.Printed in the United States of AmericaInquiryRequestsThe American Nuclear Society ANS! Standards Committee will provide re-sponse
15、s 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 willbe provided according to the Policy Manual for the ANS Standards Committee.
16、Nonrelevant inquiries or those concerning unrelated subjects will be returnedwith appropriate explanation. ANS does not develop case interpretations ofrequirements in a standard that are applicable to a specific design, operation,facility, or other unique situation, and therefore is not intended for
17、 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 requests must include the following:1! the name, company name if applicable, mailin
18、g 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 proposed reply, if the inquirer is in a position to offer one.Inquiries should b
19、e 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 DesignProcess for Modular Helium-Cooled Reactor Plants,” ANSI0ANS-53.1-2011.!The pur
20、pose 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 provides aprocess that can be used todevelop MHR top-level nuclear regulatory s
21、afety 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 componentsSSCs!;identify safety-related SSC special treatment requirements and d
22、efense-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, including design-basis threats, are designelements that may be brought into the plant d
23、esign 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 MHR passive safety features and inherent safetycharacteristics together with the u
24、se 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 traditional, deterministic light water reactorLWR! design processes. These include plan
25、t 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 risk insights early in the design process. Two examplesarea!modeling long-duration
26、 nonequilibrium plant conditions andb!extensivequantification of event frequency and consequence, including uncertainty. Nu-clear professional communities should develop other complementary risk-informed, performance-based consensus processes that continue to address thechallenges presented with thi
27、s 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 SSC classification, applybeyond initial plant design, procurement, and constructio
28、n 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 with risk. This standard documents anestablished process that nuclear design orga
29、nizations 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 characteristics. In any event, the fundamentalobjective of this standard is to prov
30、ide 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 first non-LWR design process challenge.Consider the question of secondary contain
31、ment 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, as commonly used and interpreted for LWRs,would supersede the design development
32、 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 standard does not specify discrete design applications thatthose familiar with ot
33、her 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 met for the use of this standard.This standard could reference documents or oth
34、er 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 at the end of each body of text thatsummarizes and provides succinct actionable
35、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. In the event of a compliance question with thestandards requirements, evaluati
36、on 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 and released as N213, January 1974 Draft,“Nuclear Safety Criteria for the Design o
37、f 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 Stationary Pressurized Water Reactor Plants” redes-ignated ANS-51.1!, and ANSI0ANS
38、-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 classification; however, all these documents remained essentiallydeterministic compilations
39、 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 group was quickly formed and began developmenton this standard in 2004. Use of
40、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 standard are responsible to review and apply the TLSC set by theauthorities in whi
41、chever 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, the standard does not provide the only basis for establishing theMHR safety and d
42、esign 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, thedesigner determines the applicability, partial applicability, or nonapplicability
43、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 safety aspects thatare not addressed by the existing body of technical licensing requ
44、irements 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 this time. Furthermore, while thoseissues are being developed, as a process stand
45、ard, 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 Working Group consisted of the entire ANS-28 Subcommittee ofthe American Nuclear
46、 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. Bratton Secretary!, Idaho National LaboratoryJ. M. Bolin, General AtomicsS. A. Ca
47、spersson, 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 Pebble Bed Mod-ular Reactors Pty!, Ltd., who provided the extensive basis behind it
48、s 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, and extensive unacknowl-edged staff review assistance. Finally, all contributor
49、 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 Research 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!;design-basis accidents DBAs!; s
