RA-S_Edtn_2008.pdf

Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant ApplicationsAN AMERICAN NATIO NAL STANDARDASME/ANS RA-S2008(Revision of ASME RA-S2002)Copyright 2008 by the American Society of Mechanical Engineers.No reproduction may be made of this material without written consent of ASME.cCopyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.ASME/ANS RA-S2008(Revision of ASME RA-S2002)Standard forLevel 1/Large EarlyRelease FrequencyProbabilistic RiskAssessment forNuclear Power PlantApplicationsAN AMERICAN NATIONAL STANDARDCopyright 2008 by the American Society of Mechanical Engineers.No reproduction may be made of this material without written consent of ASME.cCopyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.The 2008 edition of this Standard is being issued with an automatic addenda subscription service.The use of addenda allows revisions made in response to public review comments or committeeactions to be published as necessary.The next edition of this Standard is scheduled for publicationin 2010.ASME issues written replies to inquiries concerning interpretations of technical aspects of thisStandard.Interpretations are published on the ASME Web site under the Committee Pages athttp:/cstools.asme.org.Interpretations are also included with each edition and addenda.ASME is the registered trademark of The American Society of Mechanical Engineers.This code or standard was developed under procedures accredited as meeting the criteria for American NationalStandards.The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate.The proposed code or standard was madeavailable forpublic review andcomment thatprovides an opportunityfor additional publicinput from industry,academia,regulatory agencies,and the public-at-large.ASME does not“approve,”“rate,”or“endorse”any item,construction,proprietary device,or activity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned in this document,and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent,nor assumes any such liability.Users of a code or standard are expresslyadvised that determination of the validity of any such patent rights,and the risk of infringement of such rights,isentirely their own responsibility.Participation by federal agency representative(s)or person(s)affiliated with industry is not to be interpreted asgovernment or industry endorsement of this code or standard.ASME accepts responsibility for only those interpretations of this document issued in accordance with the establishedASME procedures and policies,which precludes the issuance of interpretations by individuals.No part of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue,New York,NY 10016-5990Copyright 2008 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.Copyright 2008 by the American Society of Mechanical Engineers.No reproduction may be made of this material without written consent of ASME.cCopyrighted material licensed to Stanford University by Thomson Scientific(),downloaded on Oct-05-2010 by Stanford University User.No further reproduction or distribution is permitted.Uncontrolled when printed.CONTENTSForeword.ivPreparation of Technical Inquires to the Committee on Nuclear Risk Management.vCommittee Roster.viPreface.viiiPART 1LEVEL 1 AND LERF PROBABILISTIC RISK ASSESSMENT GENERALREQUIREMENTS.1Section 1-1Introduction.1Section 1-2Acronyms and Definitions.7Section 1-3Risk Assessment Application Process.20Section 1-4Risk Assessment Technical Requirements.26Section 1-5PRA Configuration Control.28Section 1-6Peer Review.29Section 1-7References.31Section 1-8For Further Reading.32Nonmandatory Appendix1-APRA Maintenance,PRA Upgrade,and the Advisability of Peer Review.33PART 2INTERNAL EVENTS AT POWER PROBABILISTIC RISK ASSESSMENTREQUIREMENTS.39Section 2-1Risk Assessment Technical Requirements for Internal Events at Power.39Section 2-2Peer Review for Internal Events at Power.119Section 2-3References.121PART 3FIRES AT POWER PROBABILISTIC RISK ASSESSMENT REQUIREMENTS.122Section 3-1Risk Assessment Technical Requirements for Fire Events at Power.122Section 3-2Peer Review for Fire PRA at Power.186Section 3-3References.189Nonmandatory Appendix3-AFPRA Methodology.190PART 4EXTERNAL EVENTS AT POWER PROBABLISTIC RISK A