NRC Generic Letter 1983-11
OMB Control No. 3150-0011 June 24, 1999NRC GENERIC LETTER 83-11, SUPPLEMENT 1: LICENSEE QUALIFICATION FORPERFORMING SAFETY ANALYSES
Addressees
All holders of operating licenses for nuclear power plants, including those who havepermanently ceased operations and have certified that fuel has been permanently removedfrom the reactor vessel.
Purpose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this supplement to Generic Letter(GL) 83-11 to notify licensees and applicants of modifications to the Office of Nuclear ReactorRegulation (NRR) practice regarding licensee qualification for performing their own safetyanalyses. This includes the analytical areas of reload physics design, core thermal-hydraulicanalysis, fuel mechanical analysis, transient analysis (non-LOCA), dose analysis, setpointanalysis, containment response analysis, criticality analysis, statistical analysis, and CoreOperating Limit Report (COLR) parameter generation. It is expected that recipients will reviewthe information for applicability to their facilities. However, suggestions contained in thissupplement to the generic letter are not NRC requirements; therefore, no specific action orwritten response is required.BackgroundOver the past decade, substantially more licensees have been electing to perform their ownsafety analyses to support such tasks as reload applications and technical specificationamendments, rather than to contract the work out to their nuclear steam supply system (NSSS)vendor, fuel vendor, or some other organization. The NRC encourages utilities to perform theirown safety analyses, since doing this significantly improves licensee understanding of plantbehavior. GL 83-11 presented guidance on the information that NRC needs in order to qualifylicensees to perform their own safety analyses using approved computer codes.
Description of Circumstances
NRC's experience with safety analyses using large, complex computer codes has shown thaterrors or discrepancies discovered in safety analyses are more likely to be traced to the userrather than to the code itself. This realization has led the NRC to place additional emphasis on2101 t ARLD0L1 05Scoo obv ftGtq/Pd&A t ? 0tX02 V
-lGL 83-11, Supp. 1June 24, 1999 assuring the capabilities of the code users as well as on assuring the codes themselves. In thepast, NRC obtained this assurance by reviewing the code verification information submitted bythe licensee. The reviews focused primarily on the licensee's quality assurance practices andthe technical competence of the licensee with respect to their ability to set up an input deck,execute a code, and properly interpret the results. The information which was reviewedgenerally Included comparisons (performed by the user of the code results) with experimentaldata, plant operational data, or other benchmarked analyses, as well as compliance with anyrestrictions or limitations stated in the generic NRC Safety Evaluation Report (SER) thatapproved the code.Since GL 83-11 was issued, many licensees have submitted information in the form of topicalreports demonstrating their ability to perform their own safety analyses, such as reloadanalyses using NRC-approved methods and codes. Preparation and review of a qualificationtopical report is resource intensive on the part of the staff and the licensee, and because thereview is usually assigned a low priority, it is difficult to schedule the review for timelycompletion.DiscussionTo help shorten the lengthy review and approval process, the NRC has adopted a generic setof guidelines which, if met, would eliminate the need to submit detailed topical reports for NRCreview before a licensee could use approved codes and methods. These guidelines arepresented in the Attachment to this Generic Letter. Using this approach, which is consistentwith the regulatory basis provided by Criteria II and IlIl of Appendix B to Part 50 of Title 10 of theCode of Federal Regulations (10 CFR Part 50), the licensee would institute a program (such astraining, procedures, and benchmarking) that follows the guidelines, and would notify NRC byletter that it has done this and that the documentation is available for NRC audit.SummaryThe revised guidance on licensee qualification for using safety analysis codes Is intended forlicensees who wish to perform their own licensing analyses using methods that have beenreviewed and approved by the NRC, or that have otherwise been accepted as part of a plant'slicensing basis.
Backfit Discussion
This supplement does not involve a backfit as defined in 10 CFR 50.109(a)(1), since i doesnothing more than offer guidance as to an acceptable means by which a licensee may verify tothe NRC its qualifications to use approved codes and methods for performing safety analyses.Therefore, the staff has not prepared a backet analysi lK>'ISGL 83-11, Supp. IJune 24, 1999
Federal Register Notification
A notice of opportunity for public comment was published in the Federal Register (60 FR54712) on October 25, 1995. Comments were received from 13 licensees, 3 fuel vendors, and3 industry interest groups. Copies of the comment letters received and the staff's evaluation ofthese comments are available in the NRC Public Document Room. Because of concurrentIssues that arose at the Maine Yankee nuclear power reactor facility regarding the improperapplication of approved methods, the NRC decided to withdraw the Issuance of the supplementto GL 83-11 pending a complete review of these issues. Subsequent review of the lessonslearned from Maine Yankee indicated that the Issues involved were adequately addressed Inthe GL 83-11 supplement as published for public comment. Therefore, the NRC decided toproceed with the issuance of the supplement.In addition to the proposed supplement to GL 83-11, the staff also requested comments onmodified procedures for reducing the resource effort for acceptance of new or revised licenseeor vendor analysis methods. These comments will be addressed in a future staff action.
Paperwork Reduction Act Statement
This generic letter contains a voluntary collection that is subject to the Paperwork Reduction Actof 1995 (22 U.S.C. 3501 et seq.). This information collection was approved by the Office ofManagement and Budget, approval number 3150-0011, through September 30, 2000.The public reporting burden for this collection of information is estimated to average 100 hour0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />sper response, including the time for reviewing instructions, searching existing data sources,gathering and maintaining the data needed, and completing and reviewing the collection ofinformation. The NRC is seeking public comment on the potential impact of the collection ofinformation contained in the generic letter and on the following issues:(1) Is the proposed collection of information necessary for the proper performance of thefunctions of the NRC, including consideration of whether the information will havepractical utility?(2) Is the estimate of burden accurate?(3) Is there a way to enhance the quality, utility, and clarity of the information to becollected?(4) How can the burden of the collection of information be minimized, Includingconsideration of the use of automated collection techniques?
K-)GL 83-11, Supp. 1June 24, 1999 Send comments on any aspect of this collection of information, including suggestions forreducing this burden, to the Information and Records Management Branch, T-6 F33, U.S.Nuclear Regulatory Commission, Washington, D.C. 20555-0001, and to the Desk Officer,Office of Information and Regulatory Affairs, NEOB-10202, (3150-0011), Office of Managementand Budget, Washington, D.C. 20503.The NRC may not conduct or sponsor, and a person is not required to respond to, a collectionof information unless it displays a currently valid OMB control number.This generic letter requires no specific action or written response. If you have any questionsabout this matter, please contact the technical contact or the lead project manager listed below.DavidB Matthews, Director(\Division of Regulatory Improve ent ProgramsOffice of Nuclear Reactor RegulationTechnical contact: Laurence I. Kopp, NRR(301) 415-2879E-mail: likffnrc.aovLead project manager: Steven Bloom, NRR(301) 415-1313E-mail: sdbla(nrc.Qov
Attachments:
1. Guidelines for Qualifying Licensees toUse Generically Approved Analysis Methods2. List of Recently Issued NRC Genernc Letters Attachment 1GL 83- 1, Supp. IJune 24, 1999Page Iof 2GUIDELINES FOR QUALIFYING LICENSEES TO USEGENERICALLY APPROVED ANALYSIS METHODS1.0 INTRODUCTIONThis attachment presents a simplified approach for qualifying licensees to use NRC-approvedanalysis methods. Typically, these methods are developed by fuel vendors, utilities, nationallaboratories, or organizations such as the Electric Power Research Institute, Incorporated,(EPRI). To use these approved methods, the licensee would institute a program (e.g., training,procedures) that follows the guidelines below and notify the NRC that it has done so.The words "code" and "method" are used interchangeably within this document, i.e., acomputer program. In many cases, however, an approved method may refer not only to a setof codes, an algorithm within a code, a means of analysis, a measurement technique, astatistical technique, etc., but also to selected input parameters which were specified In themethodology to ensure conservative results. In some cases, due to limitations or lack ofappropriate data in the model, the code or method may be limited to certain applications. Inthese cases, the NRC safety evaluation report (SER) specifies the applicability of themethodology.2.0 GUIDELINESA commitment on the part of a licensee to implement the guidelines delineated in this documentis sufficient information for the NRC to accept the licensee's qualification to use an approvedcode or method to perform safety-related evaluations such as reload physics design, corethermal-hydraulic analysis, fuel mechanical analysis, non-LOCA transient analysis, doseanalysis, setpoint analysis, containment response analysis, criticality analysis, statisticalanalysis, and Core Operating Limit Report (COLR) parameter generation. To document Itsqualification in this manner, the licensee should send the NRC a notification of its havingfollowed the guidelines at least 3 months before the date of its intended first licensingapplication.2.1 EligibilityThe only codes and methods that are addressed by this process are those that NRC hasreviewed and approved generically, or those that have been otherwise accepted as part of aplant's licensing basis. The use of a new methodology or a change to an existing methodologyis not applicable to this process.2.2 A1Dlication ProceduresIn-house application procedures, which ensure that the use of approved methods Is consistentwith the code qualification and, in most instances, with the approved application of themethodology, should be established and implemented. Because of the bounding nature of Attachment IGL 83-11, Supp. IJune 24,1999 restrictions, including any defined in the licensing topical report, correspondence with the NRC, and the SER.The applicability of a particular method to either a specific fuel design or to a core which contains a mixture offuel types is important. For example, the use of one vendors hot channel analysis code with a differentvendors transient codes may not necessarily yield conservative results and, In fact, may not be consistent withthe NRC-approved reload analysis package. Therefore, In-house application procedures should have theproper controls to preclude such a misapplication but should also include the flexibility to allow comparisontests between the different methodologies to show that a conservative assessment can be made.2.3 Training and Qualification of Licensee PersonnelA training program should~be established and Implemented to ensure that each qualified user of an approvedmethodology has a good working knowledge of the codes and methods, and will be able to set up the input, tounderstand and interpret the output results, to understand the applications and limitations of the code, and toperform analyses In compliance with the application procedure. Training should be provided by either thedeveloper of the code or method, or someone who has been previously qualified in the use of the code ormethod.2.4 Comparison CalculationsUcensees should verify their ability to use the methods by comparing their calculated results to an appropriateset of benchmark data, such as physics startup tests, measured flux detector data during an operating cycle,higher order codes, published numerical benchmarks, analyses of record, etc. These comparisons should bedocumented in a report which is part of the licensee's quality assurance (QA) records. Significant,unexpected, or unusual deviations in the calculations of safety-related parameters should be justified in thereport. All comparisons with startup test data should agree within the acceptance criteria defined in the plantstartup test plan.2.5 Quality Assurance and Change ControlAll safety-related licensing calculations performed by a licensee using NRC-approved codes and methodsshould be conducted under the control of a QA program which complies with the requirements of Appendix Bto Part 50 of Title 10 of the Code of Federal Regulations (10 CFR Part 50). The licensee's QA program shouldalso include the following:(1) a provision for evaluating vendor (or other code developer) updates and implementing thoseupdates, If applicable, in codes, methods, and procedures; and(2) a provision for informing vendors (or code developers) of any problems or errors discoveredwhile using their codes, methods, or procedure J-Attachment 2GL 83-11, Supp .1June 24,1999Page 1 of ILIST OF RECENTLY ISSUED GENERIC LETTERSGENERICLElTER99-02SUBJECTLaboratory Testing of Nuclear-Grade Activated CharcoalDATE OFISSUANCE613/99ISSUED TOAll holders of operatingLicenses for nuclear powerreactors, except those whohave permanently ceasedoperations and have certifiedthat fuel has beenpermanently removed fromthe reactor vessel.99-01Recent Nuclear Material Safetyand Safeguards Decision onBundling Exempt Quantities513/99All materials licensees.98-01, Supp. IYear 2000 Readiness of ComputerSystems at Nuclear Power Plants1111199All holders of operating Iilicenses for nuclear powerPlants, except those whohave permanently ceasedoperations and have certifiedthat fuel has beenpermanently removed fromthe reactor vessel.98-0598-04Boiling Water Reactor Licensees 11/10/98Use of the BWRVIP-05 ReportTo Request Relief From AugmentedExamination Requirements on ReactorPressure Vessel Circumferential ShellWeldsAll holders of operatinglicenses (or constructionpermits) for BWRs, exceptthose who have permanentlyceased operations and havecertified that fuel has beenpermanently removed fromthe reactor vessel.All holders of operatinglicenses for nuclear powerreactors, except those whohave permanently ceasedoperations and have certifiedthat fuel has beenpermanently removed fromthe reactor vessel.Potential for Degradation of the 07/14/98Emergency Core Cooling SystemAnd the Containment Spray SystemAfter a Loss-of-Coolant AccidentBecause of Construction andProtective Coating Deficienciesand Foreign Material in ContainmentOP = Operating LicenseCP = Construction PermitNPR = Nuclear Power Reactors
\> HiGL 83-11, Supp. 1June 24, 1999 Send comments on any aspect of this collection of information, including suggestions forreducing this burden, to the Information and Records Management Branch, T-6 F33, U.S.Nuclear Regulatory Commission, Washington, D.C. 20555-0001, and to the Desk Officer,Office of Information and Regulatory Affairs, NEOB-10202, (3150-0011), Office of Managementand Budget, Washington, D.C. 20503.The NRC may not conduct or sponsor, and a person is not required to respond to, a collectionof information unless it displays a currently valid OMB control number.This generic letter requires no specific action or written response. If you have any questionsabout this matter, please contact the technical contact or the lead project manager listed below.Original /s/'d by S.F. Newberryfor David B. Matthews, DirectorDivision of Regulatory Improvement ProgramsOffice of Nuclear Reactor RegulationTechnical contact: Laurence I. Kopp, NRR(301) 415-2879E-mail: lik(lnrc.aovLead project manager: Steven Bloom, NRR(301) 415-1313E-mail: sdb10-nrc.qov
Attachments:
1. Guidelines for Qualifying Licensees toUse Generically Approved Analysis Methods2. List of Recently Issued NRC Generic LettersC *4Vr'#SWDOCUMENT NAME: S:\DRPMSEC\83-11S1.glTo receive a copy of this document, indicate in the box C=Copy wfo attachment/enclosure E=Copy with attachmenVenclosure N = No copyOFFICE PECB I I le SRXB l C:PE D:DRIP jINAME JShapakerl f4 IKop P 4ars DMatt4stDATE 61 V PP XI/0499_7 I OFFICIAL RECORD COPY