NRC Generic Letter 1996-06

NRC Generic Letter 1996-006, Supplement 1: Assurance of Equipment Operability and Containment Integrity During Design Basis Accident Conditions

ML031110029
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Washington Public Power Supply System, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant, Clinch River, Crane
Issue date:	11/13/1997
From:	Roe J W NRC/NRR/DLPM
To:
References
GL-96-006, Suppl 1, NUDOCS 9711050091
Download: ML031110029 (8)

UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555-0001November 13, 1997NRC GENERIC LETTER 96-06, SUPPLEMENT 1: ASSURANCE OF EQUIPMENTOPERABILITY AND CONTAINMENTINTEGRITY DURING DESIGN-BASISACCIDENT CONDITIONS

Addressees

All holders of operating licenses for nuclear power reactors except 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) 96-06, "Assurance of Equipment Operability and Containment Integrity During Design-Basis Accident Conditions," to inform addressees about ongoing efforts and newdevelopments associated with GL 96-06 and to provide additional guidance for completingcorrective actions.

Addressees

may find this information useful in planning and schedulingfuture actions associated with GL 96-06. This generic letter supplement contains no newNRC requirements. Furthermore, no specific action or written response is required.BackgroundGL 96-06 was issued on September 30, 1996, to address the following issues of concem:1. Cooling water systems serving the containment air coolers may be exposed to thehydrodynamic effects of waterhammer during either a loss-of-coolant accident (LOCA)or a main steam line break (MSLB). These cooling water systems were not designedto withstand the hydrodynamic effects of waterhammer and actions may be needed tosatisfy system design and operability requirements.2. Cooling water systems serving the containment air coolers may experience two-phaseflow conditions during postulated LOCA and MSLB scenarios. The heat removalassumptions for design-basis accident scenarios are based on single-phase flowconditions and actions may be needed to satisfy system design and operabilityrequirements.3. Thermally induced overpressurization of isolated water-filled piping sections incontainment could jeopardize the ability of accident-mitigating systems to perform theirsafety functions and could lead to a breach of containment integrity through bypassleakage. Actions may be needed to satisfy system operability requirements.PPgQ FN^C*L C'SOZ'OOO2) 1 AdIjI____________ Id 11.nf (J afI~l ill (1111 I7IllI~Il~ll~iI !L Ill GL 96-06, Supplement 1November 13, 1997 GL 96-06 states-"If systems are found to be susceptible to the conditions discussed in thisgeneric letter, addressees are expected to assess the operability of affectedsystems and take corrective action as appropriate in accordance with therequirements stated in 10 CFR Part 50 Appendix B and as required by theplant Technical Specifications."GL 96-06 refers to GL 91-18, "Information to Licensees Regarding Two NRC InspectionManual Sections on Resolution of Degraded and Nonconforming Conditions and onOperability," for guidance on the resolution of issues identified in GL 96-06. (Note:GL 91-18, Revision 1 was issued on October 8, 1997, to inform licensees of the issuance ofa revised section of the NRC Inspection Manual, Part 9900, 'Technical Guidance," on theresolution of degraded and nonconforming conditions. The GL 96-06 reference to GL 91-18remains valid since it refers only to the "Technical Guidance" on operability, which was notchanged by the issuance of GL 91-18, Revision 1.) Criterion XVI, "Corrective Actions," ofAppendix B to 10 CFR Part 50 states, in part, "Measures shall be established to assurethat.. .nonconformances are promptly identified and corrected." In this regard, GL 91-18states that the timeliness of corrective actions should be commensurate with the safetysignificance of the issue, and that the corrective action requirements of Appendix B may besatisfied by making changes in the design of the plant in lieu of restoring the affectedequipment to its original design. In one example, GL 91-18 specifically discusses the use ofthe American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASMECode),Section III, Appendix F, criteria for interim operability determinations for degraded andnonconforming piping and pipe supports. It states that the use of Appendix F criteria is validuntil the next refueling outage when the supports are to be restored to the final safetyanalysis report criteria.

Addressees

have responded to the generic letter and have established schedules forresolving the GL 96-06 issues. The NRC staff is currently reviewing the information that hasbeen submitted.DiscussionImplementing corrective actions to resolve the GL 96-06 issues can have a significant impacton outage schedules and resources, and some addressees have indicated that it would beprudent to take more time to better understand the specific concerns that have beenidentified in order to optimize whatever modifications are needed and to assure that they donot ultimately result in a detriment to safety. Current issues and ongoing efforts that couldinfluence an addressee's decision in planning corrective actions include: (1) risk implicationsof installing relief valves to deal with the thermal overpressurization issue; (2) feasibility ofusing the acceptance criteria contained in Appendix F to Section III of the American Societyof Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code) for the permanentresolution of the GL 96-06 issues; (3) ongoing tests by the Electric Power Research Instituteto support a generic resolution of the overpressurization of piping issue; and (4) questions GL 96-06, Supplement 1November 13, 1997 regarding the staffs closure of Generic Safety Issue 150, "Overpressurization of ContainmentPenetrations." Risk insights and industry initiatives that are being considered or that may beproposed could also influence the course of action that addressees take to resolve theGL 96-06 issues.

Addressees

are responsible for assessing equipment operability, determining actions, andestablishing schedules that are appropriate for resolving the specific conditions that havebeen identified. In determining the appropriate actions and schedules for resolving GL 96-06issues, addressees should consider, for example, the continued validity of existing operabilitydeterminations, compensatory actions required to maintain operability, the safety significanceassociated with the specific nonconformances or degraded conditions that have beenidentified, risk insights, and the time required to complete any generic initiatives and/or plant-specific actions (e.g., engineering evaluations, design change packages, materialprocurement, and equipment modification and installation). Also, analytical solutionsemploying the permanent use of the acceptance criteria contained in the ASME Code,Section III, Appendix F (or other acceptance criteria) may present viable alternatives to plantmodifications and can be used where appropriate, justified, and evaluated in accordance withNRC requirements such as 10 CFR 50.59, as applicable.

Addressees

may find the revisedguidance contained in GL 91-18, Revision 1, dated October 8, 1997, helpful in determiningappropriate actions and schedules. Although adjustments in schedules may be warranted onthe basis of these (and other) considerations, specific actions that have been defined and areclearly needed should not be delayed without suitable justification.It is the staffs current position that addressees can use the ASME Code, Section 1II,Appendix F criteria for interim operability determinations for degraded and nonconformingpiping and pipe supports until permanent actions have been identified and approved by theNRC (as applicable) for resolving the GL 96-06 issues. This guidance supplements theguidance provided by GL 91-18 for resolution of the GL 96-06 issues.In order to further facilitate resolution of the GL 96-06 issues, the NRC will participate in apublic workshop scheduled for December 4, 1997. The workshop proceedings will besummarized by the NRC staff and made publicly available. The need for additional NRCguidance and generic communication will be considered upon completion of the workshop.Reauested Information

Addressees

who choose to revise their commitments for resolving the GL 96-06 issuesshould submit a revised response to the generic letter. Revised responses should includeappropriate discussion of the considerations discussed above, the current resolution statusand actions remaining to be completed, and plans being considered for final resolution of theGL 96-06 issues.

GL 96-06, Supplement 1November 13, 1997

Federal Register Notification

Because this GL supplement is informational, requires no specific action or response, and isthe result of ongoing efforts between NRC staff and addressees to resolve GL 96-06 issues,there is no need for additional opportunities for comment. Accordingly, a notice ofopportunity for public comment was not published in the Federal Register. However,comments on the content of this supplement to GL 96-06 may be sent to the U.S. NuclearRegulatory Commission, ATTN: Document Control Desk, Washington, D.C. 20555-0001.

Paperwork Reduction Act Statement

For those addressees who find it necessary to revise their commitments for resolving theGL 96-06 issues, this generic letter supplement contains information collections that aresubject to the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.). These informationcollections were approved by the Office of Management and Budget, approval number 3150-0011, which expires on September 30, 2000.The public reporting burden for addressees who find it necessary to revise their response toGL 96-06 is estimated to average 40 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> per response, including the time for reviewinginstructions, searching existing data sources, gathering and maintaining the data needed, andcompleting and reviewing the collection of information. The U.S. Nuclear RegulatoryCommission 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 whether the information will have practical 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, including the use ofautomated collection techniques?Send comments on any aspect of this collection of information, including suggestions forreducing this burden, to the Information and Records Management Branch, T-6F33, 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 ofManagement and Budget, Washington, D.C. 20503.

GL 9606, Supplement 1November 13, 1997 If you have any questions about this matter, please contact the lead project manager or oneof the technical contacts listed below, or the appropriate Office of Nuclear Reactor Regulation(NRR) project manager for a specific nuclear power plant.Jack W. Roe, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts: James Tatum, NRR301-415-2805E-mail: jeti @nrc.govJohn Fair, NRR301-415-2759E-mail: jrfenrc.govLead Project Manager Beth Wetzel, NRR301-415-1355E-mail: baw@nrc.govAttachment: List of Recently Issued NRC Generic Letters4W4P jw UA

AttachmentGL 96-06, Supplement 1November 13, 1997 LIST OF RECENTLY ISSUED GENERIC LETTERSGenericI AA..Date oflean I-nrc. .wiSIce iel4 TnLVE.LM QUUIVL.L I ,12u

• I91-18, INFORMATION TO LICENSEESREV. 1 REGARDING NRC INSPECTIONMANUAL SECTION ON RESOLUTIONOF DEGRADED AND NONCONFORM-ING CONDITIONS97-04 ASSURANCE OF SUFFICIENTNET POSITIVE SUCTIONHEAD FOR EMERGENCYCORE COOLING ANDCONTAINMENT HEATREMOVAL PUMPS97-03 ANNUAL FINANCIAL SURETYUPDATE REQUIREMENTSFOR URANIUM RECOVERYLICENSEES97-02 REVISED CONTENTS OFTHE MONTHLY OPERATINGREPORT10108/9710/07/9707/09/9705/15/97ALL HOLDERS OF OLsFOR NUCLEAR POWERAND NPRs, INCLUDINGTHOSE POWER REACTORLICENSEES WHO HAVEPERMANENTLY CEASEDOPERATIONS, AND ALLHOLDERS OF NPR LICENSESWHOSE LICENSE NO LONGERAUTHORIZES OPERATIONALL HOLDERS OF OLsFOR NUCLEAR POWERPLANTS, EXCEPT THOSEWHO HAVE PERMANENTLYCEASED OPERATIONS ANDHAVE CERTIFIED THATFUEL HAS BEEN PERMAN-ENTLY REMOVED FROM THEREACTOR VESSELURANIUM RECOVERY LICENSEESAND STATE OFFICIALSALL HOLDERS OF OLsFOR NPRs, EXCEPT THOSEWHO HAVE PERMANENTLYCEASED OPERATIONS ANDHAVE CERTIFIED THATFUEL HAS BEEN PER-MANENTLY REMOVED FROM THEREACTOR VESSELOL = OPERATING LICENSECP = CONSTRUCTION PERMITNPR = NUCLEAR POWER REACTORS

GL 96-06, Supplement INovember 13, 1997 GL 96-06, Supplement 1November 10, 1997