ML18039A696

Provides Util Response to GL 95-07 Re RCIC Sys Injection Valves (2/3-FCV-71-39) for BFN Units 2 & 3.Previous Responses,Dtd 951215,1016 & 960730,0315 & 0213,supplemented

ML18039A696
Person / Time
Site:	Browns Ferry
Issue date:	02/19/1999
From:	Abney T TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-95-07, GL-95-7, TAC-M93437, TAC-M93438, NUDOCS 9903040349
Download: ML18039A696 (10)

Text

CATEGORY 1 REGULA1 RY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9903040349 DOC.DATE: 99/02/19 NOTARIZED: NO DOCKET' SCIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 50-2'96 Browns Ferry Nuclear Power Station, Unit 3, Tennessee 05000296 AUTH. NAME AUTHOR AFFILIATION ABNEY,T.E. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Records Management Branch (Document Control 95-07,re reactor core Desk)'UBJECT:

Submi;ts supplemental response to GL isolation cooling (RCIC)'ys'njection valves (2/3-FCV-71-39) for BFN,Units 2 E 3.

DISTRIBUTION CODE: A056D TITLE: Generic Ltr COPIES RECEIVED:LTR 95 Pressure Locking &

/ / SIZE:

ENCL Thermal Binding of Safety Rely T

NOTES:

RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR' ENCL ID CODE/NAME LTTR ENCL NRR/DRPE/EATON 1 PD2-3-PD 1 1 DEAGAZIO,A 1 1 INTERNAL: E CENTER 1 1 NRR/DE/EMEB/B 1 1 EXTERNAL: NOAC 1 1 NRC PDR 1 1 NUDOCS ABSTRACT 1 1 D

NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WASTE. TO HAVE YOUR NAME OR ORGANIZATION REMOVED FROM DISTRIBUTION LISTS OR REDUCE THE NUMBER OF COPIES RECEIVED BY YOU OR YOUR ORGANIZATION, CONTACT THE DOCUMENT CONTROL DESK (DCD) ON EXTENSION 415-2083 TOTAL 'NUMBER OF COPIES REQUIRED: LTTR 8 ENCL 8

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Tennessee Valley Authority, Post Office Box 2000. Decatur. Alabama 36609 February 19, 1999 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter of Docket Nos. 50-260 Tennessee Valley Authority 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) UNI TS 2 AND 3 GENERIC LETTER (GL) 95 07 I PRESSURE LOCKING AND THERMAL BINDING OF SAFETY-RELATED POWER-OPERATED GATE VALVES SUPPLEMENTAL RESPONSE (TAC NOS. M93437 AND M93438)

This letter provides TVA's response to GL 95-07 regarding the Reactor Core Isolation Cooling (RCIC) System injection valves (2/3-FCV-71-39) for BFN Units 2 and 3. This letter supplements previous TVA responses to GL 95-07 dated July 30, 1996, March 15, 1996, February 13, 1996, December 15, 1995, and October 16, 1995.

TVA's original evaluation performed for GL 95-07 stated that the RCIC injection valves 2/3-FCV-71-39 may be susceptible to pressure locking, but that no modifications were required since this valve does not perform a safety-related function. The evaluation was based on the fact that RCIC is not considered a "safety-related" system at BFN, since it is only required to operate in response to anticipated operational transients (AOTs), such as loss of feedwater events. Also, at the time of TVA's original response to GL-95-07, the valve was not considered part of the GL 89-10 safety related MOV program scope for the same reason.

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0 U.S. Nuclear Regulatory Commission Page 2 February 19, 1999 Subsequently, TVA included the valves in the BFN GL 89-10 MOV program as part of the resolution of the MOV program scope issue raised by NRC. This valve was added to the MOV program not because it was considered safety-related, but because the RCIC system is required to mitigate other licensing basis events such as Appendix R and Station Blackout events.

During the review of BFN's response to GL 95-07, NRC raised questions regarding the BFN evaluation for pressure locking/thermal binding of several BFN MOVs. Each of the questions raised was satisfactorily resolved with the exception of the susceptibility for pressure locking of the RCIC injection valves 2/3-FCV-71-39. The NRC reviewer stated that GL 95-07 requires licensees to evaluate other valves outside the scope of the GL based on other licensing commitments. The BFN licensing basis includes the ability for the RCIC system to mitigate AOTs such as loss of feedwater events, Anticipated Transient Without Scram (ATWS), Appendix R, and Station Blackout events.

As a result of the NRC concern described above, TVA has reconsidered its original response to GL 95-07 for RCIC injection valves, 2/3-FCV-71-39. Based on its review, TVA has determined that the valves in question are required for mitigation of certain licensing basis events. The event which could potentially cause a pressure locking condition for the 2/3-FCV-71-39 valves is a loss of all feedwater event which is classified as an AOT.

Therefore, based on the above, TVA is including the BFN Units 2 and 3 RCIC Injection valves (FCV-71-39) in the GL 95-07 program scope. TVA will modify the BFN Units 2 and 3 RCIC injection valves, FCV-71-39 (flexible wedge gate valve), by dry;lling the disk. This modification will eliminate the possibility for pressure locking of the valves. For Unit 2, the modification will be completed prior to restart from the Cycle 11 (Spring 2001) refueling outage. For Unit 3, the modification will be completed prior to restart from the Cycle 9 (Spring 2000) refueling outage.

In the interim, current plant procedures require that the RCIC System be vented and the 2/3-FCV-71-39 valves stroked on a monthly basis. TVA has also identified the potential

U.S. Nuclear Regulatory Commission Page 3 February 19, 1999 for pressure locking of the 2/3-FCV,-71-39 valve in its corrective action program. An operability evaluation has been performed and concluded that the 2/3-FCV-71-39 valves are operable.

If you729-2636.

have any questions, please contact me at (256) ncerel ey

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Manager of 'nse g and In stry Aff irs Enclosure cc (Enclosu Mr. Paul . drickson, Branch Chief U.S. Nuclear Regulatory Commission Region II 61 Forsyth Street, S.W.

Suite 23T85 Atlanta, Georgia 30303 NRC Resident Inspector Browns Ferry Nuclear Plant 10833 Shaw Road Athens, Alabama 35611 Mr. L. Raghavan, Project .Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

0 ENCLOSURE TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)

UNITS 2 AND 3 GENERIC LETTER 95-07, PRESSURE LOCKING AND THERMAL BINDING OF SAFE TY-RELATED POWER-OPERATED GATE VALVES SUPPLEMENTAL RESPONSE COMMITMENT

SUMMARY

TVA will modify the BFN Unit 2 Reactor Core Isolation Cooling (RCIC) injection valve, 2-FCV-71-39 (flexible wedge gate valve), by drilling the disk. The modification will be completed prior to restart from the Cycle 11 (Spring 2001') refueling outage.

2. TVA will modify the BFN Unit 3 Reactor Core Isolation Cooling (RCIC) injection valve, 3-FCV-71-39 (flexible wedge gate valve), by drilling the disk. The modification will be completed prior to restart from the Cycle 9 (Spring 2000) refueling outage.

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