BVY-92-107, Submits Info Re Util Position on Leakage Detection,Per GL 88-01 & Suppl 1.Plant Procedures Modified by Incorporating Addl Leakage Monitoring,Per GL 88-01.Relocating 2 Gpm Requirement Into TS Not cost-effective Nor Justified

Submits Info Re Util Position on Leakage Detection,Per GL 88-01 & Suppl 1.Plant Procedures Modified by Incorporating Addl Leakage Monitoring,Per GL 88-01.Relocating 2 Gpm Requirement Into TS Not cost-effective Nor Justified

ML20106A662
Person / Time
Site:	Vermont Yankee
Issue date:	09/21/1992
From:	Murphy W VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-92-107, GL-88-01, GL-88-1, NUDOCS 9209290274
Download: ML20106A662 (3)

Text

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i 2, '!4 t ill September L'l,1992 United States Nuclear Regulatory Commission DVY 92 - 107 NITN: Document Control Desk Washington, DC 20M5

References:

a. License No. DPR 28 (Docket No. $0-271)

b. letter, USNRC to ( All Licensees), NVY 88-09, dated Februany 1,1988 (Generic letter 88-01).

c. letter, VYNPC to USNRC, FV Y 88 62, dated July 27,1988 (Response to Generic lxtter 88 01)

d. Letter, USNRC to VYNPC, NVY 89-114, dated May 24,1989 (NRC Request for Additional Infonnation regarding Generic letter 88 01)

e. letter, VYNPC to USNRC, llVY 89-70, dated July 25,1989 (VY Response to NRC Reg,uest for Additional lnfonnation)

f. letter, USNRC to VYNPL, NVY 90 026, dated February 14,1990 (NRC SER/TER regarding Review of VY GL 88-01 Response)

g. Letter, VYNPC to USNRC, llVY 90-26, dated March 8,1990 i (VY Position Conceming GL 88 01 leakage Detection) h, Letter, USNRC to l All Licensees) NVY 92 21, dated February 4,1992 (Supplement I to Generic letter 88 01)

1. letter, USNRC to VYNPC, NVY 92-89, dated May 22,1992 (USNRC response to VY Position Concerning OL t(8-01 leakage Detection)

Subject:

Generic letter 88-01, Position Concerning leakage Detection

Dear Sir:

In Reference (b), NRC issued Generic letter 88 01 which transmitted to licensees various staff positions relative to the occunence of 1GSCC in UWR stainless steel piping and requested licensees to respond to these staff positions in writing. Vennont Yankee tesponded to Generic Letter 88 01 via Reference (c). Relerences (d) and (c) transmitted an NRC sequest for additional infom1ation and Vennont Yankee's responses, respectively, reparding Vennont Yankee's response to Generic Letter 88 01. In Reference (f), NRC transmitted its Safety Evaluation Report (SER) stating that Vennont Yankee's response to Generic Letter 88-01 was acceptable, with the exception of VY's position concerning leakage detection. Vermont Yankee provided supplemental infonnation regarding our position via Reference (g).- Essentially, Vennont Yankee's position was that the 2 gpm requirements for unidentified leakage in primary containment were best handled administratively by plant operating pmeedures, and not in plant Technical Speci6 cations. Vennont Yankee modified plant procedures accordingly by incorporating the additional leakage monitoring requirements of Generic Letter 88-01.

In Reference (h), NRC issued Supplement I to Generic Letter 88-OL This document pmvided to licensees certain alternative stalf positions and clari0 cations to positions as provided by -

the original generic letter. Alternative Staff Position No. (7) from Reference (h) states the following:

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vel 4MOf J1 Y Af J KII NUCL E AR l'OWf:li COHI'Oll Al 10f J United States Nuclear llegulatory Conunission September 411992 Page 2 "GL 88-01 requested that the staffs position on leakage detection be incorporated into the TS of all affected licensees. The staff subsequently dete. mined that incorporation of the leakage detection requirements in an administrative document is not acceptable."

As a result of the clarincation p ovided in Supplement I to Generic Letter 68 01, NRC Staff responded to Vermont Yankee's Re'erence (g) submittal via Reference (i). In this letter, NRC concluded that Vennont Yankee has satisfactorily resolved all issues relating to Generie Letter 88-01, with the exception of Technical Specification requirements on unidentified leaksge. Reference (i) provided a determination that Vennont Yankee procedure OP 4152 has acceptable action requhements, except for the words " averaged over" the previous 24 hout period. In addition, Reference (i) provided a determination that the limits on unidentified leacage must be in the Technical Specifications. Accordingly, Reference (i) requested Vermont Yankee to submit 4

,roposed Technical Specifications to address this issue within 120 days (or advise the NRC Project Manager as to when Vennont Yankee expects to make such a submittal). NRC rei:rrated -

its request for a proposed change to Technical Specifications in a m-eting held at NRC headquaners in Rockville Maryhtnd on August 5,1992.

Vennont Yankee believes that the words " averaged over" as utilized in plant arocedure OF 4152 are appropriate to detect the conditions of concern in Generic Letter 88-01 ( .e. IGSCC in reactor coolant piping). Previous discussions with your Staff have highlighted a cor.cern that unidentified reactor coolant leakage could spike to 2 ppm or higher and then decrease within a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, as might be postulated in the case of a valve packing leak where the valve is stroked and backseated resulting in reduced leakage. In this case, the averaging method utilized in OP '

4152 would not identify a leak rate increase of 2 gpm or higher, since the leakage rate would be averaged over 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. Ilowever,it must be underscored that the types of leakage which could spike and then diminish are outside the scope of Generic Letter 88-01. We know of no mechanism that would cause a potential crack in reactor coolant piling caused by 1GSCC under constant l pressure to diminish once a through-wall crack is initiatec. lienee, the averaging method utilized in OP 4152 would detect unidentified leakage of reactor coolant piping caused by IGSCC, in _

accordance with Generic Letter 88-01. Our previous sul mi'tals detail the other means that are available and are utilized at Vennont Yankee to detect ah types of leakage in contairment (e.g.

containment pressure detection, drywell temperature monitoring, containment particulate monitoring, drywell sump 1; vel instrumentation).

With regard to Technical Specification requirements, Vermont Yankee has carefully considered NRCs request to place 11e 2 gpm leakage detection requirement of Generic Letter 88-01 into the plant Technical Specifications and has detennined cuch a requirement clearly constitutes a backfit as defined in 10CFR50.109.

Generic Letter 88-01 and Supplement 1 (References (b) and (h), respectively] cite compliance with the General Design Criteria of 10CFRf'), Appendix A (specifically, GDCs 4,14,30,31, and

32) as NRCs basis for not perfonning a backfit analysis as required by 10CFR50.109. Vennont Yankee fully meets these GDC regmrements without a change to Technical Specifications. As discussed in our previous submittals on this issue, Vennont Yankee's Technical Specifications presentl y contain specific limits on unidentified leakage in containment. Vennont Yankee has modified its procedures to include the 2 gpm reactor coolant leakage detection requirement of Generic Letter 88 01 and specifically references Generic Letter 88-01 as the basis for such a requirement. Rekicating the 2 gpm requirement from plant procedures into the plant Technical Specifications would yield no improvement in plant safety, nor would it have any effect on the

1

. VERMONT YANKEE NUCt. EAR POWER CORPOR ATION

'I

- United States Nuclear Regulatory Commission September 21.1992 Page 3 health and safety of the public or the common defense and security; yet the costs associated with preparation, submittal, review, approval, and implementation of such a proposed chan e to the plant Technical Specifications are significant. Our experience has been that even the sh est of proposed changes to the plant Technical Specincations incurs an associated cost of at least 20,0(X) m NRC billable charges alone, not including Vermont Yankee's time to prepare, submit and implement the change. We feel that these are costs which in this case are not justified by any decernable improvement relative to phnt safety. -;

Vennont Yankee respectfully requests that NRC reconsider the:r request of Reference (i) as the subject of a formal backSt analysis as required by 10CFR50.109. _ Should such a backfit analysis conclude that NRCs request is in fact justified, then Vennont Yankee will prepare and submit the requested proposed Technical Specification change.

We would be happy to discuss this issue with your Staff further, at your convenience.

Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION h ,

Warren P. M rphy SeniorVice'l esident O rht' ns

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(v: USNRC Rer en 1 Administrator USNRC Resident inspector- VYNPS USNRC Project Manager - VYNPS I

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