ML20054F008

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Responds to NRC Ltr Re Violations Noted in IE Insp Rept 50-334/82-02.Existing Leak Rate Test Procedure Adequately Conservative to Meet Intent of Tech Specs
ML20054F008
Person / Time
Site: Beaver Valley
Issue date: 04/19/1982
From: Carey J
DUQUESNE LIGHT CO.
To: Haynes R
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20054F005 List:
References
NUDOCS 8206150130
Download: ML20054F008 (3)


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  • Wr h5 Duquesnel@t Telephone (412) 4564000 Nuclear Division P.O. Box 4 Shippingport, PA 150774004 April 19, 1982 United States Nuclear Regulatory Commission Office of Inspection and Enforcement Attn: R. C. Haynes, Regional Administrator Region I 631 Park Avenue King of Prussia, Pennsylvania 19406

Reference:

Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 RCS Unidentified Leakage Detection Limits [ Technical Specifica tion 3.4.6.1]

Centlemen:

During a recent inspection by Reginn I Inspection and Enforcement personnel at our facility, documented in Inspection Report 82-02, we were requested to revise our leak rate test procedure and correct the unidenti-fled leak rate mass to a temperature corresponding to the nominal cold leg value to comply with the technical specification limit of 1 GPM.

In conference between J. W. Chung of your staff and K. D. Grada of Duquesne Light, an NRC position was quoted which requires that this mass conversion be based on the cold leg density. The basis for this require-ment has apparently been extracted from an internal Region II memorandum dated August 14, 1980 from Messers D. C. Kirkpatrick, R. W. Woodruff to E. L. Jordan.

Our procedure currently requires that the mass conversion be corrected for 120F versus operating temperatures. We have taken this approach for the following reasons:

1. Typically, engineering expressions which give a "GPM" equivalent are based on standard temperature and pressure conditions. We believe our 120F density correction is conservative in this respect since this is the nominal temperature of water within the bulk of the charging system and well above our allowable limit for contain-ment temperatures.
2. If we corrected the unidentified leakage mass to operating condi-tions and the leak was actually within the lower temperature charg-ing system, the allowable limit would be reduced by approximately 37% due to the density correction such that a shutdown would be required at a .63 gpm unidentified leak rate versus the nominal I gpm. While we recognize that this correction factor will give F206150130 820608 P

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. 6 Beaver Valley Power Station, Unit No.1 Docket l'o. 50-334, License No. DPR-66 RCS Unidentified Leakage Detection Limits [ Technical Specification 3.4.6.1]

April 19, 1982 Page 2 an " apparent" increased limit in the allowable 1 gpm leak rate (if the elevated density correction factor is utilized), it is our position that the technical specification's 1 gpm limit on unidentified leak rate was based on S.T.P conditions to pro-vide for a " detectable mass loss" within the constraints of detection systems' sensitivity and the operator's ability to measure the relative change in inventory and flow rates. We currently require identification of leakage within the contain-ment, if the containment sump flow increases by 50%, or, if the steady state sump flow exceeds 2 gpm.

3. The technical specification basis for the I gpm reactor coolant leak rate limit was drawn from Regulatory Guide 1.45 " Reactor Coolant Boundary Leakage Detection System" dated May 1973. The paragraph which describes " Detector Sensitivity" infers that the limits are based on STP conditions since " monitoring changes in sump water level, flow rate or pump operating frequency" for ".5-1 gpm changes" suggests atmospheric conditions. Inaccuracies at this magnitude are implied as being acceptable in paragraph "C",

" Regulatory Position" whereby " Leakage to the Primary Reactor Con-tainment from unidentified sources should be collected and flow rate monitored with an accuracy of 1 gpm or better."

4. There is no substantial technical basis to justify the utilization of the elevated temperature density correction factor since the maximum error introduced would only provide for a +.37 gpm error above the I gpm limit, if all unidentified leakage was from the high temperature system. We have reviewed test data prepared by different utilities and found our density correction factor to be conservative.

Uc do not believe that a significant basis exists to justify a revision to the existing procedure since the selected value of I gpm has no basis in the safety analysis.

5. The FSAR, Section 4.2.7 clearly identifies the sensitivity of the BVPS Leakage Detection System and addresses this deviation from Regulatory Guide 1.45. WCAP 7503, Revision 1, " Determination of Design Pipe Breaks for Westinghouse Reactor Coolant Systems" clearly shows that our limit is less than that required for purposes of detecting critical through-wall cracks.

. ,+ .

Beaver Valley Power. Station, Unit No. 1

. Docket No. 50-334, License No. DPR-66 RCS Unidentified Leakage Detection Limits [ Technical Specification 3.4.6.1] _

April 19, 1982 Page 3 We believe that our existing procedure is adequately conservative to meet the intent of the Technical Specifications.

Very trt y yours, J. J. Carey Vice President, Nuclear I

cc: Mr. D. A. Beckman, Resident Inspector U. S. Nuclear Regulatory Commission Beaver Valley Power Station Shippingport, PA 15077 U. S. Nuclear Regulatory Commission I c/o Document Management Branch Washington, DC 20555 i

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