ML20046B155
| ML20046B155 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/28/1993 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| 93-082A, 93-82A, NUDOCS 9308030186 | |
| Download: ML20046B155 (3) | |
Text
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VInGINIA Ei.ncruic Axe l'owru COMPANY llICIIMOND,VIItGINIA 20061 July 28, 1993 U.S. Nuclear Regulatory Commission Serial No.
93-082A Attention: Document Control Desk NL&P/JBL R0 Washington, D.C. 20555 Docket Nos.
50-338 50-339 License No.
NPF-4 NPF-7 Gentlemen:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNITS 1 AND 2 SUPPLEMENTAL INFORMATION REGARDING PROPOSED TECHNICAL SPECIFICATIONS CHANGES HIGH HEAD SAFETY INJECTION FLOW BALANCING By letter dated March 10, 1993, Virginia Electric and Power Company requested changes to the Technical Specifications for North Anna Power Station Units 1 and 2.
The proposed changes will revise the current Technical Specifications requirements pertaining to the high head safety injection system flow balance testing.
The attached supplementalinformation is provided in response to the questions asked during our conference call on July 27,1993. If you have any further questions, please contact us.
Very truly yours,
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U.S. Nuclear Regulatory Commission Region il 101 Marietta Street, N.W.
Suite 2900 Atlanta, Georgia 30323 NRC Senior Resident inspector North Anna Power Station Commissioner Department of Health Room 400 109 Governor Street Rlchmond, Virginia 23219 e
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f Additional Discussion in Support of the HHS! Flow Balance Testing l
Proposed Technical Specifications Change Request North Anna Power Station Units 1 and 2 1.
Summarize the small break LOCA analysis performed in support of the l
amendment request.
The small break LOCA analysis was performed using the NOTRUMP evaluation model (1), assuming high head safety injection flow rates from the two minimum flow branch lines which are equal to those contained in the proposed Technical Specification 4.5.2.h. The analysis was implemented as the analysis of record via a station 10 CFR 50.59 safety evaluation (2), per the provisions of Technical Specification 6.9.1.7, which specifies allowable LOCA analysis methodologies for establishing operating limits for key core parameters.
The results of the revised small break LOCA analysis were reported to NRC in Reference (3), which provided the required notification of change in the peak clad temperature (PCT) results for this transient. The PCT for the limiting case small break transient is 1873 F.
2.
Confirm that the revised pump runout flow remains bounded by the flow rate I
assumed in the analysis of the mass addition transient.
The total high head safety injection pump flow rate is limited to 660 gpm in proposed Technical Specification 4.5.2.h. In the existing analysis of record for the mass addition transient,705 gpm was assumed as the high head safety
=!
injection pump runout flow rate.
This analysis, submitted by letter dated December 27,1991, was approved via Reference (4).
i
References:
(1) WCAP-10054-P-A, " Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code," dated. August 1985 (Westinghouse Proprietary).
(2) " North Anna Power Station Units 1 and 2 - Implementation of Extended SGTP Small Break LOCA Analysis," 10 CFR 50.59 Safety Evaluation 92-SE-OT-005, dated January 21,1992.
(3) Letter from W. L. Stewart to USNRC, " Virginia Electric and Power Company -
North Anna Power Station Units 1 and 2 Report of Errors / Changes in Application of ECCS Evaluation Models Per Requirements of 10 CFR 50.46," Serial No.92-091, dated February 10,1992.
i (4) Letter from Leon B. Engle (NRC) to W. L. Stewart, " North Anna Units 1 and 2 l
Issuance of Amendments Re: Pressure / Temperature Operating Limits and Low Temperature / Overpressure Protection System Setpoints (TAC Nos. M83154 and M83155)," dated March 25,1993.
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