ML18100A593
| ML18100A593 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/25/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18100A592 | List: |
| References | |
| NUDOCS 9309090443 | |
| Download: ML18100A593 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION ENCLOSURE WASHINGTON, D.C. 20555--0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATING TO SMALL BREAK LOCA ANALYSIS USING
1.0 INTRODUCTION
NOTRUMP COMPUTER CODE SALEM GENERATING STATION, UNITS 1 AND 2 DOCKET NOS. 50-272 AND 50-311 By letter dated April 2, 1993, Public Service Electric and Gas Company (PSE&G}, the licensee for Salem Nuclear Generating Station (SNGS}, Units 1 and 2, submitted the Small Break Loss of Coolant Accident (SBLOCA} Analysis Report, WCAP-13657.
WCAP-13657 incorporates the NOTRUMP computer code which is a one-dimensional general network code that replaces the WFLASH technology.
The NOTRUMP SBLOCA emergency core cooling system (ECCS} Evaluation Model was developed to determine the reactor coolant system (RCS} response to design basis SBLOCAs, and to address NRC concerns expressed in NUREG-0611.
The NOTRUMP code was approved by the staff, in 1985, for evaluating SBLOCA for Westinghouse NSSS designs.
- 2. 0 EVALUATION Westinghouse, on behalf of the licensee, reanalyzed the SBLOCA analysis using NOTRUMP to demonstrate that SNGS conforms with 10 CFR 50.46 for the conditions associated with the Fuel Upgrade/Margin Recovery Program.
The following parameters were incorporated into the analysis:
- core power of 3411 MWt, Fgr=2.4, FAH=l.65
- vessel average operating temperature from S66°F to 580°F, with +/-5°F allowance for uncertainties
- uniform steam generator tube plugging of 25%
RCS pressure of 2300 psia with +50 psia allowance for uncertainties
- thermal design flow of 82500 gpm, and PERFORMANCE+, VANTAGE-SH, and STANDARD (275 psig backfill} fuel.
In order to determine the conditions that produce the most limiting SBLOCA case, a total of five cases were examined by Westinghouse.
The break sizes analyzed include 4, 3, 2 and 1.5 inch diameter cold-leg-break based on a vessel average temperature of 580°F, during full power operation.
The resulting peak cladding temperatures (PCT}, listed below, indicate the 2.0-inch break as the most limiting condition.
Break size Cinches) 4.0 3.0 2.0 1.5 PCT (°F) 1343 1508 1580 580 The vessel average temperature sensitivity was performed, using the 2.0-inch limiting break size, to support a vessel average temperature of 566°F.
The resulting PCT of 1558°F indicates that the high vessel average temperature, of 580°F, as most limiting.
3.0 CONCLUSION
The licensee performed a four break spectrum that including the 1.5, 2, 3, and 4-inch breaks.
The most limiting small break was the 2-inch equivalent diameter cold leg break which resulted in a calculated peak cladding temperature of 1580°F.
An additional analysis was performed to identify the limiting condition for the vessel temperature, in the allowable operating range.
The limiting condition was determined to be the high RCS average temperature, TAvG=580°F.
The licensee performed the analysis with an evaluation model based on the approved Westinghouse 1985 generic SBLOCA ECCS Evaluation Model incorporating NOTRUMP analysis technology.
The staff finds the licensee's analysis
- acceptable in that the licensee has demonstrated that SNGS meets the acceptance criteria of 10 CFR 50.46.
Principal Contributor: S. Brewer Date: August 25, 1993
',. REFERENCES
- 1.
Letter from J. J. Hagan, Public Service Electric and Gas Company, to U.S.
NRC, "Small Break Loca NOTRUMP Analysis Report Salem Generation Station, Unit Nos. 1 and 2," dated April 2, 1993.
- 2.
WCAP-13657, * (Westinghouse), "Sal em Uni ts 1 & 2 Sma 11 Break LOCA NOT RUMP Analysis Engineering Report in Support of the Fuel Upgrade / Margin Recovery Program," dated March 1993.
- 3.
Letter from C. 0. Thomas, Westinghouse, to NRC, "Acceptance for Referencing of Licensing Topical Report WCAP 10054(P)," "Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code," dated May 1985.