ML20236U463
| ML20236U463 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/17/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20236U462 | List: |
| References | |
| TAC-66001, TAC-66002, NUDOCS 8712030071 | |
| Download: ML20236U463 (2) | |
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r nogjo UNITED STATES g
NUCLEAR REGULATORY COMMISSION
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WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 62 TO FACILITY OPERATING LICENSE NO. NPF-10 AND AMENDMENT NO. 51 TO FACILITY OPERATING LICENSE NO. NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY, ET AL.
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SAN ONOFRE NUCLEAR GENERATING STATION, UNITS 2 & 3 DOCKET NOS. 50-361 AND 50-362 l
1.0 INTRODUCTION
By letters dated August 5, 1987 and September 18, 1987, Southern California Edison Company (SCE), the managing licensee, submitted a proposed change to the San Onofre Nuclear Generating Station (SONGS) Units 2 and 3 Technical Specifications.
The proposed change would revise Technical Specification 3/4.2.7, " Axial Shape Index" and its associated Bases by revising the numerical limits of axial shape index (ASI) when it is monitored with the core operating limit supervisory system (COLSS).
The Surveillance Require-ment associated with this specification would also be revised to require the core average ASI to be monitored continuously when using COLSS to assure that it is within its alarm limit.
The ASI is defined as the power generated in the lower half of the core less the power generated in the upper half of the core divided by the sum of these powers and can be calculated using either the COLSS or any operable core protection calculator (CPC) channel.
2.0 EVALUATION DESCRIPTION Technical Specification 3/4.2.7 currently states that the ASI must be main-tained within the limits of -0.28 to +0.28 when monitoring with the COLSS.
The COLSS continuously calculates the ASI and compares the calculated value to that established for the COLSS ASI alarm limits.
These limits are based on the range assumed in the safety analyses (-0.3 to +0.3) and reduced by the ASI uncertainty of 10.02 calculated for Cycle 3.
This uncertainty will increase to 10.03 for Cycle 4 due primarily to the effect of increased cycle length on the measurement uncertainties associated with the incore detectors which supply input to the COLSS.
To reflect this change, the Technical Specification limits are changed to -0.27 to +0.27 for Cycle 4 and subsequent cycles of operation.
The staff has reviewed the proposed change and finds it accept-able because it constitutes an additional restriction on plant operation that is necessitated by the extended duration of Cycle 4 and subsequent cycles.
The staff also concludes that the change to the surveillance requirement, TS 4.2.7, to require continuous monitoring of the core average ASI when using COLSS, is also more restrictive than the current requirement for monitoring once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and is acceptable.
8712030071 071117 PDR ADOCK 05000361 p
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' 3.0 CONTACT WITH STATE OFFICIAL The NRC staff has advised the Chief of the Radiological Health Branch, State Department of Health Services, State of California, of the proposed determina-tion of no significant hazards consideration. No comments were received.
4.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes to the installation or use of facilities' components located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements. The staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational exposure. The NRC staff has made a dett.mination that the amendments involve no significant hazards consideration, and t%rc has been no public coment on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR i
51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.
5.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operaton in the proposed manner, and (2) such activities will be conducted in compliance with the Comission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
L. Kopp H. Rood Dated:
November 17, 1987 i
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