ML20246L151

Safety Evaluation Supporting Amends 74 & 62 to Licenses NPF-10 & NPF-15,respectively

ML20246L151
Person / Time
Site:	San Onofre
Issue date:	06/30/1989
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20246L143	List: ML20246L138 ML20246L151 ML20246L162
References
NUDOCS 8907180354
Download: ML20246L151 (3)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.74 TO FACILITY OPERATING LICENSE NO. NPF-10 AND AMENDMENT NO.62 TO FACILITY OPERATING LICENSE NO. NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY THE CITY OF RIVERSIDE, CALIFORNIA THE CITY OF ANAHEIM, CALIFORNIA SAN ON0FRE NUCLEAR GENERATING STATION, UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362

1.0 INTRODUCTION

By letter dated December 29,)1988, Southern California Edison Company (SCE), et al. (the licensees, requested a change to the Technical S)ecifications for Facility Operating Licenses No. NPF-10 and No NPF-15 t1at authorize operation of San Onofre Nuclear Generating Station (SONGS),

Units 2 and 3 in San.Diego County, California. This request, designated as PCN-253, proposed to extend the interval for required 18 month surveillance tests in order to support the nominal 24 month fuel cycle. Both Units 2 and 3 are operating in their first such cycle and will have to shut down to perform the 18 month surveillance unless the required interval is extended. SCE has submitted proposed changes to ccver all the 18 month surveillance tests which cannot be performed during plant operation. Many of these requests would have changed the required interval from "at least once every 18 months" to "at least once per refueling outage." By lctter dated March 20, 1989, SCE amended these requests to define " refueling outage" as 24 months. This definition has been included in the Frequency Notation tableoftheTechnicalSpecifications(Table 1.2)byAmendments73and61 to Licenses No. NPF-10 and No. NPF-15, respectively.

2.0 DISCUSSION AND EVALUATION By letter dated December 29, 1988, the licensees proposed to change Technical Specification 3/4.8.2, "DC Sources," to extend the 18 month 8907i80354 890630 P/

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,,.,. surveillance interval to at least once per refueling outage (24 months).

This Specification requires operability of the four 125 VDC battery banks l'

and their associated battery chargers in modes I through 4, defines periodic surveillance tests and inspections to verify operability, and specifies compensatory action to be taken when a battery bank or its associated charger is found to be inoperable.

I The operability of the DC power sources during operation ensures that l

sufficient power is available to supply the safety related equipment required for safe shutdown of the facility and for mitigation and control of accident conditions within the facility. Surveillance Requirement 4.8.2.1.c requires visual inspections, resistance measurements, and battery charger capacity. checks at least once per 18 months. Surveillance Requirement 4.8.2.1.d requires verifying at least once per 18 months that the battery capacity is adequate to supply and maintain in operable status all actual or simulated emergency loads for the design duty cycle when the battery is subjected to a battery service test.

SCE states that a review of the required 18 month surveillance tests from the beginning of commercial operation to the present has determined that these tests have never detected a bad cell, bad connection, or any other failure. Tests of the battery chargers have confirmed that their capacity is adequate. Weekly and quarterly surveillance tests of the batteries check the electrolyte level, voltage, specific gravity, and general condition of each pilot cell and each connected cell, respectively. Existing weekly and quarterly tests are not affected by this change.

The staff has evaluated the licensees' submittal and has found that the proposed change affects only the frequency of the 18 month surveillance tests of the batteries and battery chargers, which may cause a reduction in confidence in battery operability and in the associated margin of safety.

However, weekly and quarterly surveillance tests will continue to provide a measure of battery capability.

In addition, Technical Specification 4.0.2 allows the current 18 month interval to be extended by 25%, to 22.5 months.

For these reasons, and because the 18 month surveillance tests have not detected any failures, any reduction in confidence in battery operability is expected to be small for an increase from the currently allowable 22.5 months to 24 months. Therefore, a surveillance interval of 24 months is acceptable. However, the 25% extension of the surveillance interval allowed under Technical Specification 4.0.2 will no longer be permitted for this specification. The staff has allowed a one time extension of the surveillance interval of up to 60 days for Cycle 4 only. This extension is contingent upon successful completion of the quarterly surveillance test prior to exceeding 24 months. The quarterly surveillance test provides sufficient confidence in battery condition to allow an increase of an additional 60 days (beyond completion of the quarterly surveillance test) in the surveillance interval.

However, this allowance may be applied only once so that the total surveillance interval does not exceed 26 months.

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. 3.0. CONTACT WITH STATE OFFICIAL l

The NRC staff:has advised the Chief of the Radiological Health Branch, State Department of Health Services, State of California, of the'propoF2d determination-of no'significant hazards consideration. No comments w2re received.

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4.0 ENVIRONMENTAL CONSIDERATION

Pursuant to 10 CFR Part 51.21, 51.32, and 51.35, an environment'l assessment and finding of no significant impact have been prepared and published (54 FR-

);in the-Federal Register on Accordingly,

. based upon the environmental assessment, the Commission had determined that the issuance of this amendment'will not have a significant effect on the quality of the human environment.

5.0 CONCLUSION

.We have concluded, ba' sed on the considerations discussed above,-that:

-(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributor:

N. Trehan Dated: June 30,1989

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