ML20205N269

Safety Evaluation Supporting Amends 151 & 143 to Licenses NPF-10 & NPF-15,respectively

ML20205N269
Person / Time
Site:	San Onofre
Issue date:	04/09/1999
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20205N265	List: ML20205N260 ML20205N269
References
NUDOCS 9904160214
Download: ML20205N269 (3)

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p uam gl UNITED STATES 3

S NUCLEAR REGULATORY COMMISSION f

WASHINGTON, D.C. 2051 5 0001

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.151 TO FACILITY OPERATING LICENSE NO. NPF-10 AND AMENDMENT NO.143 TO FACILITY OPERATING LICENSE NO. NPF-15 SOUTHERN CALIFORNIA EDISON COMPANY SAN DIEGO GAS AND ELECTRIC COMPANY i

THE CITY OF 31VERSIDE. CALIFORNIA THE CITY OF ANAHEIM. CALIFORNIA SAN ONOFRE NUCLEAR GENERATING STATION. UNITS 2 AND 3 DOCKET NOS. 50-361 AND 50-362

1.0 INTRODUCTION

j By application dated January 24,1997, Southern California Edison Company, et al. (SCE or the licensee) requested changes to the Technical Specifications (Appendix A to Facility Operating License Nos. NPF-10 and NPF-15) for the San Onofre Nuclear Generating Station, Unit Nos. 2 and 3. The proposed changes would revise Surveillance Requirement 3.8.1.9 to Technical t

Specification 3.8.1,'AC Sources-Operating". This would provide more limiting emergency diesel generator (EDG) voltage and frequency limits for recov'ry from the transient caused by the single largest post-accident load rejection test. The voltage and frequency limits are made tighter, to accurately reflect plant design requirements.

2.0 EVALUATION Surveillance Requirement 3.8.1.9 (SR) currently requires that the licensee:

Verify each EDG, when operating with design basis kW loading and maximum kVAR loading permitted during testing, rejects a load a 682 kW, and:

a.

Following load rejection, the frequency is s 66.75 Hz; b.

Within 4 seconds following load rejection, the voltage is a 3924 V and s 4796 V; and I

c.

Within 4 seconds f ing load rejection, the frequency is a 58.8 Hz and s 61.2 Hz.

9904160214 990409 i

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' The licensee has proposed to revise SR 3.8.1.9 as follows:

Verify each EDG rejects a load gmater than or equal to its associated single largest post-ac%e t load, and:

a.

Following load rejection, the frequency is s 66.75 Hz; b.

.Within 4 seconds following load rejection, the Voltage is 2 4297 V and s 4576 V; and c.

Within 4 seconds following load rejection, the frequency is a 59.7 Hz and s 61.2 Hz.

The proposed technical specification change provides more limiting voltage and frequency limits for recovery from the transient caused by the single largest post-accident load rejection test. Tne voltage and frequency limits are made tighter, to accurately reflect the assumptions made in the San Onofre accident analysis. The lower voltage is changed to 4297 V because this is the voltage that the EDG must achieve to reset the 4.16 kV engineered safety features (ESF) bus undervoltage relays to allow ESF load sequencing to proceed. Undervoltage relay reset is a permissive that must be satisfied to initiate load sequencing.

The upper limit is changed to 4576 V to be consistent with the maximum allowable steady state voltage for 4.16 kV motors (110 percent of 4160 V). The previous voltage limits were based on EDG run conditions of 4360 Vi 10 percent.

The lower frequency limit is changed from 58.8 Hz to 59.7 Hz. The lower frequency limit is equal to -0.5 percent of the 60 Hz nomina! frequency and based on maintaining acceptable high pressure safety injection system performance as assumed in the accident analyses.

In order to ensure that the EDG is tested under load conditions that are as close to design basis conditions as possible, testing is performed by rejecting an inductive load with kW and kVAR greater than or equal to the single largest post-accident load (683 kW,369 kVAR). These test conditions are consistent with the power factor requirements of Regulatory Guide 1.9 Rev. 3,

• Selection, Design, and Qualification of Diesel-Generator Units Used as Standby (Onsite)

Electric Power Systems at Nuclear Power Plants."

The ctaff concludes that the proposed voltage and frequency specified for recovery from the transient caused by the single largest post-accident load rejection are conservative in that the j

voPr.ge and frequency limits are made tighter to ensure: (1) the limits are consistent with the i

design range of the equipment powered by the EDG, and (2) the EDG continues to function as assumed in the San Onofre accident analysis. Further, rejection of an inductive load of with kW i

and kVAR greater than or equal to 683 kW and 369 kVAR make the test conditions consistent with the power factor requirements of Regulatory Guide 1.9, Rev. 3. Therefore, the proposed 3

change is acceptable.

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3.0 STATE CONSULTATION

In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendments. The State official had no comments.

4.0 ENVIRONMENTAL CONSIDERATION

The amendments change a surveillance requirement. The NRC 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 y

individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such hding (63 FR 6997). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmentalimpact statement or environmental assessment need be prepared in connection with the issuance of the amendments.

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5.0 CONCLUSION

The Commission has concluded, bLsed on the considerations discussed above, that (1) there is reasonable tissurance 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: O. Chopra, EELB Date:

April 9, 1999 l

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