ML20063P573

Safety Evaluation Supporting Amend 9 to License NPF-10

ML20063P573
Person / Time
Site:	San Onofre
Issue date:	10/07/1982
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20063P570	List: ML20063P569 ML20063P573
References
NUDOCS 8210130577
Download: ML20063P573 (2)

Text

h SAFETY EVALUATION AMENDMENT 9 to NPF-10 SAN ONOFRE NUCLEAR GENERATING STATION, UNIT 2 DOCKET H0. 50-361 Introduction By letter dated September 30, 1982, the ifcensees requested that Technical

~ Specification 3.3.4 be modified to allow operation in MODES 2 and 3 with the turbine overspeed protection systen inoperable, provided that the main steam isolation valves and their bypass line valves remain fully closed.

Evaluation In their letter of Septenber 30, 1982, the licensees state that the basis for the turbine overspeed protection system limiting condition for operation is to ensure that the probability of turbine missiles being generated is acceptably low. The present Limiting Condition for Operation (LCO) of Technical Specification 3.3.4 requires the overspeed protection system to be operable when the plant is in MODES 1, 2, and 3.

The proposed LCO allows continued operation in MODES 2 and 3 with the MSIYs and HSIV bypass valves shut when the overspeed protection system is inoperable. The turbine is normally operated in MODE 1 (power above 5%); however isolation of steam from the turbine is feasible in MODES 2-and 3, thus precluding a turbine missile potential due to overspeed.

We have evaluated the proposed change and conclude that it provides protection against turbine overspeed that is comparable to the existing LCO, and, therefore, find it to he acceptable.

Environnental Consideration l

We have determined that this amendment does not authorize a change in effluent types or total amount nor an increase in power level and will not result in any l

significant environmental impact. Having made this determination, we have further concluded that this amendment involves action which is insignificant from the standpoint of environmental inpact, 'and, pursuant to 10 CFR Section 51.5(d)(4), that an environmental impact statement or negative declaration L

and environnental impact appraisal need not be prepared in connection with the j

issuance of this amendment.

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-Conclusion Based upon our evaluation of the proposed change to the San Onofre, Unit 2 Technical Specifications, we have concluded that:

(1) because this amendment does not involve a significant increase in the probability or consequences of accidents previously considered, does not create the possibility of an accident of a type different from any evaluated previously, and does not involve a significant decrease in a safety margin, this amendment does not involve a significant safety hazards consideration; -(2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed nanner, and (3)- such activities will be conducted in compliance with the Commission's regulations and the issuance of this acendment will not.be ininical to the comnon defense and security or to the health and ' safety of the public. We, therefore, conclude that the proposed changes are acceptable.

Dated:

OCT 71982 t

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