ML20031D175

Safety Evaluation Supporting Amend 5 to License NPF-9

ML20031D175
Person / Time
Site:	McGuire
Issue date:	09/23/1981
From:	Office of Nuclear Reactor Regulation
To:
Shared Package
ML20031D173	List: ML20031D172 ML20031D175 ML20031D176 ML20031D177 ML20031D178
References
TAC-46812, NUDOCS 8110130027
Download: ML20031D175 (2)

Text

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO N4ENOMENT I;0. 5 TO LICENSE NPF-9 DUKE POWER COMPANY INTRODUCTION By letter dated September 21, 1981, the licensee (Duke Power Company) proposed a nodification to the Technical Specification for the McGuire Nuclear Station, Unit 1, regarding the setpoint associated with the reactor trip initiated by a turbine trip.

The design of the Turbine Trip / Reactor Trip circuit is based on the control oil system which is used to control the Digital Electro-Hydraulic (DEH) system oil pressure through an interface valve. When a turbine trip signal is initiated, a section of the control oil system is bled off which in turn dunps the pressure on the DEH system to close the turbine control and stop valves. This control oil system generates a low pressure signal at 45 psig through 2 out of 3 logic to trip the reactor above the P-8 setpoint. The DEH low pressure trip at 900 psig serves to close the turbine control and stcp valves which in turn would trip the reactor through the turbine stop valve closure switch at 1% open.

EVALUATION The existing Technical Specification Table 2.2-1, Reactor Trip System Instrumen-tation Trip Setpoints, itea 12.A., specifies a DEH pressure trip setpoint for the turbine control and stop valves. Since the Deli system low pressure trip does not directly feed the reactor trip circuit, the setpoint specified should accurately reflect the operation of the control oil pressure switches which directly initiate the reactor trip as described above.

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We agree with the licensco's conclusion that the revised turbine trip low systeu gga.

pressure trip correctly reflects the reactor trip function and does not result in oo any adverse safety i@lications.

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S:c ENVIRONMENTAL CONSIDERATION 88 Q

We have determined that the anendment does not authorize a change in effluent types o

of total anounts nor an increase in power level and will not result in any signifi-08 cant environmental inpact. Having nade this determination, we have further con-ma.1 cluded that the auendment involves an action which is insignificant from the stand-point of environmental impact and, pursuant to 10 CFR Section 51.5(d)(4), that an environrental i; pact statement or negative declaration ar.d environmental impact

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. CONCLUSIO!!

We have concluded, based on the considerations discussed above, that: (1) because the amendoent does not involve a significant increase in the probability or con-seqt.ences of accidents previously considered and does not involve a significant decr rase in a safety niargin, the amendment does not invcive a significant hazards consideration, (2) there is reasonable assurance that the healtn and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Comission's regulations and the issuPce of this amendnent will not be inimical to the comon defense and security or to the health and safety of the public.

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