ML19209A166
| ML19209A166 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 09/06/1979 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19209A165 | List: |
| References | |
| NUDOCS 7910030045 | |
| Download: ML19209A166 (2) | |
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- ( 3 g NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 5'\\'
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%.x.- p SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NOS. 52 AND 51 TO FACILITY OPERATING LICENSE N05. DPR-32 AND DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-280 AND 50-281 Introduction By letter dated August 8,1979, Virginia Electric and Power Company (the licensee) proposed modifications to the safety injection actuation.,ystem logic for Surry Power Station Unit Nos. I and 2 in response w Item 3 of IE Bulletin 79-06A dated April 14, 1979.
These modifications will require two out of three channels of low pressurizer pressure for actuation.
Discussion and Evaluation Since the date of licensing until the issuance of IE Bulletin 79-06A, safety injection was initiated, in addition to other parameters, based on coincident trip of one-of-three matched pairs of low pressurizer level and low pressurizer pressure trips.
Item 3 of IE Bulletin 79-06A directed all facilities using pressurizer water level coincident with pressurizer pressure for automatic initiating of safety injection to trip the low pressurizer level setpoint bistables so that when pressurizer pressure reaches the low setpoint, safety injection would be initiated regardless of the pressurizer level.
Because of the concern that this action has resulted in placing Surry Units 1 and 2 in a condition (one-out-of-three trip) which is more susceptible to spurious actuation of the safety injection system, the licensee has proposed modifications and related Technical Specification chanqes to alleviate this situation.
The pr oposed modifications to the safety injection actuation system consist of removing the pressurizer level signal from each of the pressurizer lever pressure channel tripc and converting the system to a two-out-of-three logic based on the pressurizer low pressure trips.
The instrumentation logic receives pressurizer pressure signals from three pressure transnitters and ir.it ;ates a safety injecticn actuation when tuo of the three signals reach the lcw oressure set-ooint of 1,700 psig. These nodifications do not involve a chance in the setpoint.
These nodifications will satisfy the requirerents of IEEE 279-1971, and other applicable standards.
The ncdi'ications eill be implemented during the current outage on Unit 2 and at the next cold shutdown for Unit 1.
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. Based c nur review of the licensee's submittal, we conclude that the modi'ications to the safety injection actuation system logic satisfy the requirements of IEEE 279-1971 and that the changes in Technical Specifications are correct, and therefore, are acceptable.
Environmental Consideration We have determined that the amendments do not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact.
Having made this determination, we have further concluded that the amendments involve an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 551.5(d)(a), that an environmental impact statement or negative declaration and environ-mental impact appraisal need nrt be prepared in connection with the issuance of these amendments.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the amendments do not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the amendments do not involve a significant hazards consideration, (2) theru is reasonable assurance that the health and safety of the public will not be endangerea by operation in the proposed manner, and (3) such activities will ue conducted in compliance with the Commission'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.
Date: September 6,1979 1084 263