ML20235T833
| ML20235T833 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 09/30/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20235T831 | List: |
| References | |
| NUDOCS 8710130241 | |
| Download: ML20235T833 (2) | |
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i SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION
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SUPPORTING AMENDMENT NO. 36 TO FACILITY OPERATING LICENSE il0. NPF-29
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MISSISSIPPI POWER & LIGHT COMPANY SYSTEM ENERGY RESOURCES, INC.
i SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION 1
GRAND GULF NUCLEAR STATION, UNIT 1
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DOCKET NO. 50-416 INTRODUCTION By letter dated July 6, 1987 System Energy Resources', Inc. (the licensee) requested an amendment to Facility Operating License No. NPF-29 for the Grand Gulf Nuclear Station, Unit 1.
The licensee requested three changes to the Technical Specifications:
(1) an increase in the setpoint for the pump relief valve in a surveillance requirement for the standby liquid control system (SLCS);
(2) revision of certain action statements to allow entry into operational con-ditions, provided the requirements in the action statements are met; and (3) deletion of the requirements for certain isolation valves and associated instrumentation to be operable in refueling shutdowns. This evaluation addresses the requested increase in the setpoint for the pump relief valve in l
the SLCS.
The other two requested changes will be addressed separately, By letter dated September 14, 1987, the licensee proposed further changes to the surveillance requirements of the SLCS. These proposed changes clarified the requirements for running the surveillance tests, but did not change the requested increase in tne setpoint for the SLCS pump relief vr,1ve. Because no substantive changes were requested in the September 14, 1987 letter, the' application was not renoticed.
EVALUATION The Technical Specifications (TSs) for the SLCS require that the SLCS pumps-I be tested quarterly to demonstrate the capability of developing a minimum flew.
of 41.2 gpm at a pressure of greater than or equal to 1220 psig.
This surveil-lance requirement has been difficult to meet because the SLCS pump relief valve lifts occasionally during the running of the test. The SLCS pumps are j
piston-type, positive displacement pumps. Each time the piston stmkes, the discharge pressure oscillates. At the specified minimum flow discharge pressure of 1220 psig, each piston stroke chuses the discharge pressure to rise approxi-mately 100 psi, bringing the total discharge pressure to about 1320 psig.
Sur-ve111ance Requirement 4.1.5.d.2 currently requires the pump relief valve setpoint to be less than or equal to 1386 psig. The relief valves are ASME Class 2 valves and, as such, have a 3% tolerance in the set pressure, in accordance with the ASME Code.
Since there is a 3% tolerance on the relief valve opening, a very-1 8710130241 870930 1
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small margin exists between the peak system pressure and the relief valve mini-mum opening pressure during the pump surveillance tests.
Because the system test pressure is difficult to control in the test. configuration.. the relief valve sometimes opens.
The SLCS piping design pressure is 1400 psig at the pump discharget This:
piping is ASME Class 2 piping. The ASME Code,Section III, pemits the over-protection relief valve to be set at the design pressure and requires the relief valve to open within_3% of the setpoint.
In order to minimize the potential for opening the relief valve during the running of the test, it is proposed that the relief valve setpoint be increased to 1400 psig and that Sur-ve111ance Requirement 4.1.5.d.2 be changed to verify that the relief valve opens within 3% of the setpoint pressure.
The NRC staff has reviewed the proposed increase in the SLCS pump relief valve s6tpoint. The proposed setpoint_ of 1400 psig is in accordance with the ASME Code requirements and therefore the relief valve would continue to protect the SLCS discharge piping.
The staff concludes that the proposed increase in the.setpoint would improve the capability to perform surveillance tests of the SLCS without impairing system integrity.
The increased setpoint meets the ASME Code requirements for system integrity and is therefore acceptable.
ENVIRONMENTAL CONSIDERATION This amendment involves a change to a requirement with respect to the l
installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance requirements.
The staff has determined that the amendment involves 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 individual or cumulative occupational radiation. exposure.
The Consnission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public conenent on such finding.
Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forthin10CFR51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
CONCLUSION The staff has concluded, based on the considerations discussed above, that:
I (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Connission's regulations and the issuance of this amendment will not be inimical to the conunon defense and the security nor to'the health and safety of the public.
Dated: September 30, 1987 q
Principal Contributors:
E. J. Sullivan, Jr., Mechanical Engineering Branch.. DEST i
L. L. Kintner, Project Directorate II-2, DPR-I/II 1
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