ML20135H369
| ML20135H369 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 09/09/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20135H367 | List: |
| References | |
| TAC-56985, NUDOCS 8509230118 | |
| Download: ML20135H369 (2) | |
Text
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UNITED STATrS NUCLEAR REGULATORY CCNWISSION o
y WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT N0. 55 TO FACIIIT1 OPERATING LICENSE NO. NPF-5 GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA EDWIN I. HATCH NUCLEAR PLANT, UNIT NO. 2 DOCKET NO. 50-366 Evaluation By letter dated February 15, 1985, and supplemented by letter dated May 14, J985. Georgia Power Company (GPC or the licensee) requested modifications of the Technical Specifications of the hydraulic control unit (HCU) to change the pressure alann setpoint from 955 15 psig to t940 psig and the automatic depressurization system (ADS) timer relay nomenclature from (2B21-K5 A,B) to (2821-K752 A,B).
The purpose of the HCU pressure alarms in the control room is to warn of a decreasing accumulator pressure condition which could result in insufficient stored energy in the accumulator to meet scram time requirements at low reactor pressure conditions. At nonnal operating conditions, reactor pressure alone is sufficient to insert a control rod.
The specification currently requires that the HCU pressure detectors be i
calibrated to-alarm at 955 i 15 psig. Operating experience has shown that, due to temperature-induced instrument drift, this narrow tolerance cannot be met reasonably.
It results in recurring failures of HCU to meet the operability requirements of the Technical Specifications. To eliminate this problem, the licensee has proposed to change the pressure alarm setpoint to 1940 psig. The lower limit of the tolerance band is the important limit which l
1s preserved by the channel calibration.
The pressure alann limit of 940 psig will be unaffected by this change.
The ADS timer relay number is a nomenclature change and does not reflect any change in plant operation or setpoints.
We find the proposed changes to the TSs acceptable.
l 8509230118 850909 PDR ADOCK 05000366 P
l
. Environmental Consideration This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
We have 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 Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(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 the amendment.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) there is reasonable ~ assurance that the taalth and safety of the will not be endangered by operation in the proposed manner, and (2) public such activities will be conducted in compliance with the Commission's regulations, and the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Dated: September 9,1985 Principal Contributor:
K. Desai e
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