ML20058B061
| ML20058B061 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 10/22/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20058B046 | List: |
| References | |
| NUDOCS 9010290375 | |
| Download: ML20058B061 (2) | |
Text
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SAFETY EVALVATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTillG AMENDMENT 110. 131 TO FACILITY OP.RA11tG LICENSE NO. DPR-35 BOSTON EDISON COMPAN\\
PILGRIM NUCLEAR POWER STA"10N i
DOCKET NO. 50-293 INTRODUCTION By letter dated Decembcr 11, 1989, the Boston Edison Company (the licensee) for Pilgrim submitted a proposed change to Technical $pecification (TS)
Section 3/4.5.A.1.d. Core Spray Pump Flow Rate Testing. Pilgrim's current core spray pump surveillance test acceptance criteria is a flow rate of at least 3600 gpm with a pump discharge pressure greater than 260 psig. This criterion is, and has always been, very close to the limit of pump capability.
As the core spray pumas continue to age normally, small variations in pump performance, within t1e tight tolerance, may result in a core spray pump failing to deliver a flow rate of 3600 gpm, resulting in Pilgrim entering a LimitingConditionofOperation(LCO). To reduce the potential for unnecessarily entering an LCO, the licensee has proposed a reduction of 300 gpm in the flow limit based on a revised, less conservative LOCA analysis.
EVALUATION The licensee has proposed a TS change to reduce the core spray pump flow rate from its present allowabic value of 3600 gpm to 3300 gpm, less then ten percent reduction. To justify this change, the licensee used a LOCA analysis performed byGE("JustificationofInterimO with Reduced Core Spray Flow Rate.geration of Pilgrim Nuclear Power StationSeptel EAS-65-0989, mittal.
The LOCA analysis performed by GE using SAFE /REFLOOD models per Appendix K to 10CFRPart50}demonstratesthat,foratenpercentdecreaseincorespraythe fuel peak cen flow (3240gpm 45' f.
The calculated PCT for the limiting case (recirculation suction line break with an assumed failure of the LPCI injection valve) assuming a 10 percent reduction in core spray system rated flow (3240 gpm) is 2185'F which is below the 2200*F limit. The local cladding oxidation is 2.7 percent (well below the 17 percent limit) and the core wide cladding oxidation is less than 0.2 percent (wellbelowthe1percentlimit).
The LOCA was reanalyzed utilizing the staff approved GE evaluation models SAFE /REFLOOD CHASTE. Pilgrim would continue to meet the requirements of Appendix K to 10 CFR Part 50.46. Therefore, the proposed reduced core spray flow of 3300 gpm is acceptable based on LOCA considerations. The proposed change requests a minimum flow of 3300 gpm instead of 3240 gpm to reflect the impact of degraded voltage on pump performance. This gives additional margin in the pump test acceptance criteria and hence is acceptable.
9010290375 901022 PDR ADOCK 05000293 P
e PMIRONMENTAI CONSIDERATION This amendment involves a change in a requirement with respect to the installation or use of a facility component located within thi restricted area as defined in 10 CFR Part 20 and/or 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 Commission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in10CFR51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with l
the issuance of this amendment.
CONCLUS10N The Commission made a proposed determination that the amendment involves no significant hazards consideration which was published in the federal Register (55 FR 2432) on January 24, 1990 and consulted with the Commonwealth of Massachusetts, No public comments were received and the Commonwealth of Massachusetts did not have any connents.
The proposed TS changes in Sections 4.5.A.1.d and 3.5.A are acceptable as given in the SER.
The staff has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the will not be endangered by operation in the prososed manner, and (2) public 1
such activities will be conducted in compliance wit 1 the Commission's regulations, and (3) issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
G. Thomas Dated:
October 22, 1990 l
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