ML20148H210
| ML20148H210 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 01/21/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20148H168 | List: |
| References | |
| TAC-57242, TAC-63256, NUDOCS 8801270162 | |
| Download: ML20148H210 (2) | |
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UNITED STATES 8
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NUCLEAR REGULATORY COMMISSION g
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_ SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.14 TO FACILITY OPERATING LICENSE NO. NPF-37, AMENDMENT N0.14 TO FACILITY OPERATING LICENSE NO. NPF-66, AMENDMENT NO. 4,TO FACILITY OPERATING LICENSE NO. NPF-72 AND AMENDMENT N0. 4 TO FACILITY OPERATING LICENSE NO. NPF-75 COMMONWEALTH,EDIS0N COMPANY BYRON STATION, UNITS 1 AND 2 BRAIDWOOD STATION, UNITS 1 AND 2 DOCKET NOS. STN 50-454, STh 50-455, ETN 50-456, AND STN 50-457 TAC NOS. 57242, 63256 INTRODUCTION In May 1984 Comonwealth Edison Company (the licensee) submitted its Limiting Conditions for Operation Relaxation Program (LCORP), which proposed to increase the allowable outage times (A0T) in the Technical Specifications from 72 nours to 7 days for several systems and subsystems. The submittal included a Probabilistic Risk Assessment (PRA) done to evaluate the change in risk to the public with the increased A0T. NRC obtained assistance from Brookhaven National Laboratory in reviewing the PRA.
By application dated September 29, 1987 the licensee requested amendments to the Technical Specifi-cations for Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2.
The proposed changes increase the A0Ts to 7 days for some, but not all, of the systems and subsystems originally proposed in the licensee's LCORP.
EVALUATION On December 3 and December 6, 1985, the NRC and BNL met with licensee to discuss the review of LCORP. Details of the meeting are oacumented in the January 24, 1986 Meeting Sumary.
The major issue discussed at the meeting was that BNL cstimated the core melt freguency for Byron 1 (the only uni-operation at that time) to be about 10' / year. This issue was resolver in interim basis by the comitments mado in the licensee's December 6, 19eo.etter.
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At the meeting, BNL also presented the results of its review concerning the licensee's request to increase several A0Ts. BNL indicated that the increase in core melt frequency when increasing the A0T from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 7 days is negligible for the following six systems:
containment heat removal system (containment spray pumps and fan coolers). Emergency Core Cooling Systems
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.(charging pumps Safety Injection pumps and Residual Heat Removal pumps),
and component cooling.
For the auxiliary feedwater pumps,_ the effect of the increased A0T is slightly greater, and for the diesel generators and the
-essential service water pumps the effect is greater still.
Subsequent to the meeting, the results of BNL's review were published in NUREG/CR-4404, BNL-NUREG-51930 "Analysis.of Allowed Outage Times at the Byron Generating Station," June 1986.
The staff, in a January 15, 1986 memorandum from Themis P. Speis to Hugh L. Thompson, supported BNL's conclusion that the increased A0T should be pennitted for the aforementioned six systems and should be denied for the auxiliary'feeowater pumps, diesel generators and essential service water pumps.
The licensee has also evaluated the differences between the Byron and Braidwood plant designs and detennineo that the differences are insignificant in thef contribution to the core melt modeling. Therefore, the licensee-concluded that the conclusions of the Byron study apply to the Braidwood Units. The staff agrees.
The September 29, 1987 application requested increased A0T for only those six systems that were four.d to be acceptable by BNL and the staff. Therefore, we find the proposed Technical Specifications acceptable.
ENVIRONMENTAL CONSIDERATION These amendments involve a change in the installation or use of the facilities' components located within the restricted areas as defined in 10 CFR 20.
The staff has determined that these amendments involve 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 Comission l
has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public coment on i
such finding. Accordingly, these amendments meet the eligibility criteria j
forcategoricalexclusionsetforthin10CFRSec51.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assess-ment need be prepared in connection with the issuance of these amendments.
CONCLUSION We have concluded, based on the considerations discussed above, that:
(1)there is reasonable assurance that the health and safety of the public vili not be endangered by operation in the proposed manner, and (?) such activities will be conducted in compliance with the Comission'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.
Principal Contributor:
L. Olshan Dated: January 21, 1988
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