ML20034C626
| ML20034C626 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 05/01/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20034C625 | List: |
| References | |
| NUDOCS 9005040233 | |
| Download: ML20034C626 (2) | |
Text
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.t waswiwoTow. o. c. 20sss (-.....,/ SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATI RELATED TO AMEN 0 MENT NO.141 TO FACILITY OPERATING LICENSE ' AND AMENCMENT NO.139 TO FACILITY OPERATING LICENSE'NO. DPR-37 VIRGTHIA ELECTRIC AND POWER COMPANY SURRY POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-280 AND 50-281 1.0 lHTRODUCTION' pursuant to 10 CFR 50.90, Virginia Electric and Power Company (VEPCO) Surry Power Station, Units 1 and 2. proposed to-amend Facility Operating Licens j By letter dated December 29. 1989,- l VEPC0 proposed a Technical Specification change to delineate.the surveil-lance requirements for the emergency diesel generatorLload sequencing-i modification which was completed in 1989. The original: design of the emergency power system considered a loss-of-coolant accident (LOCA)-with a simultaneousloss-of-offsitepower-(LOOPFastheworst-caseloading 1 condition for the emergency diesel generotors.- However, VEPCO's re-analysis indicated the potential tor losing both emergency diesel generators-in:the 1 event of a LOOP occurring at-least several minutes subsequent to a LOCA if j all:of the accident loads were simultaneously loaded onto the diesels. 1 Based on this analysis; VEPC0 modified the logic schemes to shed and after a LOCA. sequence the emergency loads onto the diesel generator if a LOOP occurred 2.0 EVALUATION a VEPC0 proposed a change to Technical Specification Section 4.6 to perio'd-ically test the sequence and' load;shed feature for a' simulated LOOP condition' subsequent to a LOCA. the safe' shutdown loads in the prescribed sequence.Each diesel generator is desig The reconnection of 1 all the loads at the same time could result in'an overload condition, causing the trip of the respective diesel generator. Therefore, it-is i necessary to shed all the connected safe shutdown inads and resequence them onto the diesel generator if a LOOP condition occurs subsequent-'to a i LOCA. The proposed testing will assure the ability of the emergency 1 ' LOOP subsequent to a design basis accident, by sequencing- { the energency buses in acceptable loading blocks. j a We have reviewed the licensee's submittal and have concluded that the proposed change to-include the surveillance requirements.assnciated with-Technical Specification 4.6 will assure the ability of the emergency-diesel generators to' power the necessary shutdown loads following a L?0P subsequent to a LOCA and are, therefore, acceptable. "a ~ i ;O P -l 0
1 -2 .. i. D': _4 0 ENVIRONMENTAL CONSIDERATION: q These amendments involve a change.in a requirement with respect to the installation or use of a facility component ~ located within the restricted areas as defined in '10'CFR Part 20 and a change. to a-surveillance require-- ment. The staff has determined that these amendmentssinvolve no significant-increase in the amounts, and-no-sign;ficant change in the, types, of any effluents that may be released ^offsite, and that there is no significant q increase in individual or cumulative occupational 1 radiation exposure. >The: ~ Commission has previously_ issued-a proposed finding that'these amendments involve no significant: hazards consideration and'there has been'no public? 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 environ-mental assessment need be prepared in' connection with the issuance of these amendments. '4. 0 CONCLUSION d We have concluded, based'on:the considerationsidiscussed above, that:1 I (1)there.is_reasonableassurancethatthehealthand.safet o will.not be endangered by operation in the proposed manner,y of the public-and (2) such' activities'will be~ 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 Dated: May 1, 1990. princiaal Contributors: l N. Trelan B. Buckley 1 ,i -k j 1 I r s F-i i-
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