ML19208C775

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Responds to NRC 790626 Ltr Re Violations Noted in IE Insp Rept 50-395/79-17.Corrective Actions:Site Contractor Will Submit Design Drawings for Fire Protection Equipment & Appurtenances Which Are to Be Installed
ML19208C775
Person / Time
Site: Summer South Carolina Electric & Gas Company icon.png
Issue date: 07/18/1979
From: Jerrica Johnson
SOUTH CAROLINA ELECTRIC & GAS CO.
To: James O'Reilly
NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML17146B285 List:
References
NUDOCS 7909270436
Download: ML19208C775 (3)


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  • SOUTH 6 ROUNLELECTRIC a gas COMPANY CeLuMs A.Sout.- CAnouuA 29288 M.C.JoMuson
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  • July 18, 1979 United Ststes Nuclear Regulatory C m:11ssion ATTN: Mr. James P. O'Reilly Director Marietta Building, 31st Floor 101 Marietta Street, NW Atlanta, Georgia 30303

Subject:

V. C. Summer Nuclear Station Unit #1 Response to NRC Audit Report 50-395/79-17 dated 6/26/79 Gentlemen: In response to the above captioned report, we have reviewed the infor-

        =ation found there-in and find it contains no pror -ietary information.                In addition, we have evaluated the circumstances relcring to the ites identified as 79-17-01 in the captioned report, which dealt 5 th a notice of deviation in relation to our fire pump installation. Examin.: tion of the background of this determination provides the following infor-.ation:
1. Cause The fire pumps were designed and installed in acccrdance with NFPA-20 with the two exceptions noted in the Notice of Deviation. The pressure sensing lines were fabricated by Site Construction rather than the vendor and, therefore, no drawings detailing the:se lines had been sent to GAI for review and approval.

The e'.ec:ric motor driven fire pump is powered from a 430 volt load . enter at the circulating water intake. The load center is powered by a 1000/1333 KVA transformer. There are 8 circuit breakers on the load center plus a main breaker. The circuit breaker for the fire pump does net feed any other loads. The fire pump is coittrolled by a UL approved controller that also contains a circuit breaker. It is our intention to coordinate f u n :o.,pj h pv nq 4 9 0 9 2 7 C/f S 6 gJ a u ~ L a , ; h 1049~ 316

Mr. James P. O'Reilly Page 2 July 18, 1979 the breakers involved so that the breaker on the controller would be the first to trip in case of a fault in the motor. The fire pump motor is rated 345 amps full load and 2243 amps locked rotor. The fire pump breaker in the 480V load ce-ter will be set at its maxi-mum setting, which is 660 amps long time delay trip, 3200 amps short time delay trip, and 4800 amps instantaneous trip. The breaker in the controller will be set as close to this as possible, but slightly lower in order to coordinate. The load center main breaker and other breakers in the system supply are set successively higher to provide overall system coordination. We consider that setting the long time delay trip at locked rotor current (2243 amps), as required by NFPA-20, would be impractical as this would exceed the transformer rating considerably. Both the short time delay and the instantaneous setting will considerably exceed the locked rotor current of the motor. We consider that these settings will ensure pump starting, if at all possible, and still protect the switchgear. It is noted that if the breaker were set at 2243 amps long time delay, tne 480 volt load center and transformer would probably be destroyed, possibly creating another fire.

2. Immediate Corrective Steps Taken and Results The pressure sensing lines will be replaced by lines that meet the requirements of NFPA-20. The FSAR and the Fire Protection Evaluation / Fire Hazard Analysis will be amended in accordan a with this position.
3. Corrective Steps Taken to Avoid Future Noncompliance In the future, Site Construction will be required to submit design drawings for fire protection equipment and appurtenances which is to be installed by Site Constrdction and is not included within any vendor's scopo, to the appropriate engineering organization for review and approval consistent with relevant FSAR commitments. In addition, it will be confirmed that the power supply for any additional motor driven fire pump that might be added in the future, complies with the positien set forth herein.

1049 317

?,, Nr. James P. O'Reilly Pane 3 Julf 18, 1979

4. Full Compliance Date The actions indicated above will be completed by October 15, 1979.
             'Je trust that you will find our actions to resolve this item appropriate and satisfactory. Please feel free to contact us if we can provide additional information in relation to this item or the subject report.

Very truly yours, A/ M U DAN /MCJ/jls cc: C. J. Fritz G. C. Meetze 1049 318}}