ML19323B665
| ML19323B665 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 04/25/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Counsil W NORTHEAST NUCLEAR ENERGY CO. |
| References | |
| TASK-06-07.C2, TASK-6-7.C2, TASK-RR NUDOCS 8005140045 | |
| Download: ML19323B665 (3) | |
Text
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UNITED STATES NUCLEAR REGULATORY COMMISSION E
WASmNCTON, D. C. 20555 j
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I APRIL 2 5 1980 Docket No. 50-245 l
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Mr. W. G. Counsil, Vice President Nuclear Engineering and Operations Northeast Nuclear Energy Conpany P. O. Box 270 Hartford, Connecticut 06101 Dear Mr. Counsf1
SUBJECT:
EFFECT OF A DC POWER SUPPLY FAILURE ON CCCS PERFORMANCE It has generally been recognized that the loss of a direct current (DC) power supply could disable several emergency core cooling system components and thereby could result in a limiting single failure condition for some breaks. The enclosed letter report was submitted to the NRC staff by the General Electric Company to provide a definitive, generic, reference analysis of the effects of DC power supply failures on ECCS conformance calculations. The NRC staff is reviewing the analysis which compares the peak cladding tenperatures associated with various postulated DC power supply failure (ECCS egipment availability) cases to the peak cladding tenperatures for a HPCI (small break) failure and LPCI injection valve (large break) failure cases. Since the study was based on plant design infor. nation which may have been inconplete or out-of-date, some uncer-tainty exists whether the worse ECCS system availability combinations have been identified for your operating BWRs. Accordingly, in order that we may have an adequate level of assurance that the systems com-binations assumed in the generic analysis are conservative for Millstone Nuclear Power Station, Unit No.1, we request that you confirm the conclusion of the reference study regarding the minimum ECCS equipment availability with a DC power supply failure.
Include in your response a list of the ECCS equipment that would be available for large and small (1) recircula-tion loop discharge breaks, and (2) recirculation loop suction breaks.
The listing of equipment available should take into account not only DC pcwer supply failure, but also loss of equipment due to water spillage.
Please provide a schedule for your response within 30 days of the receipt of this letter.
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Mr. W. G. Counsil APRIL 2 5 EO This request for generic information was approved by GA0 under clearance,.,-
number B-180225(579018); this clearance expires October 31, 1980.
Sincerely.
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A. Ippolito, Chief Operating Reactors Branch #3 Division of Operating Reactors
Enclosure:
1 General Electric Company letter (R. E. Engel) to USNRC (P. 3.
Check), "DC Power Source Failure for BWR/3 and 4," dated November 1, 1978.
cc w/ enclosure:
See next page
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i APRIL 9 5 E00 Mr. W. G. Counsil
-3 l
CC William H. Cuddy, Esquire Connecticut Energy Agency '
Day, Berry & Howard ATTN: Assistant Director Counselors at Law Research and Policy One Constitution Plaza
. Development Hartford, Connecticut 06133 Department of Planning and Energy' Policy Anthony Z. Roisman 20 Grand Street Natural Resources Defense Council Hartford, Connecticut 06106 917 15th Street, N. W.
Washington, D. C.
20005 Director, Technical Assessment Division No.*theast Nuclear Energy Company Office of Radiation Programs ATTN.: Superintendent (AW-459)
Millstone Plant U. S. Environmental Protection P. O. Box 128 Agency Waterford, Connecticut 06385 Crystal Mall #2 Arlington, Virginia 20460 Mr. James R. Himmelwright Northeast Utilities Service Co pany U. S. Environmental Protection P. O. Box 270 Agency Hartford, Connecticut 06131 Region I Office ATTN:
EIS COORDINATOR JFK Federal Building Resident Inspector c/o U. S. NRC Boston, Massachusetts 02203 P. O. Box Drawer KK Niantic, Connecticut 06357 Waterford Public Library Rope Ferry Road, Route 155 Waterford, Connecticut 06385 First Selectman of the Town of Waterford Hall of Records 200 Boston Post Road Waterford, Connecticut 06385
.).
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