ML19323B659
| ML19323B659 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 04/25/1980 |
| From: | Ippolito T Office of Nuclear Reactor Regulation |
| To: | Mayer L NORTHERN STATES POWER CO. |
| References | |
| NUDOCS 8005140038 | |
| Download: ML19323B659 (3) | |
Text
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UNITED STATES g,
NUCLEAR REGULATORY COMMISSION i$
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APRIL 2, 5 1990 Docket No. 50-263
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Mr. L. O. Mayer, Manager Nuclear Support Services Northern States Power Company 414 Nicollet Mall - 8th Floor Minneapolis, Minnesota 55401
Dear Mr. Mayer:
SUBJECT:
EFFECT OF A DC POWER SUPPLY FAILURE ON ECCS 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 sing'e failure condition for some j
breaks. The enclosed letter report was sut titted 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 te@eratures associated with various postulated DC power j
supply failure (ECCS egipment availability) cases to the peak cladding temperatures for a HPCI (small break) failure and LPCI injection valve (large break) failure cases. Since the study was based on plant design information which may. have been incoglete or out-of-date, some uncer-tainty exists whether the worse ECCS system availability combinations have been identified -for your operating BWRs.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 Monticello Nuclear Generating Plant, 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 availaHe for large and small (1) recircu-lation loop discharge breaks, and (2) recirculation loop suction breaks.
The listing of equipment available sheuld take into account not only DC power supply failure, but also loss of equipment die to water spillage.
Please provide a schedule for your response within 30 days of the receipt of this letter.
Mr. L. O. Mayer APRIL 2 5 1980 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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s Thoma Ippolito, Chief Operating Reactors Branch #3 Division of Operating Reactors
Enclosure:
General Electric Company lettery (R. E. Engel) to USNRC (P. S..i Check), "DC Power Source Failure for BWR/3 and 4," dated November 1, 1978.
cc w/ enclosure:
See next page O
O
Mr. L. O. Mayer Northern States Power Company APRIL 2 5 580 cc:
Gerald Charnoff, Esquire Mr. Steve Gadler Sahw, Pittman, Potts and 2120 Carter Avenue Trowbridge St. Paul, Minnesota 55108 1800 M Street, N. W.
Washington, D. C.
20036 Arthur Renquist, Esquire Vice President - Law Northern States Power Company 414 Nicollet Mall Minneapolis, Minnesota 55401 Mr. L. R. Eliason Plant Phnager Monticello Nuclear Generating Plant Northern States Power Company Monticello, Minnesota 55362 Russell J. Hatling, Chairman Minnesota Environmental Control Citizens Association (MECCA)
Energy Task Force 144 Melbeurne Avenue, S. E.
Minneapolis, Minnesota 55414 Ms. Terry Hoffman Executive Director Minnesota Pollution Control Agency 1935 W. County Road B2 Roseville, Minnesota 55110 i
The Environmental Conservation Library Minneapolis Public Library 300 Nicollet Mall Minneapolis, Minnesota 55401
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