ML20235E996

Requests Review of Facilities to Determine Whether Failure of Equipment That Does Not Meet Criteria of Class I Seismic Const Could Cause Flooding Sufficient to Adversely Effect Performance of ESFs

ML20235E996
Person / Time
Site:	Monticello, 05000000
Issue date:	08/03/1972
From:	Skovholt D US ATOMIC ENERGY COMMISSION (AEC)
To:	Dienhart A NORTHERN STATES POWER CO.
Shared Package
ML20235B311	List: IA-87-111, Submits Rept on Plant,As Discussed in ACRS 150th Meeting on 721012-14.Listed Items Can Be Resolved During Const & Facility Can Be Constructed W/Reasonable Assurance for Operation W/O Undue Risk to Public Safety IR 05000254/1972009 IR 05000358/1972003 IR 05000358/1973001 IR 05000358/1973002 IR 05000358/1973003 IR 05000358/1973005 IR 05000358/1973006 IR 05000358/1973007 IR 05000358/1974001 IR 05000358/1974002 IR 05000358/1974003 IR 05000358/1975004 ML20235B308 ML20235B364 ML20235B401 ML20235B405 ML20235B424 ML20235B456 ML20235B461 ML20235B465 ML20235B477 ML20235B488 ML20235B507 ML20235B552 ML20235B582 ML20235B585 ML20235B588 ML20235B605 ML20235B618 ML20235B623 ML20235B649 ML20235B656 ML20235B662 ML20235B670 ML20235B679 ML20235B683 ML20235B687 ML20235B702 ML20235B708 ML20235B713 ML20235B714 ML20235B718 ML20235B720 ML20235B730 ML20235B734 ML20235B748 ML20235B754 ML20235B762 ML20235B764 ... further results
References
FOIA-87-111 NUDOCS 8709280368
Download: ML20235E996 (2)

Text

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, YC.,)C(,Jc-UNITED STATES ATOMIC ENERGY COMMISSION l *I '

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WASHINGTON. D.C. 20545

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August 3, 1972 Docket No. 50-263 -

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Northern States Power Company ATTN: Mr. Arthur V. Dienhart Vice President of Engineering 414 Nicollet Hall Minneapolis, Minnesota 55401 -

Gentlemen:

FLOODING OF CRITICAL EQUIPMENT A failure of an expansion bellows in the circulating water line which serves the main condenser recently occurred at Quad-Cities Unit 1. The resultant flooding caused degradation of some of the engineered safety features. Interim corrective action has been taken and more permanent corrective measures are planned at Quad-Cities 1 and 2 to prevent recurrence. A copy of the abnormal occurrence report filed by Commonwealth Edison for this event is enclosed.

You are requested to review your facilities to determine (1) whether f ailure of any equipment which does not meet the criteria of Class I seismic construction, particularly the circulating water system, could cause flooding sufficient to adversely affect the performance of engineered safety systems, and (2) whether failure of any equipment could cause flooding such that common mode failure of redundant safety related equipment would result. The integrity of barriers to protect critical equipment from flood waters should be assumed only when the barrier meets the seismic requirements for Class I structures. If your review determines that engineered safety features could be so affected, provide your plans and schedule for corrective action together with the justifi-cation for continued operation of your facility' pending completion of the corrective action. ' '

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Northern States Power Company August 3, 1972 The results of your review are requested within sixty days. This infor-mation should be provided with one signed original and thirty-nine additional copies.

Sincerely, W

Donald J. y olt

~ Assist c Director for i Operating Reactors Directorate of Licensing

Enclosure:

CE ltr dtd 6/17/75 (htt b Ad 40-27%

cc: Gerald Charnoff.

Shaw, Pittman, Potts, Trowbridge & Madden 910 - 17th Street, N. W.

Washington, D. C. 20006

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