ML20134G415
| ML20134G415 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 08/06/1985 |
| From: | Butcher E Office of Nuclear Reactor Regulation |
| To: | Musolf D NORTHERN STATES POWER CO. |
| References | |
| NUDOCS 8508260065 | |
| Download: ML20134G415 (3) | |
Text
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August 6, 1985 DISTRIBUTION:
Docket Nos. 50-282 DUCKETaFILE ACRS +10 and 50-306 ORB #3 Rdg Gray File LOCAL PDR HThompson OELD Mr. D. M. Musolf EJordan Nuclear Support Services Department BGrimes Northern States Power Company JPartlow 414 Nicollet Mall - 8th Floor DCDi Ianni Minneapolis, Minnesota 55401 PMKreutzer
Dear Mr. Musolf:
The NRC staff is in the process of developing a policy regarding " flooding of safety equipment compartments by backflow through floor drains" which we
- have designated as Generic Issue 77. We have been contacting several utilities to seek their voluntary assistance by responding to the enclosed questions. The possibility of Northern States Power Company's voluntary participation in this effort was discussed with you by teleconference on July 26, 1985. At that time, you indicated a willingness to participate.
The purpose of this letter is to request that you review the enclosed questions and confirm your continued willingness to assist us in the resolution of this generic issue.
In order that we might develop our program schedule as soon as possible, please inform us within 30 days of receipt of this letter whether you can support the program and, if so, when you can respond to the enclosed questions.
We would appreciate it if you could schedule your response to the enclosed ques-tions for no later than 120 days from the date of your response to this letter.
4 OMB Clearance is not required for this request since it is being transaittted to fewer than 10 addressees.
Sincerely, f
/
Edward J. Butcher, Acting Chief Operating Reactors Branch #3 Division of Licensing
Enclosure:
As stated cc w/ enclosure:
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Mr. D. M. Musolf Prairie Island Nuclear Generating Plant Northern States Power Company L
Gerald Charnoff, Esq.
Shaw, Pittman, Potts and Trowbridge 1800 M Street, NW Washington, DC 20036 Executive Director Minnesota Pollution Control Agency 1935 W. County Road, B2 Roseville, Minnesota 55113
'Mr.- E. L. Watzl, Plant Manager Prairie Island Nuclear Generating Plant Northern States Power Company Route 2 Welch, Minnesota 55089 Jocelyn F. Olson, Esq.
Special Assistant Attorney General Minnesota Pollution Control Agency 1935 W. County Road, B2 Roseville, Minnesota 55113 U.S. Nuclear Regulatory Commission Resident Inspector's Office Route #2, Box 500A Welch, Minnesota 55089 Regional Administrator USNRC, Region III Office of Executive Director for Operations 799 Roosevelt Road Glen Ellyn, Illinois 60137 Mr. William Miller, Auditor Goodhue County Courthouse Red Wing, Minnesota 55066
REQUEST FOR INFORMATION GENERIC ISSUE 77 I.
Provide a detailed discussion of the equipment and floor drainge system (s) which serve safety-related equipment or compartments containing sefety-related equipment or compartments. Include diagrams as appropriate.
As part of the discussion, describe the features which will prevent back-flow from any area into compartments containing safety-related equipment.
This discussion should include the drainage system and any other compart-ment openings such as doors, unsealed penetrations of grating through which fluid may flow. Sources of fluid to be considered are external flooding (ground water seepage, surface influence from rivers, lakes and rain fall ponding)andfloodingduetotankfailuresandpipebreaksincluding failure of the expansion joints in the circulating water system. The back-
. flowing fluids to be considered are water, steam and hot air. Confirm for those conditions ' identified above and that redundant safety-related equip-ment will not be adversely affected by fluid ingress into the equipment compartments.
' 2.
Describe the design basis for sizing the equipment and floor drainage systems and the means for assuring that they can effectively handle the maximum leakage flow conditions in the specific plant areas of concern housing redundant safety-related equipment.
3.
Indicate any past incidents of drainage system backflow or other concern for failure of redundant safety-related equipment that has arisen or been postulated in the past due to a fluid leak or harsh environment in safety-related equipment areas.
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