ML20135E589

Requests Review of Encl Questions & Confirmation of Continued Assistance in Resolution of Generic Issue 77 Re Flooding of Safety Equipment Compartments by Backflow Through Floor Drains

ML20135E589
Person / Time
Site:	Rancho Seco
Issue date:	09/06/1985
From:	Stolz J Office of Nuclear Reactor Regulation
To:	Reinaldo Rodriguez SACRAMENTO MUNICIPAL UTILITY DISTRICT
References
NUDOCS 8509160454
Download: ML20135E589 (3)

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. September 6,1985 Docket No. 50-312 DISTRIBUTION (BecketFileT ACRS-10 NRC PDR' "

• Ringram L PDR SMiner Mr. Ronald J. Rodriguez ORB #4 Rdg Gray File Assistant General Manager, Nuclear HThompson EBrach Sacramento Municipal Utility District OELD H0rnstein 6201 S Street EJordan WPaulson P. O. Box 15830 BGrimes GEdison Sacramento, California 95813 JPartlow

Dear Mr. Rodriguez:

The NRC staff is in the process of developing its policy regarding " flooding of safety equipment compartments by backflow through floor drains" which we have designated as Generic Issue 77. We are contacting several utilities to seek their voluntary assistance by responding to the enclosed questions. The possibility of Sacramento Municipal Utility District's participation in this effort was discussed with Mr. J. Delezenski of your staff and at that time he indicated a preliminary agreement 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.

The reporting and/or recording keeping requirements contained in this letter affect fewer than ten respondents, therefore OMB clearance is not required under P.L.96-511.

Sincerely,

• usto u m ,stm:na sg JCums. s g o John F. Stolz, Chief Operating Reactors Branch #4 Division of Licensing

Enclosure:

As Stated cc w/ enclosure:

See next page 8509160454 05090632 DR ADOCK 0 0%"S5 y/3/85 EW p/pB5

Mr. R. J. Rodriguez Rancho Seco Nuclear Generating Sacramento Municipal Utility District Station cc:

Mr. David S. Kaplan, Secretary Sacramento County and General Counsel Board of Supervisors Sacramento Municipal Utility 827 7th Street, Room 424 District Sacramento, California 95814 6201 S Street P. O. Box 15830 Ms. Helen Hubbard Sacramento, California 95813 P. O. Box 63 Sunol, California 94586 Thomas Baxter, Esq.

Shaw, Pittman, Potts & Trowbridge 1800 M Street, N.W.

Washington, D.C. 20036 Mr. Robert B. Borsum Babcock & Wilcox Nuclear Power Generation Division Suite 220, 7910 Woodmont Avenue Bethesda, Maryland 20814 Resident Inspector / Rancho Seco c/o U. S. N. R. C.

14410 Twin Cities Road Herald, California 95638 Regional Administrator, Region V U.S. Nuclear Regulatory Commission 1450 Maria Lane, Suite 210 Walnut Creek, California 94596 Director Energy Facilities Siting Division Energy Resources Conservation &

Development Commission 1516 - 9th Street Sacramento, California 95814 Mr. Joseph 0. Ward, Chief Radiological Health Branch State Department of Health Services 714 P Street, Office Building #8 Sacramento, California 95814 l

Enclosure RANCHO SECO NUCLEAR GENERATING STATION DOCKET NO. 50-312 .

REQUEST FOR INFORMATION GENERIC ISSUE 77 1.

Provide a' detailed discussion of the equipment and floor drainge system (s) which serve safety-related equipment or compartments containing safety-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) and flooding due to tank failures and pipe breaks including 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 floca 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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