ML20077N315

Confirms 830823 Telcon Info Re Exemption Request for Fire Areas 58,59,73 & 74.Train a Safe Shutdown Cable Trays Will Be Wrapped W/Approved 1 H Rated Matl.Util Reviewing Matls for Use as 1 H Fire Barrier

ML20077N315
Person / Time
Site:	Prairie Island
Issue date:	09/02/1983
From:	Musolf D NORTHERN STATES POWER CO.
To:	Office of Nuclear Reactor Regulation
References
TAC-49949, TAC-49950, NUDOCS 8309130020
Download: ML20077N315 (2)

Text

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r Northem States Power Company di4 Ncollet Mail Minneapolis Minnesota 55401 Telephone (612) 330-5500 September 2,1983 Director Office of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRAIRIE ISLAND IUCLEAR GENERATING PLAtTr Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Supplementary Information to Exemption Request for

- Fire Areas 58, 59, 73 and 74 Reference (A) Letter from D M Musolf to NRR dated June 30, 1982,

" Fire Protection Safe Shutdown Analysis and Compliance with Section III.G. of 10CFR50, Appendix R, Including Request for Relief."

(B) Letter from D M Musolf to NRR dated March 11, 1983,

" Request for Relief from the Requirements of 10CFR Part 50, Section 50.48 (b) for Fire Areas No. 58, 59, 73 and 74."

(C) Letter from D M Musolf to NRR dated May 16, 1983,

" Clarifying Information in Support of Exemption Request for Fire Areas 58, 59, 73 and 74."

This letter is to confirm those items as discussed between D DiIanni and J Stang of the staff and Terry Pickens of Northern States Power in their telecon on August 23, 1983.

In addition to those modifications as outlined in Reference (B) the "A" train safe shutdown cable trays bounded by coordinates 6.1/G, 6.1/H, 7.3/G and 7.3/H in Fire Area 58 and 10.7/G,10.7/H, 11.7/G and 11.7/M in Fire Area 73 [see plant l layout drawings contained in Reference (C)] will be wrapped with an approved one-hour rated material. This will insure that cables in these trays will not suffer damage from the radiative effects of a fire near unprotected MCC 1K-2 l (B train) and MCC 2K-2 (B train) . This wrap will also provide protection against the possible accumulation of convective hot gases from such a fire in this relatively confined location. Thus, at least one train of safe shutdown cables /

! equipment remains free of fire damage.

l /0) l 8309130020 830902 PDR ADOCK 05000282 F PDR

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NORTHERN STATES POWER COMPANY Dir cf NRR .

September 2, 1983 Page 1 NSP has referenced "KA0 WOOL" in our previous submittals as the material to be used for providing one hour barriers. Due to the concern over heat build up inside the wrapped cable trays which could necessitate cable de-rating NSP is reviewing other materials approved for use as one hour barriers for their heat dissipation qualities. The material demonstrating the qualities which best meet the overall design conditions, including the need for heat dissipation will be utilized.

Please contact us if you have any questions related to this submittal or if we can furnish additional information related to this issue.

d Mw.

David Musolf g Manager - Nuclear Suppor ervices DMM/ TAP /bd cc: Regional Administrator-III, NRC NRR Project Manager, NRC NRC Resident Inspector G Charnoff

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