ML20091A876
| ML20091A876 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 05/22/1984 |
| From: | Musolf D NORTHERN STATES POWER CO. |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| TAC-53558, TAC-53559, NUDOCS 8405300115 | |
| Download: ML20091A876 (2) | |
Text
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Northem States Power Company 414 Nicollet Mall Minneapoks. Minnesota 55401 Telephone (612) 330-5500 May 22,1984 Director Office of Nuclear Reactor Regulation U S Nuclear Regulatory Commission Washington, DC 20555 PRIAIRIE ISLAND NUCLEAR GENERATING PLANT Docket Nos. 50-282 License Nos. DPR-42 50-306 DPR-60 Information in Support of the Request for Exemption f rom the Requirement of Section III.0 of Appendix R to 10 CFR Part 50 Dated April 5, 1984 Reference (a) Letter from D M Musolf to Director of NRR Dated April 5,1984 "Information in Support of Exemption Requests Submitted January 23, 1984 and Request for Exemption from the Requirements of Section III.0 of Appendix R to 10 CFR Part 50" Pursuant to the Staff's review of Attachment 1 to Reference (a) a question was raised as to the seismic design classification of the piping which would carry the lube oil from Sump A to the aerated sump tank, thIe first vented closed container. This letter is intended to confirm the response as given in numerous telephone conversations between NSP and the Staff.
l The piping from the Sump A pumps, including the pump, to the first valve l
(WL-29-17, WL-29-18, 2WL-29-17 and 2WL-29-18) is Seismic Category III.
The runs are approximately 6 feet long. The piping from the first l
valve, up to and including containment isolation valves (SV-33632, SV-33633, SV-33756 and SV-33757) is Seismic Category I.
The remaining portion of the piping in the Auxiliary Building is Seismic Category III.
Those portions of the piping which have been designed to Seismic Category III have been reviewed against the requirements of Reg. Guide 1.29, Para-graph C-2 and it has been concluded that if failure of those portions of this piping which were designed to Seismic Category III were to occur during a seismic event the functions of the plant features described in Paragraph C-1 (a thru q) of Reg. Guide 1.29 would not be affected and the plant could be brought to cold shutdown.
8405300115 840522 PDR ADOCK 05000282 F
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Dir, NRR May 22, 1984 Page 2 Northem States Power Company These conclusions are supported by the facts that of the subject piping inside containment only approximately 6 feet is not Seismic Categon I.
That 6 feet contains only approximately 2h feet of horizontal piping.
Any failure of the piping in this area would lead to the lube oil returning to the sump area. As was stated in Reference (a) there is no safe shut-down equipment in the sump area. The Seismic Category III piping in the Auxiliary Building is located adjacent to the hold-up tank valve gallery and is separated from any safe shutdown equipment by concrete walls.
Please contact us if you have any questions or if additional information is required.
[
David Musolf Manager-Nuclear Support Services DMM/ TAP / dab cc:
Sec of the Commission (Original and 2 copies)
Regional Administrator-III NRR ?roject Manager, NRC Resident Inspector, NRC G Charnoff O
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