ML20149M672
| ML20149M672 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 01/21/1997 |
| From: | Duffy J VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BVY-97-12, NUDOCS 9701240230 | |
| Download: ML20149M672 (1) | |
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l VE,RMONT YANKEE NUCLEAR POWER CORPORATION Ferry Road, Brattleboro, VT 05301-7002 REPLY TO ENGINEERING OFFICE p
580 MAIN STREET BOLTON. MA 01740 (508) 779-6711 January 21,1997 BW 97-12 United States Nuclear Regulatory Commission ATTN: Document Control Desk l
Washington, DC 20555 l
l
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, WNPC to USNRC, BW 96-73, dated June 7,1996 (c) Meeting, WNPC and USNRC, at NRR, August 1,1996 (d) Telecon, USNRC to WNPC, September 9,1996 l
Subject:
Withdrawal of a Request for Exemption from 10 CFR Part 50, Appendix R l
In Reference (b) Vermont Yankee requested an exemption from the provisions of 10 CFR Part 50, Appendix R, Section Ill.G, " Fire protection of safe shutdown capability." Specifically, Vermont Yankee requested an exemption from the 3-hour fire barrier requirements of Appendix R, Section lil.G.2.a. to permit use of a 1-hour fire rated enclosure around the Automatic Depressurization System (ADS) inhibit switch in the Control Room. The purpose of this letter is to withdraw the exemption requested in Reference (b).
As discussed in References (c) and (d), the 1-hour fire-rated enclosure is an enhancement installed to provide additional assurance that inadvertent opening of Safety Relief Valves (SRVs) will not occur. Spurious opening of the SRVs would require two hot shorts of the proper polarity without grounding to energize the ungrounded SRV circuits. Generic Letter 86-10, question 5.3.1, considers the probability of getting two hot shorts of the proper polarity without grounding on an ungrounded de circuit sufficiently Icw that further evaluation is not required. Therefore, protection of the inhibit switch enclosure is not subject to the fire barrier provisions of Ill.G.2.a and an exemption from Ill.G.2.a is considered unnecessary. Therefore, Vermont Yankee is withdrawing the exemption requested in Reference (b).
We trust that the information provided is acceptable; however, should you have any questions,
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/gl )db please contact this office.
Sincerely, VERMONT YANKEE NUCLEAR POWER CORPORATION s
j f,
NOo$k hbo$b71 James J. Duffy PDR Licensing Engineer y
c: USNRC Region I Administrator USNRC Resident inspector-WNPS USNRC Project Manager-WNPS
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