ML20133F650

Responds to RAI Re Exemption Request by Clarifying 961212 Response Re Use of Vernon Tie in Event of Reactor Building Fire

ML20133F650
Person / Time
Site:	Vermont Yankee
Issue date:	01/08/1997
From:	Duffy J VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
BVY-97-4, NUDOCS 9701140309
Download: ML20133F650 (2)

Text

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) VERMONT YANKEE i NUCLEAR POWER CORPORATION i

• i l .- Ferry Road. Brattleboro, VT 05301-7002

, t MPLY TO

) ENGINEERINGOFFICE

, 580 MAIN STREET 4

BOLTON, MA 01740

, (508) 779-6711 -

i

! January 8,1996 j BW 97-4

! United States Nuclear Regulatory Commission

! ATTN: Document Control Desk Washington, DC 20555  !

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References:

(a) License No. DPR-28 (Docket No. 50-271) l (b) Letter, USNRC to WNPC, NW 96-186, dated December 12,1996

. (c) Letter, WNPC to USNRC, BW 96-43, dated April 4,1996 j (d) Letter, WNPC to USNRC, BW 96-158, dated December 13,1996

(e) Telecon, USNRC to WNPC, dated January 6,1997 j (f) Letter, WNPC to USNRC, BW 96-67, dated May 21,1996

Subject:

Clarification Regarding Use of Vernon Tie for Appendix R Compliance l

In Reference (b) the NRC requested additional information regarding an exemption request  !

submitted by Vermont Yankee in Reference (c). Vermont Yankee provided the requested information in Reference (d), stating its intention to "use the Vemon Tie in lieu of the 'A' EDG Independent of the availability of offsite power" (question 2.1.5). In Reference (e), the NRC asked if this response meant Vermont Yankee intended to de-energize all station loads.

Vermont Yankee responded that only emergency bus 4, which powers safe shutdown equipment, would be de-energized and then re-energi7d from the Vemon Tie in order to provide a reliable source of power in the event of a comm room or cable vault fire.

In Reference (e) the NRC requested that Vermont Yanke ein clarify its response to question 2.1.1 of Reference (b) regarding the use of the Vemon Tie in tne event of a Reactor Building j fire, in Reference (d), Vermont Yankee stated that "since loss of offsite power must be I assumed for Reactor Building Ill.G.3 compliance, the Vemon Tie would also be credited for use I6 (in the normal operational mode from the Control Room) in the event of a fire in those Reactor [

Building fire zones which may utilize Ill.G.3 compliance strategies." However, since loss of normal sources of offsite power is not expected to occur for fires in the Reactor Building, use of the Vemon Tie provides defense-in-depth and would only be used in the event normal sources

]p of power were not available.

140053 9701140309 970108 PDR ADOCK 05000271 P PDR

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, VERMONT YANKEE NUCLEAR POWER CORPORATION Unned States Nuclear Regulatory Commission January 8,1997 PeGe 2 of 2

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i We trust that this submittal provides the requested information. However, should you have I questions or require additional information, please contact this office.

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1 Sincerely, VERMONT YANKEE NUCLEAR POWER CORPORATION M/?zsof hs James J. Duffy

Licensing Engineer c: USNRC Region 1 Administrator USNRC Project Manager-VYNPS USNRC Resident inspector-VYNPS 1

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