ML20043E878

Application for Amend to License DPR-28,changing Tech Specs to Support Replacement of Uninterruptible Power Supply at Plant

ML20043E878
Person / Time
Site:	Vermont Yankee File:NorthStar Vermont Yankee icon.png
Issue date:	06/07/1990
From:	Tremblay L VERMONT YANKEE NUCLEAR POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20043E879	List: ML20043E878 ML20043E887
References
BVY-90-066, BVY-90-66, NUDOCS 9006130484
Download: ML20043E878 (2)

Text

.. __ ._ . _ . . _. __ ._

VERMOINT YANKEE NUCCEAR POWER CORPORATION

.y s - Ferry Road, Brattleboro. VT 053017002 ENGINE OFFICE V -'

500 MAIN S TREE T DOI,10N, M A 0 t ?40

($08) 779 (J11 June 7,1990

" B 6 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

References:

a. License No. DPR 28 (Docket No. 50-271)

b. Letter, VYNPC to USNRC, BVY 89-106, dated 11/9/90

c. letter, USNRC to VYNPC, NVY 89 224, dated 11/9/90

Subject:

Technical Specification Change to Support Replacement of the Uninterruptible Power Supply at Vermont Yankee

Dear Sir:

1 In Reference (b), Vermont Yankee committed to replace the existing Uninterruptible Power Supply (UPS) with an alternative system, to be made operable prior to start up from the planned 1990 Refueling Outage. NRC acknowledged Vermont Yankee's commitment to replace the UPS in Reference (c).

The existing UPS source was added in 1976 when the " swing bus" design was removed at Vermont Yankee. The UPS provides an independent power source to the Low Pressure Coolant

Injection (LPCI) valves that are required for a single Design Basis Accident event. This event is a

! double-ended recirculation discharge break in one loop, with the single failure of the diesel supplying the LPCI train in the unbroken loop,in conjunction with a loss of norma! power. The UPS source ensures that power to the LPCI injection valves is available for both trains, despite the failure of a diesel.

I The existing UPS includes solid state inverters. As a result of our investigations to improve l the reliability of the UPS system, our plans are to replace the solid state inveners with motor-generator sets.

To support this change, the description of the UPS which exists on Vermont Yankee Technical Specification page 178, which refers to a " solid state inverter", must be deleted. Since this change is in the bases section of the Technical Specifications, a formal proposed Technical S ycification change in accordance with 10CFR50.90 is not warranted. Accordingly, attached please find a revised p.178 of the Vement Yankee Technical Specifications which modifies the l Technical Specification bases section to accommodate our planned improvements to the UPS at l Vermont Yankee, We understand that NRC plans to include this revised page as pan of a currently pending license amendment which is ready for issuance, l

900613o484 900607 pa ApocKosoog2 g 001 Ir

United States Nuclear Regulatory Commission .

June 7,1990 Page 2 Should you have any questions regarding the above information, please contact this office. .

1 Very truly yours,

. VERMONT YANKEE NUCLEAR POWER CORPORATION SQ ,

CO i /\.

12onard A.Tremblay,Jr.

Senior Licensing Engineer

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cc: USNRC Region 1 Administrator USNRC Resident Inspector. VYNPS USNRC Project Manager. VYNPS Mr. Vernon Rooney, USNRC/NRR ,

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