ML20101T732
| ML20101T732 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 02/01/1985 |
| From: | Murphy W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| References | |
| FVY-85-12, NUDOCS 8502060325 | |
| Download: ML20101T732 (2) | |
Text
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VERMONT YANKEE NUCLEAR POWER CORPORATION RD 5, Box 169. Ferry Road, Brattleboro, VT 05301 7
p ENGINEERING OFFICE 1671 WORCESTER ROAD FRAMINGHAM, MASSACHUSETTS 01701 TELEPHONE 817472-4100 February 1, 1985 U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Attention:
Office of Nuclear Reactor Regulation Mr. Domenic B. Vassallo, Chief Operating Reactors Branch No. 2 Division of Licensing
References:
a)
License No. DPR-28 (Docket No. 50-271) b)
Letter, VYNPC to USNRC, FVY 82-04, dated 1/19/82 c) letter, VYNPC to USNRC, FVY 83-51, dated 6/6/83 d) letter, VYNPC to USNRC, FVY 84-14, dated 2/28/84
Dear Sir:
Subject:
Vermont Yankee Scram System Design - Hydraulic Control Unit Support Modification Installation By letter dated February 28, 1984 [ Reference d)], we informed you that the results of our additional analysis of the Vermont Yankee Scram System determined that the associated Hydraulic Control Units (HCU's) supports required modifica-tion to bring their frequency response in,line-with the assumptions made in our original analysis and FSAR criteria for structural integrity.
In accordance with our commitment to install these modifications by the end of 1984, we herein notify you that the HCU support modifi_ cations have been installed.
In our letter of June 6,1983 [ Reference c)], we stated that the scram discharge volumes, new instrument volumes, instrumentation, associated piping
- and valves were installed seismically; however, the seismicity of the total system could not he analytically verified until the HCU structure was either sufficiently stiffened or its flexibility properly accounted for in our analy-ses. During the integrated closeout review, we have determined that additioral mooifications to the insert and withdrawl lire pipe supports are necessary.
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U.S. Nuclcar' Regulatory Commission February 1,'1985 Page 2 VEHMONT YANKEE NUCLEAR POWER COMPOHATION Based on the analysis contained in NUREG 0803 and our evaluation which verified the NUREG's applicability to Vermont Yankee [ Reference b)], we believe that operation of the plant, while additional modifications to our insert and withdrawal line pipe supports are made, is justified. Our position is based on the fact that the potential consequences of leakage from the Scram Discharge System were thoroughly analyzed in NUREG 0803 and found not to be a matter of safety concern.
Our present schedule calls for completing the required designs by July of this. year. We would anticipate making any required modifications during opera-tion, if possible, or no later than the end of the 1985/86 outage.
Should you have any questions or require additional information in this matter, please contact us.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION N
Warren P. M rphy Vice President and
-Manager of Operations WPM /dm
-