ML20023E211
| ML20023E211 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 06/13/1983 |
| From: | Heider L VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0661, RTR-NUREG-661 FVY-83-55, NUDOCS 8306150161 | |
| Download: ML20023E211 (2) | |
Text
VERMONT YANKEE NUCLEAR POWER CORPORATION e
2.C.2.1 FVY 83-55 R D 5, Box 169. Ferry Road, Brattleboro, VT 05301 s
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ENGINEERING OFFICE t'
June 13, 1983 1671 WORCESTER ROAD FRAMINGHAM, MASSACHUSETTS 01701 TELEPHONE 617-872-8100 United States Nuclear Regulatory Commission Washington, D. C. 20555 Attention:
Office of Nuclear Reactor Regulation Mr. D. G. Eisenhut, Director Division of Licensing
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter, USNRC to VYNPC, dated January 13, 1981, " Order For Modification of License" (c) Letter, USNRC to VYNPC, dated November 25, 1981
Subject:
Request For Extension of Implementation Date For Torus Modifications at Vermont Yankee
Dear Sir:
By Reference (b), as modified by Reference (c), the NRC issued an Order for Modification of License for Vermont Yankee. The Order requires that we complete all necessary modifications to assure that the facility conforms to the acceptance criteria in Appendix A of NUREG-0661 by the beginning of Cycle 10.
For the reasons discussed below, we hereby request that the NRC issue an extension of the above order to require that all torus-related modifications be complete no later than ninety (90) days following startup from our current refueling outage.
The extension of order date applies only to torus attached piping supports which are currently being installed.
All torus internal modifications, safety relief valve discharge line modifications, and other torus-related activities have been completed. About 98% of the overall torus-related modification work is complete.
During the current refueling, the last phase of the torus upgrade program was undertaken.
This effort involved installation of the last few torus internal modifications and to date the installation / modification of 93 supports to torus attached piping.
Of the twelve (12) large bore piping runs affected, only five runs have some supports which have not as yet been installed. Of those five runs, two require one additional support and one requires two additional supports to meet all load combinations; in addition, some dead-weight supports will require modification. On the remaining two piping runs 27 supports have already been installed; however, several additional supports are needed to satisfy Mark I Program requirements.
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United States Nuclear Regulatory Commission June 13, 1983 e
Attention: Office of Nuclear Reactor Regulation Page 2 The analysis of these lines was particularly difficult for our consultant since the main runs each contain several branch lines which are not easily anchored and isolated from torus-induced dynamic loads. The analyses indicated that one torus load (Condensation Oscillation) was felt well away from the penetration to the torus itself. Hanger loads for these lines were the last set received prior to performing the support design analysis.
It is our intention to install the remaining hangers af ter return to normal operation. At the completion of the program, all piping runs will meet hydrodynamic, dead weight, thermal, and seismic loads in accordance with the Mark I Program requirements.
This approach is similar to that taken by Northeast Utilities' Millstone Unit I where some torus attached piping work was accomplished during operation.
By completing the modii'ication work before the proposed date, Vermont Yankee would still precede nine other affected plants in the completion of Mark I Program requirements, and thus continue to be in the first group of plants to complete NUREG-0661 requirements.
In the short interim period, Vermont Yankee will continue to operate in accordance with Mark I Containment Short Term Program Criteria, as defined in NUREG-0408, " Mark I Containment Short-Term Program Safety Evaluation Report",
dated December 1977.
We trust that the information presented above is adequate justification to enable you to act on this matter in an expidited fashion. Should it become necessary, we are prepared to meet with you at the earliest possible convenience.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION L. H. Heider Vice President LilH/ces r
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