ML19341B826
| ML19341B826 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 02/23/1981 |
| From: | Rich Smith VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| FVY-81-31, NUDOCS 8102270759 | |
| Download: ML19341B826 (3) | |
Text
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VERMONT Y AN KEE NUCLEAR POWER CORPOR ATION s
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SEVENTY SEVEN GROVE STREET 2
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RUTLAND. VERMONT 05701 FVY 81-31
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LC ENGINEERING OFFICE (G
FR AMINGH AM. M ASS ACHUSETTS o17of e
TELtPHONE 817-872 0100
{j February 23, 1981 United States Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Office of Nuclear Reactor Regulation Mr. D. G. Eisenhut, Director Division of Licensing Re ferences:
(a)
License No. DPR-28 (Docket No. 50-271)
(b)
Letter, VYNPC to USNRC, WVY 80-197, dated July 25, 1980 (c)
Letter, VYNPC to USNBC, FVY 81-7, dated January 9, 1981 (d) Letter, USNRC to VYNPC, dated January 13, 1981: Order for Modification of License and Grant of Extension of Exemption (e) Letter, USNRC to VYNPC, dated February 28, 1978
Subject:
Torus Modifications at Vermont Yankee
Dear Sir:
The purpose of this letter is to clarify the position taken by Vermont Yankee in -Reference (c) and to further explain the basis for that position.
- Verrtont Yankee originally documented its proposed schedule for completing Mark I Program activities in Reference (b).
In a telephone conversation on January 9,1981, the NRC directed that an immediate response [ Reference (c))
be submitted to aid them in writing the Order for Modification of License forwarded by Reference (d).
It now appears that this response was not factored into the resulting order by the NRC.
Therefore, Vermont Yankee feels it imperative that the basis of our schedule for completing the subject modifications be clearly presented to provide the NRC with a full understanding of our situation.
As stated in Reference (c), all of the modifications identified in Reference -(d) have been completed with the exception of external torus piping resupport, which may or may not be necessary depending on the outcome of analysis.
Our analysis of torus attached piping is in progress, however. the need for modifications as well as, the extent and nature of any modifications which may be needed cannot be determined until this analysis is completed.
Our engineering consultants inform us that, due to the problems origirmily encountered in running the computer code developed for this task, the results
-of the analysis will not be available to us until mid 1981. We have requested O sie 81'02270fJ$
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United States Nuclear Regulatory Commission February 23, 1981 Office of Nuclear Reactor Regulation Page 2 e
our consultants to attempt to accelerate this effort as much at possible, but because they are performing similar analyses for other licensees on schedules similar to ours, it will be difficult to improve the schedule significantly.
It should be emphasized that the problem with the analytical program effects all Mark I plants, not just Vermont Yankee.
It is Vermont Yankee's intent to make every effort to complete the required analysis and install any modifications which may be shown to be necessary within the time frame required by your Order.
However, this entails the following interrelated sequence of possible events.
The necessity, extent, and nature of any modification /resupport must be
?
determined. These determinations cannot be made until the analysis has i
been completed. Since this analysis will not be completed until mid 1981, only five months remain of the time allowed by the order for I
design, procurement, and installation.
Modifications to resupport torus piping would more than likely require installation of additional snubbers.
These snubbers would not be "off the shelf" items since they must be specifically designed to satisfy the i
loading conditions and could not be ordered prior to completing the i
design analysis. We have researched vendors and have found that the lead time for similar kinde of snubbers is currently six to ten months. This j.
. would exceed the time available to comply with the Order.
If welding to the torus shell is required, a shutdown of extended duration would be necessary to allow draining the torus. Such a shutdown cannot be scheduled until the necessity for any modifications involving welding is precisely determined.
If this course of action is found to be necessary, the time available to comply with the order would probably be j
- exceeded, l
This information was provided verbally to your staff before forwarding L..
. Reference (c) togethea with the fact that the next major refueling outage after the current October 1981 outage is scheduled for' spring of 1983 We feel ~that,it is-evident that the uncertainties in our schedule, many of which
- are beyond our centrol, combine to reduce the likelihood that further modifications, if 'necessary, can be completed within the time allowed by the
. Order.- If further modifications are not necessary or turn out to be relatively minor, Vermo' t Yankee sho4d be able to comply with the Order. In n
Reference. (e), the NRC determined that continued operation was justifled for several years while -major _ orus modifications were designed and implemented.
t On the basis of this finding and given-the substantial' improvements already made to the torus and the uncertainty as to the magnitude of improvement which may be gained through further < modifications, it. is patently clear that continued operation beyond November 30,~1981 is justified.
If we find further modifications.necessary, but are unable to implement them by November 30, 1981,.we propose to implement such modifications no later than the next regular refueling. outage..
~
'We trust that the information pres'ented above explains the basis for the
- position taken by Vermont Yankee in Reference (c). We will: inform you as
- information becomes available which removes the uncertainties described above
United States Nuclear Regulatory Commission February 23, 1981 Office of Nuclear Reactor Regulation Page 3 and adversely impacts our ability to meet the requirements of the Order forwarded by Reference (d).
Since the date selected in the Order is distinctly at variance with the actual facts in our case, rectification of this problem by you will cost likely be necessary.
Please indicate your intended action.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION f
/
R. L. Smith Licensing Engineer l
l