ML20127E569
| ML20127E569 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 06/06/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20127E549 | List: |
| References | |
| NUDOCS 8506240588 | |
| Download: ML20127E569 (2) | |
Text
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UNITED STATES g
NUCLEAR REGULATORY COMMISSION j
WASHINGTON, D. C. 20555
%...../
SAFETY EVALUATION BY TPE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 88 TO FACILITY OPERATING LICENSE NO. DPR-28 VERMONT YANKEE NUCLEAR POWER CORPORATION VERMONT YANKEE NUCLEAR POWER STATION DOCKET NO. 50-271
1.0 INTRODUCTION
By letter dated July 22,1982 (Reference 1), Vemont Yankee Nuclear Power Corporation (the licensee /VYNPC) proposed a change to Section 3.7.A of the Technical Specifications for the Vemont Yankee Nuclear Power Station. The proposed change would raise the suppression pool temperature limit during normal operation from 90*F to 100 F.
In that transmittal and in the subsequent one (Reference 2), the licensee provided its technical basis for the proposed change.
Subsequent to these letters, the licensee provided its " Plant Unique Analysis Report" (PUAR, Reference 3) which contained a description of the specific application of the generic Mark I pool dynamic loads and methods to Vermont Yankee and the plant unique loads used in assessing the capability of the containment and associated components to accommodate pool dynamic loadings. This report supersedes the previous transmittals referenced above and consequently the PUAR serves as the staff's oasis for its evaluation of the subject proposed change to the Technical Specifications.
2.0 EVALUATION In the PUAR, the licensee analyzed safety relief valve (SRV) transients based on an initial suppression pool temperature of 100 F.
The licensee has stated that the maximum bulk pool temperature will not exceed 175 F during any of the NRC-required transient analyses. The temperature remains below this level because Vermont Yankee has committed to remain in this su;,pression pool cooling mode for the entire length of the transient (i.e.,
not switch over to a reactor shutdown cooling mode requiring removal of the RHR system from suppression pool cooling). Based on data supplied by the licensee to characterize the Vermont Yankee RHR performance, we estimate that such operation will maintain a local-to-bulk pool temperature difference of 20*F.
This implies that local pool temperature will stay below the limits imposed by the staff.
For Vermont Yankee, the maximum allowable local pool temperature is 200 F (Reference 2). Allowing a local-to-hulk pool ter:perature difference of 20*F results in an allowable bulk pool temperature of 180*F. As indicated above, the staff has agreed that the maximum bulk nool temperature obtained acid not exceed 175*F.
8506240588 850606 PDR ADOCK 05000271 P
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. 3.0
SUMMARY
Based on the information provided by the licensee, we have concluded that the proposed changes to raise the suppression pool temperature limit during normal operation from 90"F to 100 F are acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
S This amendment involves changes in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
5.0 CONCLUSION
We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
6.0 REFERENCES
1.
Letter,iluly 22, 1982, L. H. Heider, Vermont Yankee Nuclear Power Corporation, to NRC, Subiect:
Proposed Change to Suppression Chamber Temperature Limit.
2.
Letter, July 20, 1983, J. B. Sinclair, Vennant Yankte Nuclear Power l
Corporation, to D. B. Vassallo, NRC,
Subject:
Suppression Chamber Temperature Limit.
3.
" Plant Unique Analysis Report of the Torus Suppression Chamber for Vermont Yankee Nuclear Power Station," Technical Report TR-5319-1, Teledyne Engineering Services, Rev. 1, April 8, 1983.
Principal Contributor:
J. Lane Dated: June 6, 1985