ML20136E098
| ML20136E098 | |
| Person / Time | |
|---|---|
| Site: | Monticello  |
| Issue date: | 12/23/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20136E077 | List: |
| References | |
| NUDOCS 8601060427 | |
| Download: ML20136E098 (2) | |
Text
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UNITED STATES 8
NUCLEAR REGULATORY COMMISSION g-o WASHINGTON, D. C. 20555
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGU"L'ATION i
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SUPPORTING AMENDMENT NO. 36 TOFACILITYOPERATINGLICENSE'kO.DPR-NORTHERN STATES POWER COMPANY j.{
MONTICELLO NUCLEAR GENERATING PLANT f
DOCKET NO. 50-263
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1.0 INTRODUCTION
By letter dated September 24, 1982 Northern States Power Company (NSP/the i
licensee) proposed revised Technical Specifications (TSs) to permit vacuum breaker cycling (i.e. opening, holding open for up to one minute, and
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closing), one vacuum breaker at a time during containment inerting and deinerting operations.
2.0 EVALUATION I;
The proposed change will allow cycling of the drywell-to-wetwell vacuum breakers during inerting and deinerting operation to aid in changing the
,,3f gas mixture in the drywell-to-torus vent pipes and vent header. This 1*
cycling operation is quite similar to the operability test currently pi required every 31 days by the Standard Technical Specification.
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The operation of the vacuum breakers (no more than one vacuum breaker at a time) in these modes will be accomplished from the control room with an
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operator present to assure closure of the vacuum breaker following the 1
3 i completion of the operation. Based on our evaluation nf the licensee
). L submittal, we agree with their conclusion that cycling the vacuum breakers j
during inerting will further assure that oxygen concentration in the vent
. pipe and vent header remains below the Technical Specification limits. We n
- 4 also find that the cycling of the vacuum breakers during deinerting operation
~ ill eliminate' potential pockets of inert gas. As stated above, this w
operation is not much different than the monthly valve exercise test.
If a vacuum breaker would stick open, the plant would be placed in cold sutdown r
the existing TSs. Therefore, the proposed Technical as required by'are acceptable. Subsequent to the initial notice in the ii Specifications 4.
Federal Register, the Northern States Power Company, by letter dated f
December 3,1985, corrected the typographical error. These revisions do not i
change the substance of the amendment and do not alter the staff's initial detennination that this amendment would involve no significant hazards considerations.
l' G601060427 851223 PDR ADOCK 050 3
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3.0 ENVIRONMENTAL CONSIDERATION
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l This' amendment involves a change in the installation or use of a;Ta'cility component located within the restricted area as defined in 10 CFR Part 20.
3 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 Comission j
has previously issued a proposed finding that this amendment involves no i
significant hazards consideration and there has been no public coment on L
such finding. Accordingly, this amendment meets the eligibility criteria for i
categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 1
51.22(b) no environmental impact statement or environmental assessment need i
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be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
l We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public
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will not be endangered by operation in the' proposed manner, and (2) such i
activities will be conducted in compliance with the Comission's regulations and the issuance of the amendment will not be inimical to the comon defense 1
J and security or to the health and safety of the public.
Sr Principal Contributor:
F. Eltawila.
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L Dated: December 23, 1985.
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