ML20128D093
| ML20128D093 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/02/1992 |
| From: | Rooney V Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20128D065 | List: |
| References | |
| NUDOCS 9212070144 | |
| Download: ML20128D093 (3) | |
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UNITED STATES y
8 NUCLEAR REGULATORY COMMISSIONJ o
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WASHINGTON, D. C. 20666 9ey.....
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 71 TO FACILITY OPERATING LICENSE NO. NPF-49 NORTHEAST NUCLEAR ENERGY COMPANY. ET AL.
MILLSTONE NUCLEAR POWER STATION. UNIT NO. 1 DOCKET NO. 50-423 1.0. INTRODUCTION By letter dated May 1,1992, as supplemented June 23, 1992, the Northeast Nuclear Energy Company (NNECO), submitted a request for' changes to the-Millstone Nuclear Power Station, Unit No. 3 Technical' Specifications (TS).
The requested changes would revise the visual inspection surveillance requirements-associated with the snubbers so that the first= interval determined using the surveillance criterion approved in License' Amendment 62-is based on the results of inspections performed during Millstone Unit.No.- 3's third refueling outage. The proposed Technical S)ecification would extend the-time by which inspection _is required to the fourti refueling outageT(now:
scheduled for June 1993) in accordance with the new-snubber surveillance criterion which had been approved by the staff.in License' Amendment 62:
(September 3,1991) for. use in inspection intervals. subsequent to-the 1 resent interval. The June 23, 1992, letter provided clarifying information t1at.did-not change the initial _ proposed no significant. hazards consideration determination.
2.0 EVALUATION License Amendment No. 62, issued September 23,L1991 revised the criterion for.
determining the visual inspection intervals associated with the-seismic sway-arrestors (snubbers) for Millstone _ Unit No. 3.
Appendix 62-fixed-the use of.-
the new criterion so that it was> based on the previous inspection-interval as:
determined by-the requirements-in effect before Amendment 62. -The present Technical Specifications would require inspection l sooner? than -.an Loutage of-sufficient duration according to-present schedules.
A visual inspection is the observation of the condition:of installed snubbers to identify those that-are damaged, degraded.or. inoperable as caused by-physical means, leakage, corrosion,-- or environment-exposure. 2To verify that a-snubber can operate within specific performance limits, the licensee-performs:
functional testing that typically involves removing.the snubber-and testing.it on'a specially-designed-test stand.
Functional testing provides a'95 percent; g
confidence' level that 90 percent to 100 percent of the snubbers operate within the specified acceptance limits. The performance of visual examinations'is a.
separate-process;that complements the functional testing-program and provides -
additional confidence in snubber noerability.
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. The-proposed change would allow NNECO to utilize the results of inspections performed during Hillstone Unit No. 3's third refueling outage, in con & ction with Technical Specification Table 4.7-2 rather than the interval which as in effect before Amendment No. 62.
The previous visual inspection interval was based on an 18-month refueling interval which did not account for the trend to longer fuel cycles or the impact of extended outages.
The proposed change will reduce occupational radiation exposure.
In addition, NNEC0 performed limited visual inspections in December 1991 since plant conditions allowed earlier than the recuired interval (i.e.,12 months 125 percent).
The inspections were performec only on the small (Pacific-Scientific PSA-1/4 and PSA 1/2) snubber population, due to their.
susceptibility to high drag loadings resulting from corrosive environmental-conditions.
All 229 snubbers, both accessible and inaccessible, in this grouping were inspected with no visual-signs of damage or impaired operability.
The results of these inspections provide an increased level of confidence that operability will be maintained until Millstone Unit No. 3's fourth refueling outage.
The proposed change does not change the criterion for determining visual inspection intervals,_which was approved in License Amendment 62, but changes--
the time at which the new criterion becomes effective.
Based on the favorable visual inspections in December 1991, and the reduced occupational radiation exposure, the proposed change is acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Connecticut State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a surveillance requirement. The NRC 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-occupationalsradiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (57 FR 28203). Accordingly, the 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 the amendment.
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5.0 CONCLUSION
The Commission has 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, (2) such activities.will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
V. L. Rooney Date:
December 2, 1992
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