ML20059G860
| ML20059G860 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 10/29/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059G827 | List: |
| References | |
| NUDOCS 9311090142 | |
| Download: ML20059G860 (2) | |
Text
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UNITED STATES l'
NUCLEAR REGULATORY COMMISSION gv,8 WASHINGTON. D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RE0 VEST FOR RELIEF FROM INSERVICE INSPECTION RE0VIREMENTS RELATED TO SAFETY-RELATED SNUBBERS SECOND TEN-YEAR INTERVAL. MCGUIRE NUCLEAR STATION. UNIT 1 DOCKET NO. 50-369
1.0 INTRODUCTION
By letter dated November 30, 1992 (Reference 1), the Duke Power Company (DPC or licensee), pursuant to 10 CFR 50.55a{g)(5)(iii), requested relief from the requirements of the 1986 Edition of the ASME Boiler and Pressure Vessel Code,Section XI, Article IWF-5000, (hereafter, referred to as the Code) for the McGuire Nuclear Station, Unit 1.
The McGuire Technical Specification (TS) Surveillance Requirement 4.7.8 states that each snubber required by TS 3.7.8, be operable by performing an augmented inservice inspection program (as specified by TS 4.7.8a-1).
Part of this i
augmented inspection program (TS 4.7.8e), requires that during the first refueling shutdown and at least once per refueling outage, a representative l
sample of snubbers be tested using one of three stated sample plans.
In addition, TS 4.0.5 requires that the ASME Code Section XI be followed in accordance with 10 CFR 50.55a(g).
In Attachment Section IV, " Alternate Testing" to Reference 1, the licensee l
stated that safety-related snubbers will be functionally tested in accordance with plan Number 2 of three alternative plans in TS 4.7.8e.
This plan for j
snubber selection differs from that in Section XI of the Code. The Code i
provides for only one sampling plan, which is identical to one of the three TS l
sampling plans.
Since it seemed redundant to comply with both the Code and the TS sampling plans for the snubber tests, the licensee submitted the relief request.
On March 26,1985 (Reference 2), the staff approved a similar request by the licensee for relief from the ASME Section XI requirements during the first ten-year interval for McGuire. The present request involves the safety-related snubbers selection plan to be performed during the second ten-year interval for inservice inspection at McGuire, Unit 1.
2.0 EVALUATION For snubber inservice functional tests, the McGuire TS provides three NRC-approved sampling plans, one of which (sample plan Number 1 of TS 4.7.8e) is identical to that required by the ASME Code Section XI (Reference 3). The 9311090142 931029 PDR ADOCK 05000369 O
1 other two plans were developed on the basis of operating experience, design practice and statistical studies to permit the licensee flexibility in selecting an alternate sampling plan from the TS.
Performance of any of these three plans will provide a confidence level greater than 95% that at least 90% of the snubbers will be operable within accbptable limits. Therefore, TS 4.7.8e requires only one of three stated i
sample plans to be performed for inservice inspection of snubbers. Requiring compliance with more than one sampling plan will be unnecessary and excessive.
Therefore, we find that the performance of the Code sampling plan requirements will be redundant to the performance of TS 4.7.8e sample plan Number 2 since f
use of any of the three sampling plans from the McGuire TS will serve the intended purpose of the Code in ascertaining the functionality of safety-related snubbers during normal plant operation.
3.0 CONCLUSION
Based on our evaluation in Section 2.0, we conclude that compliance with thel Code required sampling plan, in addition to the McGuire TS sampling plan
{
Number 2, is impractical. Therefore, pursuant to 10 CFR 50.55a(g)(6)(i), we:
t conclude that the licensee's request for relief from the Code sampling plan requirements during the second ten-year interval for McGuire, Unit 1, should be granted.
REFERENCES 1.
Duke Power Company letter to NRC dated November 30, 1992.
I 2.
NRC letter to Duke Power Company dated March 26, 1985.
3.
ASME Boiler and Pressure Vessel Code Section XI,1986 Edition, Article
[
IWF-5000.
Date:
October 29, 1993 e
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