ML20133C961
| ML20133C961 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 09/30/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20133C948 | List: |
| References | |
| NUDOCS 8510070547 | |
| Download: ML20133C961 (3) | |
Text
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8 NUCLEAR REGULATORY COMMISSION o
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WASHINGTON, D. C. 20555
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SAFETY EVALUATION REPORT RELATED TO AMENDMENT N0. 46 TO FACILITY OPERATING LICENSE NPF-9 AND TO AMENDMENT N0.27 TO FACILITY OPERATING LICENSE NPF-17 DUKE POWER COMPANY INTRODUCTION By letter dated April 9,1985, Duke Power Company (the licensee) requested changes to a Technical Specification surveillance requirement which is part of an augmented inservice inspection program for snubbers. The change affects the second of three sampling plan options available for functional tests of snubbers.
This second sampling plan is defined by Specification 4.7.8.e(2) and requires that a representative sample of snubbers be tested each refueling in accordance with Specification Figure 4.7-1.
Figure 4.7-1 provides the acceptance criteria method for the functional test results and denotes a " reject" region and a
" continue testing" region.
If at any time the plotted test results fall within this " reject" region, then all snubbers are to be functionally tested. Surveil-lance requirement 4.7.8.e(2) and its accompanying Figure 4.7-1 are being changed to delete the " reject" region on Figure 4.7-1, to substitute an expanded " con-tinue testing" region, and to clarify the manner in which test results should be plotted sequentially in the order of sample assignment (i.e., each snubber should be plotted by its order in the random sanple assignment, not by the order of testing). References to the " reject" region in the text of Specification 4.7.8.e(2) and bases 3/4.7.8 are being deleted. Bases 3/4.7.8 is also supple-mented by(a footnote to note that if testing continues to between 100-200 snubbers or 1-2 weeks) and still the " accept" region of Figure 4.7-1 has not been reached, then the actual percent of population quality (the ratio of total number of failed snubbers to the cumulative number of snubbers tested) should be used to prepare for extended r 100% testing.
EVALUATION McGuire Technical Specification 3.7.8 requires that all safety related snubbers be operable for specified operating modes and is not changed by the proposed amendment. Only the surveillance requirement by which each snubber is to be demonstrated operable, in part by functional testing of a representative sample of snubbers each refueling, is charged, and then only with respect to the second of three available sample plans designated by Specification 4.7.8.e.
Under Specificatich 4.7.8.e(2), a representr.tive sample of snubbers, beginning with an initial selection of at least 37 snubbers, is functionally tested in accordance with a graph (Specification Figure 4.7-1) of "C", the_ total number of snubbers found not meeting the acceptance requirements of Specification 4.7.8f (i.e., failures), versus "N", the cumulative number of snubbers tested. The existing graph denotes three separate regions designated " accept," " continue testing" and " reject." The " accept" and " continue testing" regions are separated 8510070547 850930 i
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by a curve, C = 0.055N - 2.007; the " continue testing" and " reject" regions are presently separated by a curve, C = 0.055N + 2.007. To apply the graph, test results are plotted on Figure 4.7-1.
Under the existing Technical Specifications, if at any time the point plotted falls in the " reject" region all snubbers are to be functionally tested.
If at any time the point plotted falls in the " accept" region, testing of snubbers may be terminated. When the point plotted lies in the " continue testing" region, additional snubbers are to be tested until the point falls in the " accept" region or the " reject" region, or all the required snubbers have been tested. Deletion of the " reject" region, as implemented by this amendment, effectively changes that region of the graph to a " continue testing" region. Therefore, snubbers will continue to be tested until the i
plotted point falls in the " accept" region or until all the safety-related snubbers have been tested.
Statistical studies within the licensee's submittal of April 9,1985, and within a draft document by a task force of the Operations and Maintenance Group (OM-4) of the ASME Committee, " Examination and Performance Testing of Nuclear Power Plant Dynamic Restraints (Snubbers)" (ANSI /ASME OM4-1985) demonstrate that the proposed deletion of the " reject" region does not have a significant adverse effect on the effectiveness of the sampling plan. These statistical studies indicate that while the probability of false acceptance of a bad population under the proposed amendments is real, it is negligible. The Comission's review of these documents supports this conclusion. We also find that the revised plotting sequence is a more appropriate method for implementing the sampling plan. There-fore, the staff finds the proposed changes to be acceptable.
ENVIRONMENTAL CONSIDERATION The amendments involve changes in surveillance requirements. The staff has deter-mined that the amendments involve 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 occupa-tional exposure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration, and there have been no public comments on such finding. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR Section 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 amendments.
CONCLUSION The Commis.sion made a proposed determination that the amendments involve no significant hazards consideration which was published in the Federal Register (50 FR 34939) on August 28, 1985, and consulted with the state of North Carolina.
No public comments were received, and the state of North Carolina did not have j
any coments.
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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 these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: Darl S. Hood, Licensing Branch No. 4, DL Dated: September 30, 1985 4
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