ML19350D060
| ML19350D060 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 04/07/1981 |
| From: | Conway W VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | Eisenhut D Office of Nuclear Reactor Regulation |
| References | |
| FVY-81-58, NUDOCS 8104130226 | |
| Download: ML19350D060 (4) | |
Text
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VERMONT YAN KEE NUCLEAR POWER CORPORATION
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SEVENTY SEVEN GROVE STREET 2.C.2.1 ItUTLAND, VERF10NT 05701 FVY 81-58 naPLv vos ENGINEERING OFFICE 1671 WORCESTER ROAD FR AMINGH AM. M ASSACH USETTS 01701 TELEPHONE G17 873 5100 April 7, 1 Q>
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United States Nucicar Regulatory Commission
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1 Washington, D.C.
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Division of Licensing o
yf Darrell G. Eisenhut, Director N
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References:
(1) License No. DPR-28 (Docket No. 50-271)
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(2) NRC Letter to All Power Reactor Licensees (except SEp Licensecs) dated November 20, 1980
Dear Sir:
Subject:
Technical Specification Revisions for Snubber Surveillance Your letter (Reference 2) requested that we submit an application to incorporate the applicable portions of the model Technical Specifi-cations into Appendix A of the Vermont Yankee Technical Specifications.
We have completed a detailed review of the model technical speci-fications and do not share your view that the proposed additional
" changes, clarifications and improvevents" will provide additional assurances of snubber operability.
Vermont Yankee finds insufficient justification for impicmenting the additional requirements presented by Reference (2). The bases for our position are as follows:
1)
Your proposed Tech. Spec. 4.7.9b Visual Inspection Acceptance Criteria states... "when the fluid port of a hydraulic snubber is found to be uncovered, the snubber shall be determined inoperable and cannot be determined operable via functional testing for the purpose of es-tablishing the next visual inspection interval."
Comment Vermont Yankee's Tech. Spec. states that visual inspec-1 tions are required to verify snubber operability.
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VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission April 7, 1981 Page 2 Vermont Yankee's approach, which has received concurrence of the NRC inspector, is that a lack of fluid in a snubber reservoir does not necessarily render that snubber inoper-able. 07erability is determined by subjecting the snubber to a fun;tional test in the as-found condition.
If the snubber fails to pass the functional test, it is consid-ered inoperable for the purposes of establishing the next visual inspection interval. This is consistent with the intent of the technical specification, i.e., to maintain an acceptable level of suppressor operability.
In all cases, causes of fluid leaks are investigated and corrected.
Vermont Yankee maintains that this is a sound and conserva-tive approach.
2)
Your proposed Tech. Spec. 4.7.9c requires that, "In addi-tion to the regular sample, snubbers which failed the pre-vious functional test shall be retested during the next test period.
If a spare snubber has been installed in place of a failed snubber, then both the failed snubber (if it is repaired and installed in another position) and the spare snubber shall be retested. Test results of these snubbers may not be included in the resampling."
Comment A snubber functional test failure is a violation of Vermont Yankee's present Technical Specifications and, as a result, would require PORC review as well as NRC notification. The subsequent LER specifies that certain corrective action has been, or will be, taken and depending on the mode of func-tional test failure may include functional testing during the next test period in order to determine if service re-lated or generic problems exist with the snubber. The Tech. Specs. also require that in the event of a functional test failure, an additional 107 of the snubbers are removed for testing, efforts would be made to select snubbers in similar locations and operating conditions in an attempt to determine any possible failure trends. Vermont Yankee feels that this approach meets the intent of the proposed Tech.
Specs. and that any additional arbitrary snubber removal and testing is not defensible due to ALARA considerations.
3)
Your proposed Tech. Spec. 4.7.9.c requires that for snubbers found inoperable as a result of functional testing... "an engineering evaluation shall be performed on the components l
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VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission April 7, 1981 Page 3 which are supported by the snubber (s). The purpose of this evaluation shall be to determine if the components supported by the snubber (s) were adversely affected by the inoperability of the snubber (s) in order to ensure that the supported component remains capable of meeting the designed service."
Comment Vermont Yankee's 50 safety class snubbers serve as seismic supports only. Therefore, an engineering evaluation is re-quired only if (1) during the period of time during which the snubber may have been inoperable, a seismic event oc-curred, or, (2) the snubber fails to move during the func-tional test which would have restricted thermal movement of the component to which the snubber was att' ached.
The shock suppressor maintenance procedure will be revised to reflect the requirements for an engineering evaluation in the two instances described above prior to the next functional tests.
4)
Proposed Tech. Spec. Section 4.7.9f Snubber Service Life Monitoring requires, "A record of the service life of each snubber, the date at which the designated service life com-mences and the installation and maintenance records on which the designated service life is based shall be main-tained as required by Specification 6.10.2.1.
Concurrent with the first inservice visual inspection and at least once per 18 months thereafter, the installation and maintenance records for each snubber listed in Tables 3.7-4a and 3.7-4b shall be reviewed to verify that the in-dicated service life has not been exceeded or will not be exceeded prior to the next scheduled snubber service life review.
If the indicated service life will be exceeded prior to the next scheduled snubber service life review, the snubber service life shall be reevaluated or the snubber shall be replaced or reconditioned so as to extend its service life i
beyond the date of the next scheduled service life review.
This reevaluation, replacement or reconditioning shall be indicated in the records."
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VERMONT YANKEE NUCLEAR POWER CORPORATION United States Nuclear Regulatory Commission April 7, 1981 Page 3 Comment Vermont Yankee's present snubber surveillance program re-quires retention of maintenance records for all snubber testing and repairs. Vermont Yankee's maintenance pro-gram requires periodic review of these records in order to determine any failure trends which would establish criteria for determining equipment service life. We feel that this program complies with the intent of the proposed Tech. Spacs. and that no further changes are necessary.
It is the opinion of Vermont Yankee that the Technical Specifica-tions, operation, and maintenance procedures presently in effect are appropriate and sufficient in providing the required assurance of snubber operability and reliability. We will continue to evaluate suggested Technical Specification proposals and surveillance testing methods and make changes whenever such changes will result in improved and safer plant operation.
We note with great interest that there is no mention of resetting snubbers based on snubber fluid viscosity changes due to elevated am-bient temperatures. As documented in various NRC Inspection Reports, particularly between 1977 and 1979, Vermont Yankee has incorporated this into the program. All snubbers located in a high temperature en-vironment were removed and calibration as a result.
It is our feeling that this is an important aspect of demonstrating snubber operability that should be a part of all licensees programs.
We believe that you will find our conclusions appropriately re-sponsive to your proposals. In the event you should desire further discussion of this matter, please do not nestitate to contact us.
Very truly yours, Will am F. Co way Vice President and Manager of Operations l
WFC/jh
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