ML20196J487
| ML20196J487 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/01/1988 |
| From: | NRC OFFICE OF SPECIAL PROJECTS |
| To: | |
| Shared Package | |
| ML20196J466 | List: |
| References | |
| TAC-00176, TAC-00177, TAC-00178, TAC-176, TAC-177, TAC-178, NUDOCS 8803140344 | |
| Download: ML20196J487 (2) | |
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UNITED STATES p
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SAFETY EVALUATION BY THE OFFICE OF SPECIAL PROJECTS SilPPORTING AMENDMENT NO.146 TO FACILITY OPERATING LICENSE NO. OPR-33 AMENDMENT NO.142 TO FACILITY OPERATING LICENSE NO. OPR-52 AMENOMFNT NO.117 TO FACILITY OPERATING LICENSE NO. OPR-68 TENNESSEE VALLEY AUTHORITY PROWNS FERRY NUCLEAR PLANT, UNITS 1, 2 AND 3 DOCKETS NOS. 50-259, 50-260 AND 50-296
1.0 INTRODUCTION
By letter dated May 15, 1987, Tennessee Valley Authority (the licensee) requested a change tc the Browns Ferry Nuclear Plant, Unit 1, 2 and 3 Technical Specification to delete the requirenent to perform a partial closure test of the main steam isolation valves (MSIVs) denoted in Surveillance Requirement 4.7.D.1.c.
Deletion of the test requirement would allow the partial closure test to be performed quarterly, consistent with the require-ments in Table 4.1.A r'or the Reactor Protection Systen scram on MSIV closure, rather than the twice per week test as currently specified.
2.0 EVALUATION The Technical Specifications for Browns Ferry Nuclear Plant, Unit 1, 2 and 3 currently requires twice-weekly partial closure testing of the MSIVs. The licensee's request to decrease the frequency cf the partial closure test (to quarterly) is offset by an increase in safety. The proposed change would decrease the probability of an inadvertent scram and plant trarsients. Since 1977, the licensee stated that the Browns Ferry Nuclear Power Plant has experienced five scrams attributable to equipment used during this test.
The increase in safety may be partially affected by the decrease in surveillance frequency for the MSIVs. However, this decrease is limited by other quarterly surveillance requirements which not only ensures that the rechanical portion of the MSIV is not stuck but also test the safety controls utilized in closing the MSIVs. The twice-weekly partial closure test only verified the mechanical portion of the valve and ensures that the MSIV is r.ot stuck in the open position. A review of the Browns Ferry Main Steam System traintenarce request indicates that failure of the mechanical portion of the valve has not been a dominant failure moce and MSIV closure has been demonstrated with a high degree of reliability. With deletion of the partial cicsure test requirernent, the current Browns Ferry Technical Specifications still require that MSIVs be tested and closure tine be verified on a cuarterly basis which is in precise accordance with the staff's guidance as specified in the standard Technical Specifications.
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. Additionally, the licensee's request would be censistent with the guidance of NUREG-0737. Item II.K.3.16, for reducing challenges to the relief valve by
.* educing MSIV testing.
Therefore, the staff finds this change to delete the requirement to perform a cartial closure test of twice per week on the MSIVs acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes to requirements with respect to the installation or use of facility corponents located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance requirerents. We have 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 Commission has made a final no significant hazards consideration finding with respect to these amendments. Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFP 51.22(b), no environmental impact statement nor environmental assessment need be prepared in connection with the issuance of these amendments.
4.0 CCNCLUSION We have concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health ano safety of the public will not be endangereo by operation in the proposed manner, and (2) such activities will be conducted in ecmpliance with the Corrission's regulations, and the issuance of the amendments will not be inimical to the ecmmon defense and security nor to the health and safety of the public.
Principal Centributor: John Stang Dated: March 1, 1988
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