ML20138C675
| ML20138C675 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 11/27/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20138C658 | List: |
| References | |
| TAC-57219, NUDOCS 8512130068 | |
| Download: ML20138C675 (2) | |
Text
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NUCLEAR REGULATORY COMMISSION
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 90 TO FACILITY OPERATING LICENSE NO. NPF-3 TOLEDO EDISON COMPANY AND THE CLEVELAND ELECTRIC ILLUMINATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 DOCKET NO. 50-346
1.0 INTRODUCTION AND BACKGROUND
By letter dated August 18, 1983, as modified November 20, 1984, the Toledo Edison Company (licensee) requested that the Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse) Technical Specifications (TSs) be revised to include a special leakage test requirement for the containment purge and exhaust isolation valve penetrations.
The current TSs require that the containment isolation valves be leak tested once for each operating cycle during refueling. We requested that the valves be tested more frequently to determine if excessive degradation of the valve seats has occurred. Specifically, we reconsnended that the valves be tested at three-month intervals or after each use of the purge system with a maximum t
interval not to exceed six months.
2.0 EVALUATION In the November 20, 1984 submittal, the licensee proposed to perfom the special leak testing of the purge valves within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> after each use of the purge system (limited to Modes 5 and 6) or prior to entering Mode 4 from Mode 5, whichever is later. In addition, the special leak testing will be performed after being in Modes 3, 4, 5, or 6 for more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following power operation if the special or Type C leak tests have not been performed within the past six months. The licensee contends that implementing a fixed, six-month special test schedule is not feasible because the test requires access to the annulus area which has a radiation level in excess of 1 R/hr during power operation. Without shutting down the reactor, the test could result in high personnel radiation exposures.
Due to the high radiation levels that may be present in the annulus during and shortly after leaving Modes 1 and 2, we have agreed that the licensee may perform the special leak test (1) after each use of the purge system, and (2) when the plant has been in Modes 3, 4, 5, or 6 for more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and the valves have not been tested in accordance with Appendix J or the special leak test requirements within the past six months. We find this approach acceptable because containment purge isolation valves are normally sealed
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- closed during Modes 1 through 4, and the outboard valve is within the secondary containment annulus. Therefore, the valve seats will not be subject to degradation in Modes 1 through 4 stemming from system use, will be protected from environmental extremes and will be checked following each use of the purge system.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves changes in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes in surveillance requirements. 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 previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding. Accordingly, this 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 this amendment.
4.0 CONCLUSION
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 this amendment will not be inimical to the common t
defense and security or to the health and safety of the public.
Dated: November 27, 1985 The following NRC personnel contributed to this Safety Evaluation:
J. Guo
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