ML16138A758
| ML16138A758 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/08/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML16138A757 | List: |
| References | |
| NUDOCS 9304160162 | |
| Download: ML16138A758 (3) | |
Text
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,UNITED STATES 0
NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.199 TO FACILITY OPERATING LICENSE DPR-38 AMENDMENT NO.199 TO FACILITY OPERATING LICENSE DPR-47 AND AMENDMENT NO.196 TO FACILITY OPERATING LICENSE DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS 1. 2. AND 3 DOCKET NOS. 50-269, 50-270, AND 50-287
1.0 INTRODUCTION
By letter dated December 8, 1992, Duke Power Company (the licensee) submitted a request for changes to the Oconee Nuclear Station, Units 1, 2, and 3 Technical Specifications (TS).
The requested changes would (1) extend the frequency of the Reactor Protection System (RPS) instrument channel tests in Table 4.1-1 from monthly to every 45 days on a staggered test basis, (2) add the definition of "staggered test basis" to TS Section 1.5, and (3) remove the time limitation in Table 3.5.1-1 on placing one RPS channel in bypass and one channel in the tripped condition. Also, the Bases would be revised to be consistent with the above changes.
The technical justification for the proposed changes was provided in Topical Report BAW-10167, Supplement 1, "Justification for Increasing the Reactor Trip System On-Line Test Intervals," and BAW-10167, Supplement 2, "Justification for Increasing the Reactor Trip System On-Line Test Intervals - Additional Information on Allowed Outage Times."
Safety evaluations of this report and its supplements were performed by the NRC staff, and the staff's evaluation reports and recommendations were included in the approved version of the topical report, BAW-10167A, submitted to the NRC on July 17, 1992.
2.0 EVALUATION 2.1 Instrument Drift In its safety evaluation of BAW-10167, Supplement 1, the staff recommended that each licensee confirm that it has reviewed drift information for each RPS instrument channel over a period of two to three years and determined that setpoint drift over the extended surveillance test interval would not exceed the value allowed by its setpoint methodology. Records of these data and calculations should be maintained onsite for future NRC audits. In its amendment request, the Oconee licensee confirmed that it has reviewed drift information for each RPS instrument channel and determined that drift occurring over the 180-day test interval would not cause the setpoint value to 9304160162 930408 PDR ADOCK 05000269 P
-2 exceed the allowable value for that channel.
The staff, therefore, finds the rate of instrument drift is within acceptable limits.
2.2 Definition of "Staggered Test Basis" The revised surveillance test intervals in TS Table 4.1-1, "Instrument Surveillance Requirements," have been changed to "45 days on a staggered test basis."
This requires the performance of the channel test of one of the four RPS channels every 45 days, so that all four channels have been tested in a 180-day period. The licensee proposes to add the definition of "staggered test basis" as TS 1.5.7. The staff finds the proposed definition to be acceptable.
2.3 TS Table 4.1-1 "Instrument Surveillance Requirements" Currently, RPS instrument channel tests are required to be performed monthly.
The analyses provided in BAW-10167A justify performing the RPS instrument channel tests on a 45-day staggered test basis. The NRC staff has reviewed the analyses provided in BAW-10167A and concluded in its Safety Evaluation Report that the topical report was acceptable for justifying the proposed extensions of the surveillance test intervals to 45 days on a staggered test basis. Therefore, the staff finds the proposed revisions to TS Table 4.1-1 acceptable.
2.4 Allowable Outage Times of RPS Channels The current TS (Table 3.5.1-1) allow one of the four RPS channels to be placed in bypass and one channel to be placed in trip, leaving an effective one out of two trip logic, for a maximum of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The analyses provided in BAW 10167A justify the proposed removal of this time restriction.
The NRC staff has reviewed the risk analyses and additional information included in BAW-10167A and finds that an indefinite bypass of an inoperable instrument string, with one channel already in the tripped condition, will not significantly reduce the reliability of the reactor trip system to trip on demand or reduce the protection against spurious trips. Therefore, the staff concludes that the proposed revisions to TS Table 3.5.1-1, allowing an indefinite repair time for one inoperable channel, are acceptable. The staff expects, however, that the licensee will give high priority to the repair of a bypassed channel.
2.5 Bases The Bases for TS 3.5.1 have been revised to be consistent with the changes to TS Table 3.5.1-1. The Bases for TS 4.1 have been updated to include a reference to BAW-10167A.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the South Carolina State official was notified of the proposed issuance of the amendments. The State official had no comments.
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4.0 ENVIRONMENTAL CONSIDERATION
The amendments change surveillance requirements. The NRC staff has determined 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 occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (58 FR 12259 dated March 3, 1993).
Accordingly, the amendments meet 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 the amendments.
5.0 CONCLUSION
The Commission has 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, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor: S. S. Kirslis Date:
April 8, 1993