ML15112A992
| ML15112A992 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 01/28/1981 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML15112A991 | List: |
| References | |
| NUDOCS 8102200817 | |
| Download: ML15112A992 (3) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 91 TO FACILITY OPERATING LICENSE NO. DPR-38 AMENDMENT NO. 91 TO FACILITY OPERATING LICENSE NO. DPR-47 AMENDMENT NO. 88 TO FACILITY OPERATING LICENSE NO. DPR-55 DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS IOS. 1, 2 AND 3 DOCKETS NOS. 50-269, 50-270 AND 50-287 Introduction By letter dated December 29, 1980, the Duke Power Company (the licenseeor DPC) submitted proposed changes to the Station's common Technical Specifications (TSs) that extend the surveillance interval for certain surveillance requirements from an annual to an 18-month nominal cycle.
Background
The three Oconee Units are in a transition from a nominal 12-month fuel cycle to a nominal 18-month fuel cycle. The licensee wishes to avoid unnecessary shutdown outages to perform certain surveillances that would be required on an annual basis if the surveillance intervals were not extended.
Evaluation The licensee proposed surveillance interval changes in four TSs:
4.0 Surveillance Standards, 4.1 Operational Safety Review, 4.4 Reactor Building, and 4.8 Main Steam Stop Valves.
Each proposal is individually evaluated by TS Section number as follows:
4.0 Surveillance Standards This TS is an overall surveillance requirement for all safety-related equipment and structures. The only proposed change is to add the term "Refueling Outage" and define it as a maximum allowable interval between surveillances of 22 months 15 days.
This definition is based on a nominal interval of 18 months plus 25%.
This definition is consistent with NUREG-0103, Revision 3, the Standard Technical Specifications (STS) for Babcock and Wilcox (B&W) reactors and is therefore acceptable.
8102200%11
-2 4.1 Operational Safety Review The portions of this TS affected by the December 29, 1980, change request relate to instrument channel calibration for protection system instruments, control system instruments and engineered safety feature instruments, and to the minimum test frequencies for relief valves and safety valves.
The proposal is to extend the calibration or test frequencies from annual to each refueling outage which is a nominal 18-month interval plus 25%. The instrument surveillance limits, as proposed, are acceptable as they are con sistent with Table 1.2 and Section 4.0.2 of the STS. The proposed test frequencies for the relief and safety valves are acceptable as they are in, agreement with Table IWV 3510-1 of Section XI of the ASME Boiler and Pressure Vessel Code.
4.4 Reactor Building The requested change regarding the Reactor Building is to extend the visual examination interval of the accessible interior and exterior surfaces from annual to each refueling interval.
This examination is part of the 10 CFR 50 - Appendix J, primary reactor containment leakage testing requirements.
Section V.A of Appendix J requires an interval of three examinations within a 10-year period. We find an examination at each refueling interval to be acceptable as it will provide more than three examinations within a 10-year period.
4.8 Main Steam Stop Valves The main steam stop valves become isolation valves in the unlikely event of a concurrent loss-of-coolant accident and a steam generator feedwater header rupture. The closure times of the valves, which determine the rate of reac tivity insertion following a main steam line break accident, are not being changed by these license amendments, nor is the currently specified leak rate.
The proposed change affects only the closure time test interval; the licensee proposes to extend it from annual to each refueling. Each refueling could result in an interval of 18 months plus 25% or 22 months 15 days. Appendix J of 10 CFR 50, which governs isolation valves, requires a minimum test fre quency of two years.
We conclude that a test frequency of each refueling is acceptable as it is less than the two-year frequency of Appendix J.
Environmental Consideration We have determined that the amendments do not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made this determination, we have further concluded that the amendments involve an action which is insignificant from the standpoint of environmental impact and, pursuant to 10 CFR §51.5(d)(4),
that an environmental impact statement, or negative declaratibn and environ mental impact appraisal need not be prepared in connection with the issuance of these amendments.
-3 Conclusion We have concluded, based on the considerations discussed above, thatp (1
because the amendments do not involve a significant increase in the probability or consequences of accidents previously considered and do not involve a signi ficant decrease in a safety margin, the amendments do not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be condu cted in compliance with the Commission's regulations andthe issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Dated:
January 28, 1981