ML20149K080
| ML20149K080 | |
| Person / Time | |
|---|---|
| Site: | Callaway  |
| Issue date: | 02/12/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20149K075 | List: |
| References | |
| NUDOCS 8802230349 | |
| Download: ML20149K080 (2) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR RFCULATION RELATED TO AMENDMENT NO. J3 TO FACILITY OPERATING LICENSE NO. NPF-30 UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT 1 DOCKET NO. 5TN 50-483
1.0 INTRODUCTION
By letter dated September 11, 1987, Union Electric Company (the licensee) submitted a request for changes to the tec.inical specifications for Callaway to increase the isolation time for the mini-purge isolation valves from 3 to 5 seconds.
2.0 EVALUATION The staff has reviewoo the licensee's request. The licensee's requested closure time still meets the Appendix A (within 5 seconds) guidelines of Standard Review Plan Section 6.2.4, Extending the closure time will, however, increase the radiological consequences of a LOCA during purging by a slight amcunt.
The licensee estimates this increase to be less than 2% of the doses currently estimated at the Exclusion Area Boundary (EAB) and much less than 1% at the Low Population Zone Boundary (LPZ). The staff agrees with the licensee that the increment is small.
The small increment in purge dose combined with the doses projected by the staff in its SER dated October 1981 for the EAB (106 Rem thyroid and 2.2 Rem whole body) or the LPZ (70 Rem thyroid and 0.83 Rem whole body) will not alter the staff's previous ccnclu-sian that the doses meet the guidelines of 10 CFR Part 100.
Consequently, with respect to the incremental dose, the staff finds the requested change acceptable.
The licensee also addressed the ability of the isolation valves to function against the post-LOCA environment. As indicated, the mini-purge was demon-strated to be able to close against the maximum LOCA containment pressure.
Consequently, the increase in closure time has no impact on the valves' ability to close because they have been demonstrated to withstand the worst Case.
Finally, the effect on containment backpressure was examined. Because the release through the valves prior to closure is small ccmpared to that within containment, the raini-purge valve closure times have negligible effect on the ECCS backpressure.
Based on the above, the staff finds the requested change in the isolation time for the mini-purge valves acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or changes the surveillance requirements. Although the amendment could increase the amount of radioactive effluent to the environment in the event of certain accidents, as discussed above such increase would be very small. The staff has 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 Comission has previously issued a proposed finding that this amendment involves no significant hazards considera-tion and there has been no public coninent on such finding. Accordingly, this amendment meets the eligibility criteria fc,r categorical exclusion set forth in 10CFR551.22(c)(9).
Pursuant to 10 CFR 51.22(b), no environmental impact state-ment or environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
The staff 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; and (2) such activities will be conducted in compliance with the Comission's regulations and the issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
Thomas W. Alexion, POIII-3 Dated:
February 12, 1988 m