ML20237A767
| ML20237A767 | |
| Person / Time | |
|---|---|
| Site: | Byron, Braidwood, 05000000 |
| Issue date: | 12/08/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20237A762 | List: |
| References | |
| NUDOCS 8712150242 | |
| Download: ML20237A767 (2) | |
Text
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!s.R MQy o,j UNITED STATES NUCLEAR REGULATORY COMMISSION 7,,
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT N0.13 TO FACILITY OPERATING LICENSE N0. NPF-37, AMENDPENT N0.13 TO FACILITY OPERATING LICENSE NO. NPF-66 AND AMENDMENT N0. 3 TO FACILITY OPERATING LICENSE NO. 72 COMMONWEALTH EDISON COMPANY BYRON STATION, UNITS 1 AND 2 BRAIDWOOD STATION, UNIT 1 DOCKET N05. STN 50-454, STN 50-455 AND STN 50-456
1.0 INTRODUCTION
By letter dated September 39, 1987Property "Letter" (as page type) with input value ""September 39, 1987" contains a sequence that could not be interpreted against an available match matrix for date components." contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process. Commonwealth Edison company (the licensee) submitted a request for revision of the Technical Specifications for Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2.
The proposeo revision would delete the reactor trip on turbine trip below 30 percent power.
By letter dated October 30, 1987 the licensee provided additional clarifying information.
2.0 EVALUATION The Byron and Braidweod units are designed to accommodate a 50 percent load rejection. Thus, a reactor trip on turbine trip should not be required below 50 percent power. The proposed change will delete the reactor trip on turbine trip below 30 percent power, which is within the design capability of the units.
This modification should reduce the number of unnecessary reactor trips during startup, shutdown and low power operations.
Reducing the number of unnecessary reactor trips will reduce the transients imposed on the plant and the challenges to safety systems and increase plant availability.
Many other Westinghouse plants across the nation have instituted a similar modification.
The reactor trip on turbine trip is an anticipatory trip and no credit is taken for this trip in the FSAR Chapter 15 accident analyses. Thus, revising the setpoint for this trip to 30 percent power will have no impact on the accident analysis.
The staff asked the licensee to address NUREG-0737, Item II.K.3.10, the concern regarding the potential increase in the probability of a small l
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, break loss-of-coolant accident (LOCA) resulting from a stuck-open pressurizer power operated relief valve (PORV) when this modification is implemented.
By letter dated October 30, 1987, the licensee addressed this concern.
The letter presents the results of a best-estinate analytical study which show that no additional pressurizer PORV challenges are expected due to implementation of the modification that deletes reactor trip on turbine trip below 30 percent power. Therefore, the staff concludes that the proposed changes are acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve a change in the installation or use of the facilities' components located within the restricted areas as defined in 10 CFR Part 20.
The staff has determined that these 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 these amendments involve no significant hazards consideration and there has been no public comment on such finding. Accordingly, these 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 assess-ment need be prepared in connection with the issuance of these amendments.
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 these amendnents will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
L. Olshan Dated: December 8, 1987
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