ML18029A740
| ML18029A740 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 07/08/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18029A739 | List: |
| References | |
| NUDOCS 8508020351 | |
| Download: ML18029A740 (4) | |
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UNITEDSTATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO.
118 TO FACILITY OPERATING LICENSE NO.
DPR-33 AMENDMENT NO, 113 TO FACILITY OPERATING LICENSE NO.
DPR-52 AMENDMENT NO.
89 TO FACILITY OPERATING LICENSE NO.
DPR-68 TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT UNITS I 2 AND 3 DOCKET NOS. 50-259, 50-260 AND 50-296
1.0 INTRODUCTION
By letter dated November 19, 1984 (TVA ITS-204) the Tennessee Valley Authority (the licensee or TVA) requested amendments to Facility Operating
'License Nos.
DPR-33, DPR-52 and DPR-68 for the Browns Ferry Nuclear Plant, Units I, 2 and 3.
The amendments would delete requirements associated with the condenser low vacuum scram function.
2.0 DISCUSSION AND EVALUATION The basis for the turbine condenser low vacuum scram is to provide an anticipatory scram to reduce the pressure increase of the reactor vessel caused by a turbine trip on low condenser vacuum.
At greater than 154 psig turbine first stage
- pressure, the turbine trip would also cause a scram.
The low vacuum scram setpoint is selected to intiate a scram before the closure of the turbine stop valves is initiated.
In the accident and transient analyses, (FSAR Chapter 14) no credit is taken for this anticipatory signal; therefore, there will be no decrease in safety margins caused by deletion of this scram.
Additionally, the BWR Standard Technical Specifications contain no requirement for this scram.
The deletion is proposed to preclude plant derating during periods of high condenser back pressure.
These conditions exist primarily during conditions of high river water temperatures.
These conditions have previously caused unit deratings.
These proposed revisions, therefore, will allow an increased power output during conditions of higher than normal condenser back pressure.
Additionally, these proposed revisions will reduce surveillance testing requirements and decrease the probability of an inadvertent scram.
Because no credit is taken for the low condenser vacuum trip in the transient and accident analyses and because turbine trip will also cause reactor trip for first stage pressure greater than 154 psig, we find the proposed deletion of the low condenser vacuum scram to be acceptable.
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- 3. 0 ENVIRONMENTAL CONSIDERATIONS The amendments involve a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The 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.
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.
4.0 CONCLUSION
We have concluded, based on the considerations discussed above, that (I) there is reasonable assurance that the health and safety of the public will not be endangered by operftion in the proposed
- manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of'he public.
Principal Contributor:
W. Hodges Dated:
July 8, 1985