ML20078C378
| ML20078C378 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 01/20/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078C366 | List: |
| References | |
| NUDOCS 9501260285 | |
| Download: ML20078C378 (2) | |
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k UNITED STATES NUCLEAR REGULATORY COMMISSION f
WASHINGTON, D.C. 20 4 5 4001
\\*****/ SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 82 TO FACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 60 TO FACILITY OPERATING LICENSE NPF-81 GEORGIA POWER COMPANY. ET AL.
V0GTLE ELECTRIC GENERATING PLANT. UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425
1.0 INTRODUCTION
By letter dated March 31, 1994, Georgia Power Company, et al. (the licensee)
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proposed license amendments to change the Technical Specifications (TS) for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2.
The proposed changes would revise TS Table 3.7-1 by lowering the maximum allowable power 1
range neutron flux high setpoint when one or more main steam safety valves (MSSVs) are inoperable. The proposed changes would also revise the Bases for TS 3/4.7.1.1 to include the Westinghouse algorithm for determining the new setpoint values.
2.0 EVALUATION Westinghouse has determined that the maximum allowable power range neutron flux high setpoints given in TS Table 3.7-1 may not be low enough to prevent a l
secondary side overpressurization during a less of load / turbine trip.
In Nuclear Safety Advisory Letter (NSAL)94-001 dated January 20, 1994, Westinghouse reported their determination that the maximum allowable initial power level is not a linear function of available MSSV relief capacity.
It was further determined that the current TS provisions for reduced reactor power levels with inoperable MSSVs may not preclude the secondary side pressure from exceeding 110% of its design value during a loss of main feedwater transient, particularly at lower power levels. NSAL 94-001 also provided the licensee with an algorithm for determining revised neutron flux high setpoints.
The licensee has calculated new neutron flux high setpoint values using the Westinghouse NASL 94-001 algorithm. The new values were lower than the values in the current TS. Also, the calculated values were further reduced to account for instrument and channel uncertainties. This process resulted in high neutron flux reactor trip setpoint values of 71%, 51%, and 31% of rated thermal oower for a maximum of one, two, and three inoperable MSSVs, respectively, on any operating steam generator.
Current TS values are 87%,
65% and 43% for those same conditions.
The staff has found that the revised algorithm ensures that the maximum power level allowed for operation with inoperable MSSVs is below the heat-removing capability of the operable MSSVs. This ensures that the secondary system 9501260285 950120 PDR ADOCK 05000424 P
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pressure will not exceed 110 percent of its design value.
In addition, the new setpoints are more conservative than the previous setpoints. Therefore, the staff finds that the proposed changes to TS Table 3.7-1 and Bases 3/4.7.1.1 are acceptable.
3.0 STATE CONSULTATION
i In accordance with the Commission's regulations, the Georgia State official was notified of the proposed issuance of the amendments. The State official had no comments.
l 4.0 ENVIROMENTAL CONSIDERATION l
1 The amendments change requirements with respect to installation or use of a 3
facility component located withir, the restricted area as defined in 10 CFR i
Part 20. 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 4
significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the i
amendments involve no significant hazards consideration, and there has been no public comment on such finding (59 FR 37071). 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 1
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
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defense and security or to the health and safety of the public.
l Principal Contributors:
L. Wheeler j
C. Liang 1
Date: January 20, 1995 i
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