ML20057F329
| ML20057F329 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 10/06/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20057F327 | List: |
| References | |
| NUDOCS 9310150146 | |
| Download: ML20057F329 (3) | |
Text
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S NUCLEAR REGULATORY COMMISSION 5-WASHINGTON, D.C. 20T6-0001 Qm )
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 69 TO FACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 48 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 July 31, 1992, as supplemented January 22 and July 27, 1993, Georgia Power Company, et al. (the licensee) proposed license amendments to change the Technical Specifications (TS) for Vogtle Electric Generating Plant (Vogtle), Units 1 and 2.
The proposed changes add TS 3/4.7.1.6 which would provide a limiting condition for operation (LCO) and surveillance requirements (SR) for the main feedwater (MFW) isolation system. On September 28, 1992, the staff issued NUREG-1431, Revision 0, the improved standard technical specifications (STS) for Westinghouse plants.
Subsequently, the licensee, by letter dated January 22, 1993, updated the proposed TS to be consistent with the wording of the improved STS which included a TS for the MFW isolation system. The proposed specification requires that the MFW isolation and regulating valves, and their associated bypass valves be operable or isolated when the reactor is in MODES 1 or 2.
An associated BASES section (B 3/4.7.1.6) was also included in the proposed revision.
The ACTION statements, as proposed in the January 22, 1993, submittal, were inconsistent with the APPLICABILITY in that they required the plant to be in MODE 4 if the system was inoperable for a given length of time. Therefore, by letter dated July 27, 1993, the licensee revised the ACTION statements to require the plant to be in MODE 3 whenever the LCO was not met for the specified times.
This would put the plant in a mode where the LCO would no longer be applicable.
The July 27','1993, letter provided a minor change to improve consistency with the improved STS and did not change NRC's proposed finding of no significant hazards consideration determination.
2.0 EVALUATION A main feedwater isolation valve (MFIV) and an associated main feedwater isolation bypass valve (BFIV) are provided for each of the MFW lines to the four steam generators.
Each of these lines contain an upstream MFW regulating valve (MFRV) and an associated MFW bypass regulating valve (BFRV). The MFW line to each steam generator can be isolated by the closure of either an MTIV or MFRV and its associated bypass valve.
These valves provide redundant 9310150146 931006 DR ADOCK 05000424 PDR
. isolation for each MFW line.
All of these valves receive automatic isolation signals from the engineered safety features actuation system (ESFAS) which is included in the instrumentation section of the plant TS.
The safety-related function of these valves is to provide isolation of MFW flow to the steam generators in the event of certain accidents or transients.
The current Vogtle TS do not have a specification for these valves except as they relate to the operability of the ESFAS. Because these valves are a part of the primary success path for mitigation of an accident, they should be specifically included in the plant TS. The proposed TS change would correct this oversight.
The proposed TS requires the valves to be OPERABLE in MODES 1 and 2, except when the MFIV, MFRV, or associated bypass valve is closed and deactivated.
The modes are acceptable because they are in agreement with the existing Vogtle TS for the MFW isolation function of the ESFAS.
In these modes, there is significant energy in the reactor coolant system and the steam generators requiring the valves to remain open for adequate heat dissipation from the primary side.
In the remaining modes, there is less energy and since the MFW system is not used for startup or shutdown, the valves are closed.
Startup and shutdown are performed using the auxiliary feedwater (AFW) system. When the valves are closed, they are performing their safety function and, therefore, the APPLICABILITY exception that the isolation system be considered OPERABLE when an inoperable valve is closed, is acceptable. This is the same applicability as in the Westinghouse improved STS for plants similar to the Vogtle design.
ACTION Statement a. in the proposed TS provides that if one MFIV, MFRV, or associated bypass valve is inoperable in one or more MFW lines, operation may continue provided each inoperable valve is restored to OPERABLE status or closed within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />.
Otherwise, the plant must be in HOT STANDBY (MODE 3) within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
This is acceptable because of the redundancy provided in each line such that the isolation function is still available.
Also, this action is consistent with the action taken for an inoperable main steam isolation valve (MSIV) in the Vogtle TS.
ACTION Statement b., as proposed, provides that with no isolation system (each system consisting of an MFIV and its associated bypass valve or an MFRV and its associated bypass valve) OPERABLE in any one feedwater line, restore at least one system in each line to OPERABLE status within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or be in HOT STANDBY (MODE 3) within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. This ACTION statement is consistent I
with the Vogtle TS for two inoperable MSIVs in one steam line. These times are considered acceptable based on operating experience and the low probability of an event requiring main feedwater isolation during the time period.
The proposed surveillance requirements (SR) for the main feedwater isolation system are consistent with the accident analyses in Chapter 15 of the Vogtle Final Safety Analysis Report (FSAR). The proposed SR are, therefore, acceptable. The proposed exception for entry into MODE 2 is also acceptable because, according to existing procedures, the licensee normally performs this SR after entry into MODE 2.
Until the test, the valves are maintained closed and the steam generators are fed by the AFW system.
A '
) The proposed change includes all related requirements of NUREG-1431, Revision 0.
Consequently, the NRC staff has concluded that this proposed i
change satisfies the Commission's Final Policy Statement on Technical Specification Improvement (58 FR 39132).
Based on its evaluation as described above, the staff concludes that the proposed TS change is consistent with the accident analyses in the FSAR and with related Vogtle TS for the MSIVs and the ESFAS. Moreover, the proposed 3
change will enhance safety by limiting plant operation with the MFW system inoperable. The staff, therefore, concludes that the proposed change is t
acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Georgia State official I
was notified of the proposed issuance of the amendments. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change regt.irements with respect to installation or use of a facility component locatc) within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements.
The NRC staff has determined that the amendments involve no significant increase in the amounts. nd no significant change in the types, of any effluents that may be releasea offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously issued a i
proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (58 FR 16859 dated March 31,1993). 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 or, the considerations discussed above, that:
(1) there is reasonable assura nce that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, l
and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
4 i
Principal Contributors:
W. LeFave D. Starkey D. Hood i
Date:
October 6, 1993 j
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