ML20211F365
| ML20211F365 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/19/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20211F353 | List: |
| References | |
| NUDOCS 9908300313 | |
| Download: ML20211F365 (3) | |
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.114 AND 102 TO FACILITY OPERATING LICENSE NOS. NPF-76 AND NPF-80 L
STP NUCLEAR OPERATING COMPANY. ET AL.
DOCKET NOS. 50-498 AND 50-499 SOUTH TEXAS PROJECT. UNITS 1 AND 2
1.0 INTRODUCTION
By application dated March 22,1999, as supplemented by letter dated July 15,1999, STP Nuclear Operating Company, et al. (the licensee), requested changes to the South Texas Project (STP), Units 1 and 2, Technical Specifications (TSs). The proposed changes would revise TS 3/4.7.1.6," Atmospheric Steam Relief Valves," and add a new TS for atmospheric steam relief valve instrumentation, to ensure that the automatic feature of the steam generator power-operated relief valves (i.e., the atmospheric steam relief valves) remains operable during Modes 1 and 2.
The July 15,1999, supplement provided revised TS pages and clarifying information that was within the scope of the original Federa/ Register notice and did not change the staff's initial proposed no significant hazards consideration determination.
2.0 BACKGROUND
The licensee proposed a change to the TSs governing the steam generator power-operated relief valves for its STP plants that would require the steam generator power-operated relief valves to be operable during operating Modes 1 thro' ugh 3, and in Mode 4 when steam generators are being used to remove decay heat. This revision would permit the licensee to credit steam generator power-operated relief valve operation in Modes 1 and 2 small-break i
loss-of-coolant accident (SBLOCA) licensing analyses.
3.0 EVALUATION 3.1 Steam Generator Power-Ocerated Reiief Valve Features in its submittal, the licensee provided information describing the steam generator power-operated relief valves and their operation. In descr,bing the steam generator power-operated relief valves, the licensee identified that the valves, their construction, motive power, and controls are all safety grade. Each steam generator power-operated relief valve has a self-contained motive operator with its own reservoir of fluid, such that the valve can be cycled indefinitely without exhausting the motive fluid supply. Electrical devices associated with the steam generator power-operated relief valve motive power and cor.trols are supplied with ht h G
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. Class 1E power. The steam generator power-operated relief valves open and close at pressure setpoints programmed into their controllers from the control room. The valves can be opened or closed from the control room. The staff concludes that the steam generator power-operated relief valves and their functional controls are safety grade.
3.2 TS Chanaes The proposed change requests a revision to TS 3/4.7.1.6, " Atmospheric Steam Relief Valves."
The proposed change also requests a new TS, TS 3/4.3.5," Atmospheric Steam Relief Valve Instrumentation."
The new instrumentation TS ensures the automatic control feature of the steam generator power-operated relief valve remains operable during Modes 1 and 2. This will allow mitigation of the consequences of an SBLOCA and will meet the requirements of 10 CFR 50.46. The proposed change adds an associated surveillance to the new instrumentation TS that requires that a channel calibration on the steam generator power-operated relief valve, which includes verification of automatic actuation at the 1225 psig setpoint with uncertainties, be performed every 18 months. This surveillance intervalis consistent with assumed uncertainties in the safety analysis to ensure the steam generator power operated relief valves will perform their intended function. In addition, by letter dated July 15,1999, the licensee proposed additional surveillan:es on each steam generator power-operated relief valve automatic actuation channel consisting of a channel check at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and an analog channel operational test at least once every 18 months. These additional surveillances will provide a high degree of confidence of the operational availability of the automatic controls during reactor operation.
The new instrumentation specification allows manual operation of the steam generator power-operated relief valve (s) in Mode 2 if being used to maintain the secondary side pressure at or below an indicated steam generator pressure of 1225 psig.' This condition is required during plant startup to place a steam load on the plant to control primary plant temperature. The action statements for an inoperable automatic actuation control channel (s) are consistent with those for the manual actuation control channels except that only Mode 3 is required to be achieved if the allowed outage times cannot be met.
The requirement for manual controls for steam generator power-operated relief valves to be operable in Modes 1 through 4 are moved from TS 3.7.1.6 to the new instrumentation TS. The limiting condition for operation, applicability, and action statements for manual controls remain unchanged from that currently found in TS 3.7.1.6.
TS 3.7.1.6 is revised to delete man'ual controls as a limiting condition for operation for the steam generator power-operated relief valves. The limiting condition for manual controls is moved to the new instrumentation TS. Surveillance Requirement (SR) 4.7.1.6 is revised to reflect that valve operation must be verified by operation using both automatic and manual controls following any cold shutdown of 30 days or longer or following any refueling shutdown.
The wording "any cold shutdown of 30 days or longer following any refueling shutdown" is rearranged to clarify that SR 4.7.1.6 should be performed following any refueling shutdown regardless of duration.
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. The licensee has also proposed Bases for the new and revised TSs. The proposed Bases are consistent with the proposed TSs at.d indicate that the proposed TSs are consistent with uncertainties assumed in the safety analyses.
Based on the above, the staff finds that the proposed TSs and Bases are adequate to ensure that the licensing basis SBLOCA analyses assumptions are met.
3.3 Summary Based on the safety-grade design of the STP steam generator power-operated relief valves, as governed by the proposed TSs and their Bases, and the stated consistency of the steam generator power-operated relief valves and their controls with the uncertainties assumed in the STP licensing safety analyses, the staff finds that the proposed TSs and Bases are acceptable and also finds that the licensee may credit the performance of the steam generator power-operated relief valves in the STP SBLOCA licensing analyses for Modes 1 and 2.
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Texas State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located 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 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 (64 FR 19565). 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.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that (1) there is j
reasonable assurance 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, 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.
Principal Contributors: F. Orr T. Alexion Date: August 19, 1999 r
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