ML20059J520
| ML20059J520 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/12/1994 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20059J513 | List: |
| References | |
| NUDOCS 9402010056 | |
| Download: ML20059J520 (3) | |
Text
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pa atcuqk UNITED ST ATES j.,Y*'fj NUCLEAR REGULATORY COMMISSION t
WASHINGTON, D.C. 20566 4 001
- ...+
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.g TO FACILITY OPERATING LICENSE NO. NPF-57 PHILADELPHIA ELECTRIC COMPANY LIMERICK GENERATING STATION. UNIT 1 DOCKET NO. 50-352
1.0 INTRODUCTION
By letter dated August 3, 1993, the Philadelphia Electric Company (the licensee) submitted a request for changes to the Limerick Generating Station, Unit 1, Technical Specifications (TS). The requested changes would remove certain remote shutdown system control valves and primary containment isolation valves from TS Tables 3.3.7.4-1, " Remote Shutdown Instrumentation and Controls," and 3.6.3-1, " Primary Containment Isolation Valves," as a result of eliminating the steam condensing mode of the Residual Heat Removal (RHR) system.
2.0 BACKGROUND
The steam condensing mode is used to condense steam while the reactor is isolated from the main condenser and vessel level is maintained by the Reactor Core Isolation Cooling (RCIC) system. The heat removed in the RHR heat exchangers is transported to the ultimate heat sink by the RHR service water system. The steam condensing mode of the RHR system, addressed in Chapter 5 of the Updated Final Safety Analysis Report does not take credit for this mode to mitigate an accident. The RHR system steam condensing mode is a non-safety-related function of RHR. However, the RHR components associated with this mode are safety-related for pressure and structural integrity.
Currently, power is removed from the steam admission valves to the RHR heat exchangers and the valves locked in the closed position, which renders the mode inoperable. The licensee continues to perform routine preventive maintenance and surveillance testing on various components associated with the steam condensing mode due to TS requirements.
3.0 EVALUATION i
During the upcoming Unit 1 fifth refueling outage the licensee has planned a modification to remove from service the remainder of the steam condensing mode components, thereby, eliminating further required testing or preventive maintenance on these components.
The proposed modification will result in downgrading the portion of RHR system piping left in place, from safety-related to non-safety-related. The valves 9402010056 940132 i
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. to be removed from service or left in place, are those designed only for the RHR syatem steam condensing mode. The piping left in place will no longer be a part af the primary containment pressure boundary and will be isolated from the RHR and HPCI systems. The modification will not affect the operation or safety-related function of the RHR or High Pressure Coolant Injection (HPCI) systems. The valves or piping that is removed will have flanges and penetration caps installed which will become part of the primary containment boundary.
Periodic tests for leakage will be performed on the flanges and penetration caps in accordance with the primary containment Integrated Leak Rate Testing (ILRT) Program; they are not subject to Type B (local leak rate) testing because they are fully welded in place.
The requested change involves the deletion of the following valves from TS Table 3.3.7.4-1, " Remote Shutdown Instrumentation and Controls" and TS Table 3.6.3-1, " Primary Containment Isolation Valves".
RHR heat exchanger discharge line to Reactor Core Isolation Cooling (RCIC) system valve: HV-51-1F026A Steam supply line to RHR heat exchanger valve: HV-51-1F052A Steam supply line to RHR heat exchanger warm-up bypass valve:
HV-51-153A RHR system steam condensing mode relief valve discharge:
PSV-51-101A (B), PSV-51-1F055A (B), PSV-51-1F097 These valves are not containment isolation valves and will be left in place.
The piping associated with valves HV-51-1F052A and HV-51-153A will be removed and steel plates will be welded at the ends. This will isolate the RHR system from the HPCI system.
Valve HV-51-1F026A will be left in place and de-engerized in the closed position.
The PSVs will be physically removed and replaced by blank flanges. The primary containment penetration X-240 associated with valve PSV-51-1F097 will be capped and will become part of the primary containment structure. The remaining portion of the piping between primary containment penetration X-240 and the flanges replacing the PSVs will not be affected and will continue to meet the original design requirements.
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The RHR vacuum relief suction inboard Primary Containment Isolation Valve i
(PCIV) HV-51-130 and the associated piping leading up to the outboard PCIV HV-51-131 will be removed. The HV-51-131 valve will be abandoned in place and 1
de-energized in the closed position. The primary containment penetration X-225 associated with valve HV-51-131 will be capped, as well as the piping
)
upstream of the valve.
i All safety-related flanges and pipe caps installed on the safety-related i
portions of piping for the RHR and HPCI systems, and the primary containment penetration caps will be fabricated and installed in accordance with the i
j
4 o original design requirements. All piping and components that remain operable will continue to meet the original design requirements.
The staff has evaluated tne deletion of the identified remote shutdown system control valves and primary containment isolation valves from the Technical Specifications and concludes that they do not degrade the ability of RHR, and HPCI systems to respond to an accident.
Basically, only valves specifically used for the RHR system steam condensing mode will be abar.doned in place or removed from the plant.
In addition, the other modes of RHR (e.g., low Pressure Coolant Injection and Shutdown Cooling) will not be affected by the modification.
Therefore, the staff finds the deletion of certain remote shutdown system control valves and PCIVs from the TS, and the proposed modification to the steam condensing mode of RHR acceptable.
3.0 STATE CONSULTATION
In accordance with the Comission's regulations, the Pennsylvania State official was notified of the proposed issuance of the amendment. The State official had no coments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves 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 Comission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public coment on such finding (58 FR 50969). Accordingly, the amendment meets 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 amendment.
5.0 CONCLUSION
The Comission has 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, (2) such activities will be conducted in compliance with the Comission's regulations, and (3) the issuance of the amendment will not be inimical to the comon defense and security or to the health and safety of the public.
Principal Contributor:
J. Zimerman Date: January 12, 1994