ML17306A876
| ML17306A876 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 08/05/1992 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17306A875 | List: |
| References | |
| NUDOCS 9208130045 | |
| Download: ML17306A876 (6) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON. D.C. 20555 9208130045 9gpapg PDR ADOC< pgpppgp8 p
PDR SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.
63 TO FACILITY OPERATING LICENSE NO.
NPF-41 AMENDMENT NO.
49 TO FACILITY OPERATING LICENSE NO.
NPF-51 ND AMENDMENT NO.
36 TO FACILITY OPERATING LICENSE NO. NPF-74 ARIZONA PUBLIC SERVICE COMPANY ET AL.
PALO VERDE NUCLEAR GENERATING STATION UNIT NOS.
1 2
AND 3 DOCKET NOS.
STN 50-528 STN 50-529 AND STN 50-530
1.0 INTRODUCTION
On June 25,
- 1990, the staff issued Generic Letter 90-06, "Resolution Of Generic Issue 70,
'Power-Operated Relief Valve and Block Valve Reliability,'nd Generic Issue 94, 'Additional Low-Temperature Overpressure Protection for Light-Water Reactors,'ursuant to 10 CFR 50.54(f)."
The generic letter represented the technical resolution of the above mentioned generic issues.
Generic Issue 70, "Power-Operated Relief Valve and Block Valve Reliability,"
involves the evaluation of the reliability of power-operated relief valves (PORVs) and block valves and their safety significance in PWR plants.
The generic letter discussed how PORVs are increasingly being relied on to perform safety-related functions and the corresponding need to improve the reliability of both PORVs and their associated block valves.
Proposed staff positions and improvements to the plant's technical specifications were recommended to be implemented at all affected facilities.
However, this issue is not applicable to Palo Verde Nuclear Generating Station (PVNGS) because the plant does not have PORVs.
Generic Issue 94, "Additional Low-Temperature Overpressure Protection for Light-Water Reactors,"
addressed concerns with the implementation of the requirements set forth in the resolution of Unresolved Safety Issue (USI) A-26, "Reactor Vessel Pressure Transient Protection (Overpressure Protection)."
The generic letter discussed the continuing occurrence of overpressure events and the need to further restrict the allowed outage time for a low-temperature overpressure protection channel in operating modes 4, 5, and 6.
This issue is only applicable to Westinghouse and Combustion Engineering facilities.
By letters dated June 7,
- 1991, November 20,
- 1991, and April 13, 1992, Arizona Public Service Company (APS) proposed changes to the Palo Verde Nuclear Generating Station technical specifications in response to Generic Letter.90-06.
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2.0 ALUATION FOR GENERIC ISSUE 94 The actions proposed by the NRC staff to improve the availability of the low-temperature overpressure protection (LTOP) system represents a substantial increase in the overall protection of the public health and safety and a
determination has been made that the attendant costs are justified in view of this increased protection.
The technical findings and the regulatory analysis related to Generic Issue 94 are discussed in NUREG-1326, "Regulatory Analysis for the Resolution of Generic Issue 94, Additional Low-Temperature Overpressure Protection for Light-Water Reactors."
The proposed changes to the PVNGS technical specifications included in the licensee's letters of June 7,
- 1991, and April 13,
- 1992, are consistent with that proposed in the staff's generic letter.
For example, one of the proposed modifications to the technical specifications involves plant operation in modes 5 and 6 with an inoperable LTOP channel.
At PVNGS, LTOP is achieved using the shutdown cooling system (SCS) relief valves.
The licensee has adopted the staff position that operation under such conditions be limited to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> before restoring the SCS relief valve to an operable status.
The staff has reviewed the licensee's proposed modifications to PVNGS technical specifications.
Since the proposed modifications are consistent with the staff's position previously stated in the generic letter and justified in the above mentioned regulatory analysis, the staff finds the proposed modifications to be acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Arizona State official was notified of the proposed issuance of the amendment.
The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes 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 considera-
- tion, and there has been no public comment on such finding (56 FR 43802).
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.
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- 5. 0 CONCLUSION The Commission has 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 operation in the proposed
- manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment:will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
D. Pickett
.Date:
August 5, 1992
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