ML20065N961
| ML20065N961 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 12/07/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20065N958 | List: |
| References | |
| NUDOCS 9012130029 | |
| Download: ML20065N961 (3) | |
Text
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NUCLEAR REGULATORY COMMISSION ti 8
WASHINGTON, D. C. 20b55 i
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SAFETY. EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 57 TO FACILITY OPERATING LICENSE NO. DPR-80 1
AND AMENDMENT NO. 56 TO FACILITY OPERATING LICENSE NO. DPR-82 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON NUCLEAR POWER PLANT, UNIT NOS. 1 AND 2 DOCKET NO. 50-275 AND 50-323
1.0 INTRODUCTION
By letter dated November 16, 1989, Pacific Gas and Electric Company (PG&E orthelicensee)re Specifications (TS) quested amendments to the combined Technical appended to Facility Operating License Nos. DPR-80 and DPR-82 for the Diablo Canyon Power Plant (DCPP), Unit Nos. I and 2, i
respectively. These amendments remove the provision of the previous Technical Specification 4.0.2 that limits the combined time interval for three consecutive surveillances to less than 3.25 times the specified interval. Guidance'on this proposed change to TS 4.0.2 was provided to-l all power reactor. licensees and applicants by Generic Letter 89-14, dated August 21, 1989. The revised TS maintain, as before, the provision l
allowing a surveillance interval to be extended by 25 ' percent of the specified time interval.
2.0 EVALUATION 1
Both the previous and the revised TS 4.0.2 contain a provision that allows a surveillance interval to be extended by 25 percent of the specified time interval. This extension provides flexibility for..
l scheduling the performance of surveillances and to permit consideration of plant operat_ing. conditions that may not be suitable for conducting a-surveillance at the specified time interval. Such operating conditions include transient plant operation or ongoing surveillance or maintenance activities.
In addition, the previous version of TS 4.0.2 further-limited the allowance for extending surveillance intervals by requiring that the combined time interval for any three consecutive surveillances not exceed 3.25 times the specified time interval. This provision has been deleted in the TS revision approved by these amendments. The purpose of this provision was to assure that surveillances are not extended repeatedly as an operational convenience to provide an overall increase in the surveillance interval.
9012130029 901207 PDR ADOCK 05000275 P
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Experience has shown that the 18-month surveillance interval, with the provision to extend it by 25 percent, is usually sufficient to accommodate normal variations in the length of a fuel cycle. However, the NRC staff has routinely granted requests for one-time exceptions to the _3.25 limit on extending: refueling surveillances because the risk to safety is low inicontrast to the alternative of a forced shutdown to perform these surveillances. Therefore, the 3.25 limitation on extending surveillances has not been a practical = limit on the use of the 25-percent allowance for extending surveillances that are performed on a refueling outage basis.
Extending surveillance intervals during plant operation can also result in a benefit to safety when a scheduled surveillance.is due at a time that is not suitable for conducting the surveillance. This may occur when transient plant operating conditions exist or when safety systems are out of service for maintenance or other surveillance activities.
In-such cases, the benefit to safety of extending a surveillance interval would exceed any safety benefit derived by limiting the use of the 25-percent allowance to extend a surveillance. Furthermore, there is the administrative burden associated with tracking the use of the 25-percent allowance to ensure compliance with the 3,25 limit.
In view of these findings, the staff has concluded that TS 4.0.2 should be changed to remove the 3.25 limit for all surveillances because its removal will have an overall positive effect on safety. The guidance provided in Generic Letter 89 included the following change to this specification and removes the 3.25 limit on three consecutive surveillances with the following statement:
"4.0.2 Each Surveillance. Requirement shall be performed within the specified surveillance interval with a maximum allowable extension not-to exceed 25 percent of the specified surveillance interval."
In addition, the Basis of this specification was u change and noted that it-is not the intent of the.pdated to reflect this allowance for extending surveillance intervals that it be used. repeatedly merely as an operational convenience to extend surveillance intervals beyond that specified.
The licensee has proposed changes-to TS.4.0.2 that are consistent with the guidance provided in Generic Letter.89-14, as noted above.
Therefore, the staff finds that the above changes to the Combined TecMical Specifications for-Diablo Canyon Units 1.and 2 are acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
These amendments involve changes with respect to th'e installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20, or changes in a surveillance requirement. The staff has determined that these amendments involve no significant increase in the i
amounts, and no significant change in the types, of any effluents that
nwy 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 these amendments involve no significant hazards consideration and there has been no public comE,ent on s
such finding.
Accordingly, these amendments meet the eligibilit criteria for categorical exclusion set forth.in 10 CFR 51.22(c)(y).
9 Pursuant to 10 CFR 51.22(b) no environmental impact statement.or environmental assessnent need be prepared in connection with the issuance of this amendment.
4.0 CONCLUSION
We have 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, and (2) such activities will be conducted in compliance with the Commission's regulations, and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
H. Rood Dated:
December 7,1990 i
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