ML20029B358
| ML20029B358 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 03/04/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20029B357 | List: |
| References | |
| NUDOCS 9103070095 | |
| Download: ML20029B358 (3) | |
Text
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UNITED STATES l
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NUCLEAR REGULATORY COMMISSION l
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I SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 21 AND 11 TO FACILITY OPERATING LICENSE NOS. NPF-76 AND NPF-80 HOUSTON LIGHTING & POWER COMPANY CITY PUBLIC SERVICE BOARD OF SAN ANTONIO CENTRAL POWER AND LIGHT COMPANY CITY OF AUSTIN, TEXAS DOCKET NOS. 50-498 AND 50-499, SOUTH TEXAS PROJECT, UNITS 1 AND 2 INTRODUCTION By application dated September 5,1990 (ST-HL-AE-3561), Houston Lighting & Power Company, et. al., (the licensee) requested changes to the Technical Specifica-tions (Appendix A to Facility Operating License Nos. NPF-76 and NPF-80) for the South Texas Project, Units 1 and 2.
The proposed changes would remove the provision of Section 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 the Technical Specifications (TS) was provided to all power reactor licensees and applicants -by Generic Letter 89-14, dated August 21, 1989.
EVALUATIOg TS 4.0.2 includes the provision that allows a surveillance interval to be extended by 25 percent of.the specified time interval.
This extension provides flexibility for scheduling the performance of surveillances and to permit consideration of plant operating 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.
TS 4.0.2 further limits the allowance for extending surveillance intervals by requiring that the combined time interval for any three consecutive surveillances.not exceed 3.25 times the specifir1 time i nte r_ val.
The purpose of this provision is to assure that survei ances are I
not extended repeatedly as an operational convenience to provide tn overall increase in the surveillance interval.
Experience has shown that the 18-month surveillance interval, with the provision l
to extend it by 25 percent, is usually sufficient to accommodate normal variations in the length of a fuel cycle.
However, the NRC staf f has routinely granted requests for one-time exceptions to the 3.25 limit on extending refueling surveillances because the risk to safety is low in contrast to the l
alternative of a forced shutdown to perform these surveillances.
Therefore, 9103070095 910304 PDR ADOCK 05000498
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 en a refueling outage basis.
Extending surveillar.ce 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 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 89-14 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 survelliance interval with a maximum allowabic ex-tension not to exceed 25 percent of the specified surveillance interval."
In addition, the Bases of this specification were updated to reflect this change and noted that it is not the intent of the 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 Specification 4.0.2 that are consistent with the guidance provided in Generic letter 89-14, as noted above.
On the basis of its review of this matter, the staff finds that the above change to the TS for the South Texas Project, Units 1 and 2, are acceptable.
ENVIRONMENTAL CONSIDERATION The amendments involve a change in a requirement with respect to the installation or use of a facility component located within the restricted crea as defined in 10 CFR Part 20 and changes in surveillance requirements.
The staff has determined that the amendments involve no significant increase in the amounts, and no signi-ficant change in the types, of any affluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposures.
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.
Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR Section 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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CONCLUSION The staff 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, and (2) such activities will be conducted in ' compliance with the Commission's regulations and the issuance of the amendments will not be inimical'to the common defense and security or to the health and safety of the public. -The _ staff, therefore, concludes that the proposed changes are acceptable.
. Date:' Me.rch 4.-1991-Principal Contributors:- T. Dunning G. Dick-F j
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