ML20058E153
| ML20058E153 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 11/01/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20058E146 | List: |
| References | |
| NUDOCS 9011070052 | |
| Download: ML20058E153 (3) | |
Text
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UNITED STATES
t NUCLEAR REGULATORY COMMISSION
,j w ASHWGTON, D. C. 20555
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SAFETY EVALVATION BY-THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 53 -
TO FACILITY OPERATING LICENSE NO. NPF-62 ILLINOIS POWER COMPANY, ET AL.
CLINTON POWER STATION, UNIT NO. 1 DOCKET NO. 50-461
1.0 INTRODUCTION
By letter dated' November. 20, 1989, Illinois Power Company, et al. (the licensee),proposedfourchangestotheTechnicalSpecifications(TS)for
-Clinton Power Station. The third proposed change revises the value for the
. Secondary Containment minimum free volume specified in TS 5.2.3.
The fourth proposed change removes the provision of TS 4.0.2 that limits the combined time interval for three consecuthe surveillances to less than 3.25 times the specified interval. Guidance on this proposed change to TS was provided to
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.all power reactor licensees and applicants by NRC Generic Letter 89-14, dated August'21, 1989.
2.0 EVALUATION Section 5.0 of the Clinton TS provides data on certain design features for the-Clinton Power Station. Section 5.2.3 provides a description of portions of the plant' encompassed by the Secondary Containment and the value for the
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minimum free volume. During a Quality Assurance audit of the Clinton TS, it was noted that the'value for secondary containment minimum free volume specified in TS 5.2.3 was different than the value in the Updated Safety Analysis Report (USAR).
Investigation determined that the current value in the TS was an Linitial. estimate and that the USAR value was the correct one and it had been used in all applicable analyses discussed in the USAR. The change will make.
the TS correct and consistent with the value in the USAR and is acceptable to the staff.
Specification 4.0.2 includes the )rovision that allows a surveillance interval to ba-extended by 25 percent of tie 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 main-tenance activities. Specification 4.0.2 further limits the a11cwance 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. The purpose of this provision is to assure that surveillances are not extended repeatedly as an operational convenience to provide an overall increase in the surveillance interval.
9011070002 901101 PDR ADOCK 05000461-P PNV
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 extend-ing refueling surveillances because the risk to safety is low in contrast 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 concluded that Specification 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 surveillance interval with a maximum allowable. extension 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 changes to
-the TS for Clinton Power Station are acceptable.
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3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a requirement with respect to the instal-lation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 or a change to a surveillance requirement. The staff has determined that the amendment involves no significant increase in the l 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 this amendment involves no significant hazards consideration and there has been no public coment on such finding. Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forthin10CFR51.22(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 this amendment..
4.0 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 Comission's regulations and the issuance of this amendment will not be inimical to the comon defense and security or to the health.and safety of the p'ublic.
Principal Contributors:. Thomas G. Dunning, NRR John B. Hickman, NRR Dated:
November 1, 1990 I