ML20198D860
| ML20198D860 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 12/14/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20198D852 | List: |
| References | |
| NUDOCS 9812230256 | |
| Download: ML20198D860 (3) | |
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UNITED STARS V
NUCLEAR REGULATORY COMMISSION U
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.118TO FACILITY OPERATING LICENSE NO. NPF-62 lLLINOIS POWER COMPANY CLINTON POWER STATION. UNIT 1 DOCKET NO. 50-461 2
1.0 INTRODUCTION
Technical Specification (TS) 3.8.1 of the Clinton Power Station contains Surveillance Requirements (SRs) that require the plant emergency diesel generators (EDGs) to be electrically loaded to a specific load during testing. SR 3.8.1.3 provides the requirements for
- the 60-minute load-run test, and requires the EDGs to be loaded to greater than or equal to 100% of their continuous ratings. SR 3.8.1.10 provides the requirements for the full-load rejection test, and requires the EDGs to be capable of rejecting a load greater than or equal to 100% of their continuous ratings. SR 3.8.1.14 provides the requirements for the endurance and margin test, and requires the EDGs to be loaded to greater than or equal to 110% of their continuous ratings for at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> out of the total 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of continuous operation, and to greater than 100% of their continuous ratings for the remaining portion of the 24-hour period (i.e.,22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br />). SR ' O.1.15 demonstrates that the EDGs can restart from a hot condition (such as when the EDGs could be demanded to respond to an accident immediately following completion of normal surveillance testing) by verifying that each EDG starts and achieves
- required voltage and frequency within a specified time. This SR contains a Note that requires
< the SR to be performed within a specified time after the EDGs have operated at a load greater than or equal to 100% of their continuous ratings for at least one hour, in July 1993, the staff issued RG 1.9 Rev. 3 which integrated the guidance previously addressed in RG 1.9 Rev. 2, RG 1.108 Rev.1, and GL 84-15, " Proposed Staff Actions to improve and Maintain Diesel Generator Reliability." By letter dated August 17,1998, Illinois Power (licensee) requested approval of the Tecnnical Specification changes to SR 3.8.1.3, SR 3.8.1.10, SR 3.8.1.14, and SR 3.8.1.15 to partially reduce the load at which the standby EDGs are required to be tested.
2.0 EVALUATION The 60-minute run test (SR 3.8.1.3), the full-load rejection test (SR 3.8.1.10), and the 24-hour run test (SR 3.8.1.14) are currently required to be conducted at loads greater than or equal to the continuous ratings of the EDGs Except fu a required portion of SR 3.8.1.14 (as described below), the licensee has proposed to revise these tests to allow them to be conducted with the
- EDGs loaded to greater than or equal to 90% of their continuous ratings.
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With regard to a 60-minute load-run test (SR 3.8.1.3), this test currently requires each EDG to L
be capable of synchronizing and accepting greater than or equal to the equivalent of the maximum expected accident loads (continuous rating). The licensee has proposed that this surveillance be performed with an EDG loaded to equal or greater than 90% of its continuous J
rating instead at a load greater than or equal to 100% of the EDG continuous rating. This is consistent with the guidance provided in Section 2.2.2 of RG 1.9 Rev. 3 which states that the load-run test be demonstrated at 90 to 100 percent of the continuous rating of the EDG for an interval of not less than 60 minutes.
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l With regard to full load rejection test requirements (SR 3.8.1.10), this test currently requires l
each EDG to be capable of rejecting a load greater than or equal to the 100 percent of its 4
continuous rating. The licensee has proposed that this surveillance be performed with an EDG load equal to or greater than 90% of its continuous rating. This is consistent with the guidance provided in Section 2.2.8 of RG 1.9 Rev. 3 which states that the full load rejection test be l
demonstrated at a load equal to 90 to 100 percent of the continuous rating of the EDG.
With regard to the 24-hour run test (SR 3.8.1.14), this test currently requires each EDG to be operated at a load greater than or equal to 110% of its continuous rating for a period greater than or equal to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and at 100% of its continuous rating for the remaining 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br />.
Recently, the licensee discovered that after properly accounting for instrument accuracy, which required an additional margin to be incorporated into the maximum and minimum load values specified in the test procedures, the EDGs cannot be operated and loaded to greater than or equal to 110% of design load rating without exceeding the short-term ratings of the machines.
l Exceeding the short-term rating of an EDG can cause damage, and depending on the length of l
time that the sbmt-term rating is exceeded, can require significant inspection to be performed to assess any di > age. The EDG manufacturers typically specify load levels for EDGs, which if exceeded for certain periods of time, can require the EDGs to undergo additionalinspection and maintenance. This problem would be resolved by the proposed change to the Technical Specifications, since reducing the minimum required load band within each EDG could be operated without the F.DG's short-term rating being exceeded. The intent of the recommended guidance on RG 1.9 Rev. 3 for these tests is to reduce the load levels at which the EDGs are l
routinely tested, while still ensuring that the EDGs are sufficiently challenged to verify their operability. The licensee has proposed that each EDG be operated at a load greator than or i
equal to 105% of its continuous rating for greater than or equal to 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> and at 90% of its continuous rating for the remaining 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br />. Section 2.2.9 of RG 1.9 Rev. 3 states that the l
endurance and margin test is to be demonstrated for an interval of not less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, of which 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> are at a load equal to 105 to 110 percent of the continuous rating of the EDGs, l
and 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> are at a load equal to 90 to 100 percent of its continuous rating. The proposed change is consistent with the RG except that the licensee has proposed only to require that the EDGs be loaded to a load level greater than or equal to 90 percent or 105 percent of their continuous rating, with no upper limit specified. The staff believes that reducing the minimum required level meets this intent without the need to specify an upper limit. Moreover, the proposed Technical Specification changes (i.e., with no maximum limit specified) are consistent with the format of the licensee's current Technical Specifications, wherein no maximum limit is specified.
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3 With regard to the requirements of SR 3.8.1.15, associated Note 1 sets forth the condition which requires the surveillance to be performed within 5 minutes of shutting down the EDG after it has operated for greater than or equal to one hour at a load greater than or equal to 100% ofits continuous rating. The proposed Note would require the surveillance to be performed within 5 minutes of shutting down the EDG after the EDG has operated for greater than or equal 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> at a load greater than or equal to 90% of its continuous rating. However, whereas the current version of Note 1 requires the EDG to be previously loaded to the required l
load level for greater than or equal to one hour for performance of SR 3.8.1.15, the proposed l
version of Note 1 would require the EDG to be previously loaded to the new, reduced load level j
for at least 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> for performance of SR 3.8.1.15. The required load period of 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> is consistent with the guidance of RG 1.9, Rev. 3.
3.0 FINDING 4
Based on the above, the staff concludes that the proposed changes to SR 3.8.1.3, SR 3.8.1.10, SR 3.8.1.14, and SR 3.8.1.15 will permit the licensee to perform tests at reduced levels while still ensuring that the EDGs are adequately challenged at operating temperatures to confirm operability and the changes are consistent with the guidance of RG 1.9 Rev. 3 and are, therefore, acceptable.
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Illinois State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
This 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 or changes a surveillance requirement. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no sign.'ficant 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 amendment involves no signifNnt hazards consideration and there has been no public comment on such finding (63 FR 53949). 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.
6.0 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 l.
operation in the proposed manner, (2) such activities will tie conducted in compliance with the i
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.
1 Principal Contributor: N. Trehan Date: DecemDer 14, 1998
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