ML20199L358
| ML20199L358 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 01/20/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20199L353 | List: |
| References | |
| NUDOCS 9901270204 | |
| Download: ML20199L358 (2) | |
Text
pP Uouq UNITED STATES g
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NUCLEAR REGULATORY COMMISSION 2
WASHINGTON. D.C. Saana mi i"
SAFETY EVALUATICN BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.120 TO FACILITY OPERATING LICENSE NO. NPF-62 ILLINOIS POWER COMPANY CLINTON POWER STATION. UNIT 1 DOCKET NO. 50-461
1.0 INTRODUCTION
By letter dated July 31,1998, Illinois Power Company (IP), the licensee for Clinton Power Station, requested a change to the Clinton Power Station Technical Specifications on diesel generator (DG) surveillances associated with fast starting of the machines. These surveillances (SR 3.8.1.7, SR 3.8.1.12, SR 3.8.1.15, and SR 3.8.1.20) require that the DG start from a dead-stop condition and accelerate to specified voltage and frequency limits within 12 seconds. The limits of the voltage and frequency tolerance specified in the current surveillances are more representative of steady state conditions than transient conditions, iP has therefore requested that the surveillances be modified to reflect the transient nature of the DG voltage and frequency et the 12-second period following a fast start from the dead-stop condition. These types of chenges have been approved by the staff as generic changes to be incorporated into the next revision of the Improved Standard Technical Specifications (ISTS).
2.0 EVALUATION IP proposes to change Clinton Technical Specification Section 3.8.1 by revising the acceptance criteria of surveillances SR 3.8.1.7, SR 3.8.1.12, SR 3.8.1.15, and SR 3.8.1.20 consistent with the generic changes to be incorporated into the next revision of the ISTS. Currently, these surveillances in the Clinton Technical Specifications require that j
each DG achieve a voltage 2 3870 V and s 4580 V and frequency 2 58.8 Hz and s 61.2 Hz within 12 seconds. IP is proposing that the surveillances be revised to require that each DG (a) achieve a voltage 2 3870 V and a frequency 2 58.8 Hz within 12 seconds, and (b) subsequently achieve a steady state voltage 2 3870 V and s 4580 V and frequency 2 58.8 Hz and s 61.2 Hz.
In their letter dated July 31,1998, IP has stated that when a test is performed that does not result in tying the DG to the bus, a momentary voltage or frequency overshoot (and/or subsequent undershoot) can occur because no loads are being tied to the DG. IP indicates 9901270204 990120 PDR ADOCK 05000461 P
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2 that loading tends to minimize the overshoot, whereas the unloaded overshoot might momentarily exceed the specified limit (s) within the 12-second time limit. The NRC staff agrees. The voltage and frequency tolerance band currently specified in the subject surveillances are more appropriate for steady state limits than transient limits, as evidenced by the recommendations in NRC Regulatory Guide 1.9 which allow a larger band for transient voltage and frequency deviations. The changes IP has proposed appropriately specify the original voltage and frequency tolerance band as steady state values while, in the transient region within 12 seconds, they specify only minimum values. In addition, the LOOP and the LOCA/ LOOP load sequencing tests required by SR 3.8.1.11 and SR 3.8.1.19 in the Clinton Technical Specifications will continue to verify (on an 18-month frequency) the capability of the Clinton DGs to provide power at a voltage and frequency adequate to start and operate the safety loads.
Based on the foregoing considerations, the staff concludes that the proposed amendment is acceptable.
3.0 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.
4.0 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 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 amendment involves no significant 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 environrnental assessment need be prepared in connection with the issuance of the amendment.
5.0 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, (2) such activities will be conducted in compliance with the Commission's regu'atixis, 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: J. Lazevnick Date: January 20, 1999