ML20217P043
| ML20217P043 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 04/29/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20217P037 | List: |
| References | |
| NUDOCS 9805060047 | |
| Download: ML20217P043 (2) | |
Text
1
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t UNITED STATES g
j NUCLEAR REGULATORY COMMISSION E
WASHINGTON, D.C. 20066-0001 os,...../
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REOULATION RELATED TO AMENDMENT NO.166 TO FACILITY OPERATING LICENSE NO. DPR-72 ELORIDA POWER CORPORATION 1
CRYSTAL RIVER UNIT 3 l
DOCKET NO. 50-302
1.0 INTRODUCTION
By letter dated October 4,1997, Florida Power Corporation provided plans to modify the reactor building fan cooler (RBFC) electrical logic and requested an amendment to the Crystal River Unit 3 Operating License that would authorize changes to Technical Specification Bases and the Final Safety Analysis Report (FSAR). The licensee determined that the proposed changes would constitute an Unresolved Safety Question and thus require staff approval prior to implementation.
During a loss-of-coolant accident (LOCA), reactor building cooling is provided by the reactor f
building spray system and the RBFC system. The reactor building fan cooler (RBFC) system has three fan coolers (AHF-1A, AHF-1B, and AHF-1C). Currently either AHF-1 A or AHF-1B is l
automatically started in response to a reactor building isolation and cooling (RBIC) signal and the RBFC that is not started is configured as an automatic backup in case the first RBFC does l
not start. Presently AHF-1C is not used in response to an RBIC signal. The proposed l
modifications would allow AHF-1C to be substituted for either AHF-1A or AHF-1B as the lead or l
backup RBFC.
2.0 EVALUATION AHF-1C was originally designed as a swing fan to be used as a substitute or supplement during normal cooling and was administratively removed from service because of potential excessive diesel loading concems and service water limitations. The licensee has proposed a modification to the electrical logic to allow AHF-1C to be substituted for either AHF-1 A or AHF-
- 18. In order to prevent loading more than one RBFC on an emergency diesel generator and to ensure proper alignment of the RBFCs and the power scurces, the licensee has provided automatic start permissive interlocks, relays, operating procedures, and alarms. The logic would allow any one of the three RBFCs to be selected as the lead RBFC and either of the two l-remaining RBFCs to be selected as the automatic backup in the event of RBIC signal.
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.e The new logic circuit adds a level of complexity to the starting of thc RBFCs because its ' proper operation depends upen additional interlocks, relays, and relay contacts that have been added i
. to provide this new logi. A potential single failure in the logic circuits that could result in no -
RBFCs operating is bounded by the licensee's previous analysis that was performed to
. evaluate failure of the service water system, resulting in no cooling water to the RBFCs. This condition was previously evaluated bnd found acceptable because reactor building cooling can ibe accomplished by the use of both trains of the reactor building spray system. Based on the;
- above evaluation, the staff concludes that the Unresolved Safety Question regarding 'new credible failure modes is bounded by the licensee's previous analysis and the proposed modification continues to provide reasonable assurance that adequate containment cooling would be available when required. Therefore, the staff finds the proposed modification of the:
RBFC electrical logic to be acceptable.
3.0 STATE CONSULTATION
Based upon written notice of the proposed amendment, the Florida State official had no i
comments.
j
4.0 ENVIRONMENTAL CONSIDERATION
S
.The amendment changes requirements with respect to installation or use of a facility
)
component located within the restricted area as defined in 10 CFR Part 20. The U.S. Nuclear Regula6y Commission staff has determined that the amendments involve no significant.
increase in the amounts, and no significant change in the types, of any effluents that may be -
l 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 this amendment involves no significant hazards consideration and there has been no public comment on such finding (63 FR 2423). Accordingly, the amendment meets the eligibility j
criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to.10 CFR 51.22(b),
j no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
5.0 CONCLUSION
Based on its evaluation, the staff concludes that the proposed modifications to the AHF-1C electrical logic are acceptable because new credible failure modes are bounded by a previously approved analysis. The staff, therefore, concludes that the licensee's proposed changes to FSAR and Bases sections of the plant technical specifications are acceptable.
Principal Contributor: Barry S. Marcus
. Dated: April 2g,138
.