ML030980630
| ML030980630 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 03/27/2003 |
| From: | Atkinson D Energy Northwest |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| G02-03-052 | |
| Download: ML030980630 (2) | |
Text
ENWERGY NORTH WEST P0. Box 968
- Richland, Washington 99352-0968 March 27, 2003 G02-03-052 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555
Subject:
COLUMBIA GENERATING STATION, DOCKET NO. 50-397 10 CFR 50.46 REPORT OF CHANGES IN CYCLE 17 ECCS EVALUATION MODEL
References:
- 1) Letter, G02-02-138, dated September 3, 2002, RL Webring (Energy Northwest) to NRC, "Request for Amendment to Technical Specification 4.2.1 and 5.6.5.b"
- 3) Letter, GI2-02-181, dated October 31, 2002, Brian Benney (NRC), to Energy Northwest, "Summary of Meeting Held on October 2, 2002, Regarding Transition to New Fuel"
Dear Sir or Madam:
The purpose of this letter-is to-report, in -accordance-with the requirements of 10_CFR 50.46(a)(3)(ii), the impact of non-significant changes in the Emergency Core Cooling System (ECCS) evaluation methodology used in the determination of the peak cladding temperature predicted for Columbia Generating Station operation during cycle 17.
Columbia Generating Station is currently in cycle 16. The next refueling outage is scheduled to begin in May 2003 and end in June 2003. Reference 1 submitted a request for amendment to the Columbia Generating Station Technical Specifications that would support the transition from Westinghouse SVEA-96 to Framatome ANP ATRIUM-10 reload fuel. This amendment request identified Reference 2 as the methodology that would be used to perform the Emergency Core Cooling System evaluations for operation during cycle 17.
1,0
10 CFR 50.46 REPORT OF CHANGES IN CYCLE 17 ECCS EVALUATION MODEL Page 2 At a meeting held with the Staff on October 2, 2002, to discuss the transition plan to the new fuel (Reference 3) it was noted that several changes to the approved ECCS methodology (Reference 2) would be made to support the cycle 17 analyses. Energy Northwest committed to reporting these methodology changes to the Staff within 30 days of plant restart.
These methodology changes and their impact are summarized below.
The methodology described in the NRC approved topical report noted by Reference 2 was applied in the ECCS analyses for Columbia Generating Station Cycle 17 reload analyses. The topical report describes several validation calculations and sample problems used to justify the methodology. The RELAX computer code described in the topical report was modified for use in performing the Columbia Generating Station analyses.
A description of the modifications and their impact on the calculated peak cladding temperature (PCT) is summarized below.
These methodology modifications were-explicitly-used in -the calculation of the ATRIUM-10 licensing basis PCT (1404 IF for two recirculation loop operation) during cycle 17.
Methodology ATRIUM-10 PCT Modification Impact (A 0F)
A unit conversion factor change in RELAX, 0
MW to BTU The upper limit on the void fraction in the RELAX slip model logic is increased to
-11 improve numerical stability If you have any questions or require additional information regarding this matter, please contact Ms. CL Perino, Licensing Manager at (509) 377-2075.
Respectfully, DK Atkinson Vice President, Technical Services Mail Drop PE08 cc: EW Merschoff - NRC RIV RN Sherman - BPA/1399 TC Poindexter - Winston & Strawn BJ Benney - NRC NRR DG Holland - NRC NRR NRC Resident Inspector - 988C