ML20071N746
| ML20071N746 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 07/28/1994 |
| From: | Rehn D DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9408080194 | |
| Download: ML20071N746 (2) | |
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Duke 1%wer Company DLRuy Catauha Nurlear Generatoon Department Oce nesident
'4800 Concord Road (803)&113205 Office York, SC 2:1745 (803)&113426Far l
DUKEPOWER July 28,1994 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555
Subject:
Catawba Nuclear Station Docket Nos. 50-413/50-414 10 CFR 50.46 Reporting for ECCS Evaluation Model Changes 10 CFR 50.4G(a)(3)(ii) requires reporting of changes to or errors in ECCS i
evaluation model (EM), or in the application of the EM, which affect the LOCA peak clad temperature (PCT). The attachment contains the information for small
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break LOCA (SBLOCA), large break LOCA (LBLOCA) for Westinghouse OFA fuel, and LBLOCA for Mark-BW fuel.
Any questions concerning this submittal may be directed to H. Jackson Lee at 704-382-7565.
Very truly yours, b
D. L. Rehn KEN /5046.94 Attachment xc:
S. D. Ebneter Regional Administrator, Region 11 R. E. Martin, ONRR R. J. Freudenberger Senior Resident Inspector 9408080194 940728 PDR ADOCK 05000413 P
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CATAWBA NUCLEAR STATION DOCKET NOS. 50-413 AND 50-414 e
10 CFR 50.4G REPORTING FOR ECCS EVALUATION MODEL CHANGES SBLOCA Analyses l
The 19x5 Westinghouse ECCS EN! analyses apply to all fuel types in the Cataw ba cores. The analyses wiuch will be show n in the October I,1994 Catawba FS AR include a case in which a 1264*F PCT is calculated. As shown in Reference 4. EM changes previously reported to the NRC could result in an increase in this value by up so 1375F. Per Reference I, there is one additional change to repon. a benefit due error corrections in the LUCIFER code. This is a code used to generate compment databases for both the large and small break LOCA analyses. Ec benefit is 16'F for small break analyses. Derefore, the resulting Cataw ba PCT is 1264 + 137 - 16 =
1385 F LBLOCA Analyses for Westinchouse OFA Fuel De 1981 Westmphouse ECCS EM with B ASli analyses apply to the Westinghouse OFA fuelin the Catawba cores. De analyses which will be shown in the October 1,1994 Catawba FSAR include a case in which a 1945 F PCT is calculated. As shown in Table 15-35 for the previous analysis. EM changes previously reponed to the NRC could result in an increase of up to 215*F for Unit I and 227 F for Unit 2. Per Reference 1. the reanalysis which will be included in the FS AR update climinated the need to account separately for all but three of these changes. These are 1) a 1(X FF penalty due to potential nonconservatisms in the assumed axial power distribution.
- 2) a 25*F benefit due to correction of the metal type (stainless steel vs. carbon steel clad with stainless steel) in the structural heat transfer model in the WREFLOOD-INTERIM computer code, and 3) an 8 F (Unit 1) or 20 F (Unit 2) penalty for seismically induced steam generator tube
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crushing occurring coincident with a LBLOCA. Berefore, there remain a total of 100 25 + 8 =
83*F (Unit 1) or 100 - 25 + 20 = 95 F (Unit 2) of previously reponed changes which are relevant to the new analysis. In addition, per Reference 1. the LUCIFER change reponed above for small break LOCA analysis results in a 6 F benefit for large break LOCA. Derefore, the resulting Catawba LBLOCA PCT for Westinghouse OFA is 1945 + 83 6 = 2022'F for Unit I and 1945 +
95 6 = 2034'F for Unit 2.
LBLOCA Analyses for BWFC Mark-BW Fuel
%c BWFC analyses described in topical repon BAW 10174 apply to the BWFC Mark-BW fuel in the Catawba cores. The analyses shown in the Catawba FSAR are for a case in which a 1945cF PCT is calculated, as shown in Table 15-52. As shown in this table. EM changes previously
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reponed to the NRC could result in an increase in this value by up to 40 F. Per Reference 2, there is one additional change to report, applicable only to Catawba Unit 2 and only as long as it contains fuel originally fabricated for the Tmjan nuclear plant. His fuel has 1) a slightly lower UO density. 2) a higher enrichment, and 3) axial blankets. BWFC estimates a PCT penalty of no 2
more than 23'F for these design features. In addition. Duke Power has applied. as will be reponed via 10 CFR 50.59, a penalty of WF for postulated increases, from 10% to 18% in the level of tube plugging in the most plugged steam generator Reference 5 contains the basis for not treating this change as "significant" per 10 CFR 50.46. Herefore the resulting Catawba LBLOCA PCT for BWFC Mark BW fuelis 1945 + 40 + 64 = 2049 F for Unit I and 1945 + 40 + 23 + 64 =
l 2072 F for Unit 2.
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