ML20056H081

Informs of Changes to ECCS EM Required by 10CFR50.46(a)(3)(ii)

ML20056H081
Person / Time
Site:	Catawba
Issue date:	08/30/1993
From:	Rehn D DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9309080198
Download: ML20056H081 (2)

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Duke hmer Compa? D L Ron Catawba kdear Generanon [xportment nce 14estdent 4DJ ConcordRoad (Sc3gyj.3395 orf,ce ,

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! DUKEPOWER August 30, 1993 l i

U. S. Nuclear Regulatory Commission ATTN: Document Control Desk i Washington, DC 20555

Subject:

Catawba Nuclear Station Docke. 'los. 50-413/50-414 l i

10 CT R i ~ 46 Reporting for ECCS Evaluation Model Changes I

10 CFR 50.46(a)(3)(ii) requires reporting of changes to or errors in ECCS 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 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 Kay Nicholson at (803) 831-3237.

Very truly yours, 1

D. L. Rehn KEN /5046.93 Attachment xc: S. D. Ebneter Regional Administrator, Region Il R. E. Martin, ONRR R. J. Freudenberger  :

Senior Resident Inspector I

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-l Attachment j SBLOCA Am1vses The 1985 Westinghouse CCCS EM analyses apply to all fuel types in the Catawba cores. The analyses shown in the Catawba FSAR are for a case in which a 1304 F PCT is calculated. As l shown in Table 15-39, EM changes previously reported to the NRC could result in an increase in )

this value by up to 136'F. Per Reference 1, there are no additiont.1 changes to report. Therefore. -l the resulting Catawba PCF remains 1440 F. j l 1 LBLOCA Annivses for Wectinohnuse OFA Fuel The 1981 Westinghouse ECCS EM with B ASH analyses apply to the Westinghouse OFA fuel m ~

the Catawba cores. The analyses shown in the Catawba FSAR are for a case in which a 1704 F i PCT is calculated. As shown in Table 15-35, EM changes previously reported to the NRC could result in an increase in this value by up to 238'F for Unit I and 250*F for Unit 2. Per Reference 1, _

there are two additional changes to report. First, conection of the metal type (stainless steel vs. I carbon steel clad with stainless steel) in the structural heat transfer model in the WREFLOOD-INTERIM computer code is estimated to result in a 25*F credit. Second, correction of a 65 psi 3 underestimation of the fuel md intemal pressure is estimated to result in a 2 F penalty. Therefore. l the resulting Catawba LBLOCA PCT for Westinghouse OFA is 1704 + 238 - 25 + 2 = 1919 F for l Unit I and 1704 + 250 - 25 + 2 = 1931*F for Unit 2.

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LBLOCA Analyses for BWFC Mark-BW Fuel The BWFC analyses described in topical report BAW-10174 apply to the BWFC Mark-BW fuel in the Catawba cores. The analyses shown in the Catawba FS AR are for a case in which a 1945*F PCT is calculated, as shown in Table 15-52. Per Reference 2, there is one additional change to report. Consideration of seismically induced steam generator tube crushing occuning coincident with a LBLOCA is conservatively deemed to result in additional plugging of no more than 5% of the tubes. BWFC estimates a penalty of no more than 40 F for this effect. Therefore, the resulting Catawba LBLOCA PCT for BWFC Mark-BW fuel is 1945 + 40 = 1985"F.

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