ML20024J350

Forwards Info for Sbloca,Large Break LOCA (LBLOCA) for Westinghouse Ofa Fuel & LBLOCA for Mark-BW Fuel,Per 10CFR50.46

ML20024J350
Person / Time
Site:	McGuire, Mcguire
Issue date:	10/04/1994
From:	Mcmeekin T DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9410140119
Download: ML20024J350 (3)

Text

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-l DukeIbwerCompany T. C Mdftra.

McGuire Nuclear Generation Depanment McePresident i

12700Hagers FerryRoad(MG01W)

, (704)8754800.

Huntersville, NC2807855 (704)8754809 Fax 1

DUKEPOWER I

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October 4,1994 s

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.U. S. Nuclear Regulatory Commission -

Document Control Desk l

Washington, D.C. 20555 -

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Subject:

, McGuire Nuclear Station Docket Nos. 50-369 and 50-370.

t Report Pursuant to 10 CFR 50.46, Changes to or Errors in an ECCS Evaluation Model

References:

1) DPC-94-205, February 8,1994 letter from Westinghouse (J. M. Hall) to Duke Power (W. M. Sample)

2) October 18, 1993 letter from Duke Power (M. S.-Tuckman) to NRC Document Control Desk t

j 10CFR50.46(a)(3)(ii) requires reporting of changes to or _ errors in the ECCS evaluation model (EM), or in the application of the EM, which affect the LOCA peak i

clad temperature (PCT). Attached is information for small break LOCA (SBLOCA),

large break LOCA (LBLOCA) for Westinghouse OFA fuel, and LBLOCA for Mark-BW l

fuel.

Questions or problems should be directed to Kay Crane, McGuire Regulatory Compliance at (704) 875-4306.

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Very truly yours, si T. C. McMeekin, Vice President McGuire Nuclear Station i

9410140119 941004

't PDR ADOCK 05000369 P

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Document Control Desk October 4,1994 Page 2 cc:

Mr. Victor Nerses, Project Manager Office of Nuclear Reactor Regulation

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U. S. Nuclear Regulatory Commission Washington, D.C. 20555 Mr. S. D. Ebneter, Regional Administrator l

U. S. Nuclear Regulatory Commission Region II l

101 Marietta Street, NW - Suite 2900 l

Atlanta, Georgia 30323 l

Mr. George Maxwell Senior Resident Inspector McGuire Nuclear Station I

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i Attachment S11LOCA Analyses The 1985 Westinghouse ECCS EM analyses apply to all fuel types in the McGuire cores. The analyses which will be shown in the September 1,1994 McGuire FSAR include a case in which a 1264 F PCT is calculated. As shown in Reference 2,EM changes previously reponed to the NRC could result in an increase in this value by up to 137 F. Per Reference 1, them is one additional change to report, a benefit due to error corrections in the LUCIFER code. 'Ihis is a code used to generate component databases for both the large and small break LOCA analyses. The benefit is 16 F for small break analyses. Therefore, the resulting McGuire PCT is 1264 + 137 - 16 =

1385 F.

l LBLOCA Analyses for Westinghouse OFA Fuel i

The 1981 Westinghouse ECCS EM with B ASif analyses apply to the Westinghouse OFA fuelin the McGuire cores. The analyses which will be shown in the September 1,1994 McGuire FSAR include a case in which a 1945*F PCT is calculated. As shown in Table 15-28 for the previous analysis, EM changes previously reported to the NRC would result in a net decrease of 7 F. Per j

Reference 1. the reanalysis which will be included in the FS AR update eliminated tbc need to account sepamtely for a 10 F penalty which was part of these changes. The remaining changes are l

1) a 25 F benefit due to correction of the metal type (stainless steel vs. carbon steel clad with l

stainless steel) in the stnictural heat transfer model in the WREFLOOD-INTERIM computer code l

and 2) an 8 F penalty for seismically induced steam generator tube crushing occurring coincident j

with a LBLOCA. Therefore, there remain a total of-25 + 8 = -17'F of previously reponed j

changes which are relevant to the new analysis. In addition, with this reanalysis, McGuire now has sufficient PCT margin to change the method of accounting for the BASli EM potential i

nonconscivatism in assumed axial power distribution. Previously, this was accounted for by imposing a stricter surveillance requirement, a so-called L(z) penalty, on axial power distribution.

l Beginning with Cycle 10 of McGuire Unit 1, McGuire will use the same method as Catawba to account for this penalty, a 100 F PCT penalty. Finally, per Reference 1, the LUCIFER change reponed above for small break LOCA analysis results in a 6 F benefit for large break LOCA.

Therefore, the resulting McGuire LDLOCA PCT for Westinghouse OFA is 1945 -17 +100 - 6 =

2022 F.

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