W3P85-2177, Provides Results of C-E Final ECCS Reevaluation Re C-E Large Break LOCA Evaluation Model,Per 850711 Commitment.Reanalysis of Limiting Large Break LOCA Transient Results in Peak Clad Temp of 2,170 F

Provides Results of C-E Final ECCS Reevaluation Re C-E Large Break LOCA Evaluation Model,Per 850711 Commitment.Reanalysis of Limiting Large Break LOCA Transient Results in Peak Clad Temp of 2,170 F

ML20129K080
Person / Time
Site:	Waterford
Issue date:	07/19/1985
From:	Cook K LOUISIANA POWER & LIGHT CO.
To:	Knighton G Office of Nuclear Reactor Regulation
References
W3P85-2177, NUDOCS 8507230371
Download: ML20129K080 (2)

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P O W E R & L 1 G H T / N=W OA..ANS LOUSMA 70174-8000 . (504]386-9345

$1USIN SYS July 19, 1985 W3P85-2177 3-A1.01.04 A4.05 Director of Nuclear Reactor Regulation Attention: Mr. G.W. Knighton, Chief Licensing Branch No. 3 Division of Licensing U.S. Nuc1 car Regulatory Commission

SUBJECT:

Waterford SES 3 Docket No. 50-382 Combustion Engineering Large Break LOCA Evaluation Model

REFERENCE:

LP&L Letter W3P85-2501, July 11, 1985

Dear Sir:

In the referenced letter, LP&L informed the NRC of a potential nonconservatism in one element of the CE Large Break LOCA Evaluation Model. The potential non-conservatism concerned the power distribution used in the analysis. LP&L requested CE to finalize the ECCS reevaluation for Waterford 3. This letter provides the results of the reevaluation.

CE has reevaluated the large break LOCA transient using the ECCS models of the analysis of record for Waterford 3, except for the following changes in assumptions and input plant conditions:

1. The axial shape has been changed from a 1.68 top peak to a 1.52 top peak, and the radial peak has been increased to maintain the hot rod peak power at the current 13.4 LOCA KW/FT limit. CE determined that because the Waterford 3 reflood rates are generally lower than the CESSAR reflood rates the sensitivity to changes in axial power distribution is higher for Waterford 3. CE has determined that the 1.52 axial shape and associated radial peak conservatively bound the most adverse power distribution (with respect to the large break LOCA analysis) which may occur during the first cycle of Waterford 3 operation.

2. The influence of containment purge was not included. The Waterford 3 Technical Specifications, LCO 3.6.1.7, limit containment purge to not more than 90 hours0.00104 days <br />0.025 hours <br />1.488095e-4 weeks <br />3.4245e-5 months <br /> per year. The basis for climinating containment purge from the analysis was provided in the referenced letter.

3. The safety injection tank discharge line K factors were reduced from an average of 32 to 29.5. This change reficcts actual measured K factors for 0507230371 050719 2 PDR ADOCK 0D00 e

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e' Mr. G.W. Knighton W3P85-2177 Page 2 the three (3) most limiting SITS which would discharge into the RCS during this transient.

4. The initial containment temperature was raised from 80*F to 100*F. This temperature is the minimum containment temperature expected during full power operation.

The reanalysis of the limiting Large Break LOCA transient, with the changes identified above, results in a Peak Clad Temperature (PCT) of 2170*F. This PCT is below the 2200'F acceptance criteria limit for 10CFR50.46.

The results of these evaluations are submitted pursuant to the reanalysis requirement of 10CFR50, Appendix K. The analysis will be validated by LP&L and incorporated in the FSAR in accordance with 10CFR50.71(e).

Picase contact me or Robert J. Murillo if you have any questions.

Yours very truly, g6 Cat K.W. Cook Nuclear Support & Licensing Manager KWC/RJM/pc1 cc: B.W. Churchill, W.H. Stevenson, R.D. Martin, D.M. Crutchficid, J. Wilson, T.A. Flippo i

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