LIC-96-0034, Submits Annual 10CFR50.46 Summary Rept for 1995.Summary Rept Updates Identified Changes/Error in Loca/Eccs Codes & Methods Used by Westinghouse to Model Unit 1

Submits Annual 10CFR50.46 Summary Rept for 1995.Summary Rept Updates Identified Changes/Error in Loca/Eccs Codes & Methods Used by Westinghouse to Model Unit 1

ML20101E231
Person / Time
Site:	Fort Calhoun
Issue date:	03/15/1996
From:	Tira Patterson OMAHA PUBLIC POWER DISTRICT
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LIC-96-0034, LIC-96-34, NUDOCS 9603220209
Download: ML20101E231 (6)

Text

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$998 Omaha Public PowerDistrict 444 South 16th Street Mall Omaha NE68102-2247 March 15, 1996 LIC-96-0034 1

U.S. Nuclear Regulatory Commission Attn: Document Control Desk j Mail Station P1-137  :

Washington, D.C. 20555 l

References:

1. Docket No. 50-285

2. WCAP-13027-P, " Westinghouse ECCS Evaluation Model for Analysis  ;

of CE-NSSS," dated July 1991

3. WCAP-13451, " Westinghouse Methodology for Implementation of 10 CFR 50.46 Reporting," dated October 1992

4. WCAP-10054-P, Addendum 2, " Addendum to the Westinghouse Small Break ECCS Evaluation Model Using the NOTRUMP Code: Safety Injection into the Broken Loop and COSI Condensation Model,"

dated August, 1994

SUBJECT:

Annual Report for 1995 Loss of Coolant Accident (LOCA)/ Emergency i Core Cooling System (ECCS) Models In accordance with 10 CFR 50.46(a)(3)(ii), the Omaha Public Power District (0 PPD) is submitting the annual 10 CFR 50.46 summary report for 1995. This summary report updates all identified changes or errors in the LOCA/ECCS codes and methods used by Westinghouse Electric Corporation (W) to model Fort Calhoun Station (FCS) Unit No. 1. Reference 2 describes the methodology utilized by W to model Combustion Engineering plants, such as FCS.

Attachment I contains the one error and change identified using the NOTRUMP code for the small break LOCA (SBLOCA) analysis.

Attachment 2 summarizes the small break LOCA/ECCS peak clad temperature (PCT)

. margin utilization and the large break LOCA/ECCS PCT margin utilization.

9603220209 960315 PDR ADOCK 05000285 R PDR l l i 45.5134 Employment with Equal OpportunPy f

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U. S. Nuclear Regulatory Commission l LIC-96-0034 l Page Two )

l In conclusion, the cumulative errors / changes identified or implemented through 1995 result in a net increase of 20'F PCT for the SBLOCA analysis and no change in PCT for the large break LOCA (LBLOCA) analysis. The resultant SBLOCA PCT )

still remains less than the 10 CFR 50.46(b)(1) acceptance criteria of 2200*F.

If you should have any questions, please contact me.

]

Sincerely, T. L. Patterson k  :

Division Manager Nuclear Operations TLP/dll Attachments c: Winston & Strawn L. J. Callan, NRC Regional Administrator, Region IV L. R. Wharton, NRC Project Manager i W. C. Walker, NRC Senior Resident Inspector I n_

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LIC-96-0034 Attachment 1 I

I FORT CALHOUN STATION l SMALL BREAK LOCA ANALYSIS NOTRUMP SPECIFIC ENTHALPY ERROR l

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LIC-96-0034 Attachment 1 l

NOTRUMP Specific Enthalpy Error Affected Evaluation Model 1985 Westinghouse Small Break Loss-of-Coolant-Accident (LOCA) Evaluation Model Using NOTRUMP l

Backaround A typogrrphical error was found in a line of coding in the NOTRUMP code. This line of coding was intended to model the calculation found in Equation L-127 of WCAP-0079-P-A. Although the equation in the topical report is correct, the  !

coding represented the last term as a partial derivative with respect to the l fluid node mixture region total energy instead of the mixture region total mass, i This correction is a Non-Discretionary Change in accordance with Section 4.1.2 1 of WCAP-13451. l Estimated Effect Representative plant calculations have led to an estimated effect of +20*F for this error correction.

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! LIC-96-0034 Attachment 2 i

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! FORT CALHOUN STATION LOCA PEAK CLAD TEMPERATURE (PCT)

NARGIN UTILIZATION SHEETS i

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, LIC-96-0034 Attachment 2 1

1995 SMALL BREAK PEAK CLAD TEMPERATURE MARGIN UTILIZATION FORT CALHOUN STATION UNIT NO. 1 CLAD TEMPERATURE A. Analysis of Record (8/91) PCT = 1444 F B. Prior Permanent ECCS Model Assessments APCT = -34 F ,

C. 10 CFR 50.59 Safety Evaluations APCT = 0*F D. 10 CFR 50.46 Model Assessments this Update 1 (Permanent Assessment of PCT Margin) NOTRUMP Specific APCT = 20*F E. Enthalpy Error Temporary ECCS Model Issues - None APCT = 0*F F. Other Margin Allocations - None APCT = 0*F )

LICENSING BASIS PCT + MARGIN ALLOLATIONS PCT = 1430 F l

1995 LARGE BREAK PEAK CLAD TEMPERATURE MARGIN UTILIZATION FORT CALHOUN STATION UNIT NO. 1 CLAD TEMPERATURE A. Analysis of Record (8/91) PCT = 2066 F B. Prior Permanent ECCS Model Assessments APCT = -25 F l C. 10 CFR 50.59 Safety Evaluations APCT = 0*F i D. 199510 CFR 50.46 Model Assessments APCT = 0F (Permanent Assessment of PCT Margin) - None E. Temporary ECCS Model Issues - None APCT = 0*F F. Other Margin Allocations - None APCT = 0F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 2041*F

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