NRC 2003-0036, ECCS Evaluation Model Changes, 10 CFR 50.46

ECCS Evaluation Model Changes, 10 CFR 50.46

ML031130433
Person / Time
Site:	Point Beach
Issue date:	04/11/2003
From:	Cayia A Nuclear Management Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC 2003-0036
Download: ML031130433 (3)

Text

Committed to NucleaExcene Point Beach Nuclear Plant Operated by Nuclear Management Company, LLC NRC 2003-0036 10 CFR 50.46 April 11, 2003 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 DOCKETS 50-266 AND 50-301 ECCS EVALUATION MODEL CHANGES, 10 CFR 50.46 As required by 10 CFR 50.46(a)(3)(ii), Nuclear Management Corporation, LLC (Licensee) is submitting this annual report of changes to, and errors discovered in, emergency core cooling system (ECCS) evaluation models for Point Beach Nuclear Plant (PBNP) Units 1 and 2. This letter is intended to provide a summary of ECCS evaluation model changes and errors identified since our previous annual report dated May 10, 2002. Model changes include changes to the large break loss of coolant accident (LOCA) model and the small break LOCA model. Any changes are summarized below with additional details and a summary sheet of peak cladding temperature (PCT) margin provided in the attachment.

For PBNP Units 1 and 2, there were no changes or errors to the Best Estimate LOCA methodology since the last reporting period that resulted in a change to the PCT. In addition, there were no changes or errors in the small break LOCA evaluation model that resulted in a change to the PCT.

Current PCT rack-up sheets are provided in the attachment to this letter.

This letter contains no new commitments.

A..Cia Sit ice Pre dent JRO/ d Attachment cc: NRC Regional Administrator NRR Project Manager NRC Resident Inspector PSCW 6590 Nuclear Road

• Two Rivers, Wisconsin 54241 Telephone 920.755 2321

NRC 2003-0036 Page 1 of 2 ECCS EVALUATION MODEL CHANGES AND ERRORS Large Break LOCA Evaluation Model There were no changes or errors during this reporting period that resulted in a change to the calculated PCT for Point Beach Nuclear Plant.

Small Break LOCA Evaluation Model There were no changes or errors during this reporting period that resulted in a change to the calculated PCT for Point Beach Nuclear Plant.

NRC 2003-0036 Page 2 of 2 LARGE BREAK PEAK CLADDING TEMPERATURE MARGIN UTILIZATION FOR BELOCA PBNP Units 1 & 2:

A. Analysis of Record (11/2000) PCT = 21280 F B. Prior Permanent ECCS Model Assessments

1. MONTECF Decay Heat Uncertainty Factor APCT = 40F C. 10 CFR 50.59 Safety Evaluations (none) APCT = 0F D. 2002 10 CFR 50.46 Model Assessments (none) APCT = 0F E. Temporary ECCS Model Issues (none) APCT = 00F F. Other Margin Allocations (none) APCT = 0F Licensing Basis PCT + Margin Allocations PCT = 21320 F SMALL BREAK PEAK CLADDING TEMPERATURE MARGIN UTILIZATION (Three Inch Cold Leg)

PBNP Units 1 / 2:

A. Analysis of Record (11/2000) PCT= 1157 0F/10460 F B. Prior Permanent ECCS Model Assessments

1. NOTRUMP Mixture Level Tracking/Region Depletion APCT = 130F C. 10 CFR 50.59 Safety Evaluations (none) APCT = 0F D. 2002 10 CFR 50.46 Model Assessments (none) APCT = 0F E. Temporary ECCS Model Issues (none) APCT = 0F F. Other Margin Allocations (none) APCT = 0F Licensing Basis PCT + Margin Allocations PCT= 1170 0 F/10590 F

• • Unit 1/Unit 2