ECCS Computer Codes wrong for Davis Besse and TMI and Oconee and ANO

Part 21	Event Number: 50636
Rep Org: AREVA, INC. Licensee: AREVA, INC. Region: 1 City: LYNCHBURG State: VA County:  License #:  Agreement: Y Docket:  NRC Notified By: GAYLE ELLIOTT HQ OPS Officer: JOHN SHOEMAKER	Notification Date: 11/25/2014 Notification Time: 10:10 [ET] Event Date: 10/19/2014 Event Time: [EST] Last Update Date: 11/25/2014
Emergency Class: NON EMERGENCY 10 CFR Section:  21.21(d)(3)(i) - DEFECTS AND NONCOMPLIANCE	Person (Organization):  JAMES NOGGLE (R1DO) FRANK EHRHARDT (R2DO) ERIC DUNCAN (R3DO) VIVIAN CAMPBELL (R4DO) PART 21 GROUP (EMAI) HAROLD CHERNOFF (EMAI)

Event Text

PART 21 - DEFECT IN LOCA ANALYSIS FOR B&W PLANTS  The following information was summarized from the report obtained from the vendor via facsimile:  "The defect is related to the thermal conductivity model in the codes TACO3 and GDTACO which are used in the AREVA LOCA model for B&W plants. The thermal conductivity model does not adequately represent the change in conductivity with burnup for the fuel. The correction of the thermal conductivity model results in the peak cladding temperature limit in 10 CFR 50.46 (2200 degrees F) being exceeded.  "The defect exists for the following plants: Oconee Nuclear Station Unit 1, Oconee Nuclear Station Unit 2, Oconee Nuclear Station Unit 3, Arkansas Nuclear One Unit 1, Three Mile Island Unit 1, and Davis-Besse Unit 1"  If there are any technical questions or concerns, please contact:  Gayle Elliott  AREVA, lnc., 3315 Old Forest Road  Lynchburg, VA 24501  Ph. # 434-841-0306.