United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for April 27, 2006

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Part 21 2006-0007 - Interim Report from Areva NP on "Control Rod Performance During LOCA"

Licensee/Facility:


AREVA
Lynchburg, Virginia
Dockets:

License No:
Notification:

MR Number: H-2006-0009
Date: 04/13/2006


Source Document: Letter

Reviewer: Mark King

Discussion:

Areva NP, Inc. notified the NRC on April 13, 2006 of an Interim Report of an Evaluation of a Deviation Pursuant to 10 CFR 21.21 (a)(2) titled: "Control Rod Performance During LOCA." The issue is related to the possibility that the control rods could melt during a loss of coolant accident (LOCA), potentially impacting the analyses performed to demonstrate compliance with the criteria in 10 CFR 50.46.

This issue was identified as a result of a question from First Energy for which loss of coolant accident (LOCA) analyses for the Davis-Besse plant had recently been performed to support use of a new fuel design. The question was whether the control rod temperature analysis, which was described in the Updated Safety Analysis Report (USAR), had been re-evaluated. Investigation revealed that the control rod heatup analyses had not been updated.

Analyses demonstrating compliance with the 10 CFR 50.46 criteria, to specifically demonstrate that those plants with full-length silver-indium-cadmium (AIC) control rods will not exceed temperatures at which they could affect local core cooling, long term core cooling, or coolable geometry criteria needs to be completed to conclude that this issue is not a Part 21 defect and that all plants continue to meet the safety criteria. Those Areva customers affected by this current control rod heatup issue have been provided information to support operability evaluations. Preliminary analysis, evaluations and engineering judgement provide sufficient evidence to support the conclusion that the control rods will continue to satisfy their safety function during a postulated LOCA with higher control rod temperatures. This conclusion is valid for both large and small break LOCAs. It is expected that the final evaluation will conclude that this issue is not a Part 21 defect. The evaluation is expected to be completed by Areva on or before January 15, 2007.

Areva NP supplies fuel to Babcock and Wilcox (B&W), Westinghouse (W) and Combustion Engineering (CE) designed pressurized water reactors (PWRs). Areva informed the NRC that the following customers have been notified and they will receive a copy of the Interim Report No. 06-001, "Control Rod Performance During LOCA": Exelon, Dominion, TVA, Progress Energy, Nuclear Management Co., Duke Power, Florida Power and Light, FirstEnergy, Entergy, and Omaha Public Power District.

The Areva Interim Report 06-001 is also available in NRC ADAMS under ML061070297.

Accession Numbers:

Accession No Accession Date
ML061070297 04/13/2006

Contacts:

Name Office Abbrev Phone No E-Mail
KING, MARK S NRR (301) 415-1150 MSK1@nrc.gov
TABATABAI, OMID NRR (301) 415-6616 OTY@nrc.gov
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