United States Nuclear Regulatory Commission - Protecting People and the Environment

Morning Report for March 3, 2005

Headquarters Daily Report

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REGION II

Part 21 2005-0011: Minimum Critical Power Ration (MCPR) Operating and Monitoring Limits

Licensee/Facility:

FRAMATOME ANP RICHLAND, INC.
FRAMATOME ANP RICHLAND
RICHLAND, Washington
Dockets: 07001257

License No: SNM-1227
Notification:

MR Number: H-2005-0008
Date: 03/02/2005


Source Document: Fax

Reviewer: TABATABAI, OMID

Discussion:

Part 21 2005-0011: Minimum Critical Power Ration (MCPR) Operating and Monitoring Limits

The following information was provided by Framatome ANP. (See EN 41455)

The defect involves the Minimum Critical Power Ratio (MCPR) operating limit and the monitoring of that limit. On 01/27/05, Framatome ANP determined that a deviation exists in the interpolation scheme for MCPR within a range of fuel bundle flows, between 0.37 and 0.48 Mlb/hr/ft2, for several operating plants. The condition could be experienced during startup, shutdown, or for other generally very infrequent reasons with core flows in the 30-45% range. The error has no impact on reactor operation above 45% flow.

Affected Plants

The plants where the MCPR operating limit was affected are Browns Ferry Unit 3 and Grand Gulf. The plants where the steady state MCPR predicted by the monitoring system was affected are Browns Ferry Unit 3, Columbia Generating Station, Grand Gulf, LaSalle Unit 2, and River Bend.

Vendor Corrective Actions

The vendor has corrected the coding errors in the affected codes at Framatome ANP. Vendor has also notified all affected plants and had provided recommendations for compensatory actions to those plants (Grand Gulf and River Bend) where the impact of the error is evident for current and future cycle exposures. Compensatory measures have been provided to the affected plants for use until the incore monitoring code can be updated at each plant.

Contacts:

Name Office Abbrev Phone No E-Mail
TABATABAI, OMID NRR (301) 415-6616 OTY@nrc.gov
Page Last Reviewed/Updated Thursday, March 29, 2012