United States Nuclear Regulatory Commission - Protecting People and the Environment

Power Reactor Event Number: 37874
FACILITY: FRAMATOME ANP RICHLAND INC REGION: 4 NOTIFICATION DATE: 03/29/2001
UNIT: STATE: WA NOTIFICATION TIME: 17:58[EST]
RXTYPE: EVENT DATE: 03/29/2001
EVENT TIME: 14:00[EST]
NRC NOTIFIED BY: MALLAY LAST UPDATE DATE: 03/28/2001
HQ OPS OFFICER: CHAUNCEY GOULD
PERSON ORGANIZATION
EMERGENCY CLASS: N/A EDWARD MCALPINE R4
10 CFR SECTION: BRUCE BURGESS R3
CCCC 21.21 UNSPECIFIED PARAGRAPH MICHELE EVANS R1
VERN HODGE NRR

EVENT TEXT

PART 21 - AN INCORRECT COMPUTER CODE WAS SUPPLIED BY FRAMATOME TO FOUR LICENSEES FOR CALCULATION OF THE MINIMUM CRITICAL POWER RATIO (MCPR)

In the performance of the analysis used to establish the MCPR operating limits, the use of an inappropriate reference temperature resulted in an overprediction of the thermal conductivity of the fuel. This overprediction produced MCPR operating limits that were lower than they should have been. Therefore, the MCPR limits must be raised by up to 0.01 or 0.02, depending on the affected power plants.

The MCPR must be raised by up to 0.01 from the limits previously provided for Dresden Units 2 and 3, and for Quad Cities Units 1 and 2. The MCPR limits for LaSalle Units 1 and 2 must be revised by up to 0.01 for power levels of 60 percent and above and by up to 002 below 60 percent. Calculations for Susquehanna Units 1 and 2 were affected but the MCPR limits were unchanged. Continued compliance with the over-pressurization criteria specified by the ASME code has been demonstrated.

All units, including Susquehanna, have been notified. Compensatory measures have been provided to the affected plants until confirmatory analyses have been completed. The appropriate reference temperature has been installed in the computer code used for the MCPR analysis.

Page Last Reviewed/Updated Thursday, March 29, 2012