United States Nuclear Regulatory Commission - Protecting People and the Environment

Power Reactor Event Number: 38119
FACILITY: FERMI REGION: 3 NOTIFICATION DATE: 07/05/2001
UNIT: [ 2 ] [ ] [ ] STATE: MI NOTIFICATION TIME: 16:03[EDT]
RXTYPE: [2] GE-4    EVENT DATE: 07/05/2001
      EVENT TIME: 10:00[EDT]
NRC NOTIFIED BY: COSEI LAST UPDATE DATE: 07/05/2001
HQ OPS OFFICER: CHAUNCEY GOULD      
      PERSON ORGANIZATION
EMERGENCY CLASS: NON EMERGENCY ROGER LANKSBURY R3
10 CFR SECTION:   
|AINA 50.72(b)(3)(v)(A) POT UNABLE TO SAFE SD      
                    
UNIT SCRAM CODE RX CRIT INIT PWR INIT RX MODE CURR PWR CURR RX MODE
2 N Y 100 Power Operation 100 Power Operation

EVENT TEXT

NON-CONSERVATIVE ANALYSIS FOR OPRM SCRAM SETPOINTS

On July 5, 2001, Detroit Edison received confirmation from General Electric of a non-conservative analysis that supports Operation Power Range Monitor (OPRM) scram setpoints. The non-conservative analysis is generic and been determined to affect Fermi 2. The OPRM had been conservatively declared inoperable on June 27, 2001, at 1333 hours as a result of preliminary notification by General Electric.

The consequences of the non-conservative analysis are that the associated OPRM Reactor Protective System (RPS) scram setpoints are non-conservative. The non-conservative RPS setpoints may result in violating the Minimum Critical Power Ratio (MCPR) safety limit during a thermal-hydraulic instability.

All OPRM channels have been declared inoperable. Technical Specification 3.3.1.1 Action J requires an alternate method of detecting and suppressing thermal-hydraulic instabilities to be implemented within 12 hours. Alternate methods have been established, thus, the Technical Specification required action is satisfied. Fermi 2 has 120 days to restore the OPRMs to an operable condition.

This initial report is being made in accordance with 10CFR50.72 (B)(3)(V)(A) as a condition that could have prevented the fulfillment of the safety function of a system needed to shutdown the reactor.

See EN #38104, GE Nuclear Energy 10CFR21 report.

The NRC Resident Inspector will be notified.

Page Last Reviewed/Updated Thursday, March 29, 2012