United States Nuclear Regulatory Commission - Protecting People and the Environment

Power Reactor Event Number: 38106
FACILITY: NINE MILE POINT REGION: 1 NOTIFICATION DATE: 06/29/2001
UNIT: [ ] [ 2 ] [ ] STATE: NY NOTIFICATION TIME: 19:19[EDT]
RXTYPE: [1] GE-2,[2] GE-5    EVENT DATE: 06/29/2001
      EVENT TIME: 17:15[EDT]
NRC NOTIFIED BY: ANTHONY PETRELLI LAST UPDATE DATE: 06/29/2001
HQ OPS OFFICER: FANGIE JONES      
      PERSON ORGANIZATION
EMERGENCY CLASS: NON EMERGENCY RICHARD BARKLEY R1
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 June 29, 2001, General Electric informed Niagara Mohawk Power Corporation of a non-conservative analysis that supports Operation Power Range Monitor (OPRM) scram setpoints. The non-conservative analysis is generic and has the potential to affect all stability option III and I-D plants.

"The consequences of the non-conservative analysis are that the associated OPRM Reactor Protection System (RPS) scram setpoints are also 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 F requires an alternate method of detecting and suppressing thermal-hydraulic instabilities to be implemented within 12 hours. Alternate methods are already established in procedures N2-SOP-29 and N2-RESP-12. Therefore, the Technical Specification required action is satisfied. These alternate methods are the same methods used prior to implementation of the OPRM scram function.

"Nine Mile Point Unit 2 has 120 days to restore the OPRMs to an operable condition. If the 120 day allowed outage time is exceeded, the Unit must be in at least STARTUP within the following six hours.

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

The licensee notified the NRC Resident Inspector.

See EN #38104, GE Nuclear Energy 10 CFR 21 report.

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