| Power Reactor | Event Number: 47479 |
| Facility: MONTICELLO Region: 3 State: MN Unit: [1] [ ] [ ] RX Type: [1] GE-3 NRC Notified By: KIRK DUEA HQ OPS Officer: HOWIE CROUCH |
Notification Date: 11/28/2011 Notification Time: 01:04 [ET] Event Date: 11/27/2011 Event Time: 16:57 [CST] Last Update Date: 11/28/2011 |
| Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(v)(D) – ACCIDENT MITIGATION |
Person (Organization): JULIO LARA (R3DO) |
| Unit | SCRAM Code | RX CRIT | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
| 1 | N | N | 0 | Startup | 0 | Startup |
Event Text
| ROD WORTH MINIMIZER CONTROL SWITCH FOUND OUT OF REQUIRED POSITION
“After transitioning to Mode 2 from Mode 4, while performing the Rod Worth Minimizer (RWM) operability test, it was discovered that the RWM control switch was in the BYPASS position. The RWM enforces predetermined control rod withdrawal and insertion sequences. Complying with these predetermined sequences ensures a Control Rod Drop Accident does not exceed analytical limits. With the control switch in the BYPASS position, the RWM was inoperable and would not have enforced the predetermined control rod withdrawal sequence. The RWM control switch was restored to the OPERATE position and the RWM was verified to be operable. “This issue is being reported under 50.72(b)(3)(v)(D) as an event or condition that at the time of discovery could have prevented the fulfillment of the safety function of the RWM, which is a system needed to mitigate the consequences of the Control Rod Drop Accident.” The licensee will be notifying the NRC Resident Inspector. |
The Monticello Nuclear Generating Plant is a nuclear power plant located in Monticello, Minnesota, along the Mississippi River. The site, which began operating in 1971, has a single nuclear reactor(boiling water reactor) of the General Electric BWR-3 design generating 613 megawatts, but studies are ongoing to uprate it to 700 MWe.
Currently the plant is both owned and operated by Xcel Energy
Source: NRC Event Notifications
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