US Nuclear Plants Woefully Unprepared for Polar Vortex

They should have started up the DGs once they entered Tech Spec in order to assure operability?

Power Reactor	Event Number: 53853
Facility: PRAIRIE ISLAND Region: 3     State: MN Unit: [] [2] [] RX Type: [1] W-2-LP,[2] W-2-LP NRC Notified By: DOUG LARSON HQ OPS Officer: MARK ABRAMOVITZ	Notification Date: 01/31/2019 Notification Time: 10:48 [ET] Event Date: 01/31/2019 Event Time: 07:43 [CST] Last Update Date: 01/31/2019
Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(3)(v)(D) - ACCIDENT MITIGATION	Person (Organization): JAMNES CAMERON (R3DO)

Unit

SCRAM Code

RX Crit

Initial PWR

Initial RX Mode

Current PWR

Current RX Mode

2

N

Y

100

Power Operation

100

Power Operation

Event Text

BOTH EMERGENCY DIESEL GENERATORS INOPERABLE DUE TO LOW AIR TEMPERATURE "At 0743 [CST] on 1/31/2019, both trains of Unit 2 Diesel Generators were declared INOPERABLE due to outside air temperature exceeding the low temperature design limit for the diesel engines; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v) for an event or condition that could have prevented the fulfillment of a safety function. The Unit 2 Diesel Generators are still able to start if necessary to provide power. Additionally, multiple layers of defense in depth measures are in place to ensure safety. Prairie Island has five sources of offsite power; all of which are currently available. The Unit 1 Diesel Generators are OPERABLE and capable of being cross-connected to Unit 2. Additional equipment capable of responding to beyond design basis events is available on site providing another layer of defense in depth. "Both Unit 2 Diesel Generators were returned to an OPERABLE status at 0810 on 1/31/2019 based on outside air temperature rising above the low temperature design limit with forecasted temperatures to remain above the low temperature design limit. "There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified." The air temperature limit was -30 degrees Fahrenheit. Unit 1 was not affected. The EDGs were supplied by a different manufacturer with different air temperature limits.