Junk Plant ANO Unit 1 Trips Too

See! How overloaded is Entergy with both plants tripped?

Power Reactor	Event Number: 53793
Facility: ARKANSAS NUCLEAR Region: 4     State: AR Unit: [1] [] [] RX Type: [1] B&W-L-LP,[2] CE NRC Notified By: SEAN DAVIS HQ OPS Officer: DONG HWA PARK	Notification Date: 12/18/2018 Notification Time: 15:40 [ET] Event Date: 12/18/2018 Event Time: 00:00 [CST] Last Update Date: 12/18/2018
Emergency Class: NON EMERGENCY 10 CFR Section: 50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION	Person (Organization): RYAN ALEXANDER (R4DO)

Unit

SCRAM Code

RX Crit

Initial PWR

Initial RX Mode

Current PWR

Current RX Mode

1

A/R

Y

100

Power Operation

0

Hot Standby

Event Text

AUTOMATIC REACTOR TRIP - LOSS OF NON-VITAL BUS "On December 18, 2018 at 1126 CST, Arkansas Nuclear One, Unit 1 (ANO-1) reactor automatically tripped due to a loss of the A-1, non-vital 4160V bus. All control rods fully inserted. Loss of the A-1 bus resulted in de-energizing A-3 vital 4160V bus. Emergency Diesel Generator #1, K-4A, started automatically and is currently powering A-3 vital bus. Non-vital buses A-2, H-1, and H-2 and vital bus A-4 transferred power automatically to the Startup Transformer #1. Off-site power remains energized and available for ANO-1. The reason for loss of A-1 bus is unknown at this time. Currently, ANO-1 has stabilized in Mode 3, Hot Standby." Decay heat is being removed by the main condenser using the turbine bypass valves. The loss of the A-1, non-vital bus, is under investigation. The licensee has notified the NRC Resident Inspector and the state.