ANO Tripped...Lots Of Unreliablity In Their Fleet

Power Reactor	Event Number: 54091
Facility: ARKANSAS NUCLEAR Region: 4     State: AR Unit: [] [2] [] RX Type: [1] B&W-L-LP,[2] CE NRC Notified By: MICHAEL STROBEL HQ OPS Officer: DAN LIVERMORE	Notification Date: 05/26/2019 Notification Time: 09:25 [ET] Event Date: 05/26/2019 Event Time: 05:12 [CDT] Last Update Date: 05/26/2019
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): HEATHER GEPFORD (R4DO)

Unit

SCRAM Code

RX Crit

Initial PWR

Initial RX Mode

Current PWR

Current RX Mode

2

A/R

Y

100

Power Operation

0

Hot Standby

Event Text

AUTOMATIC REACTOR TRIP DUE TO A REACTOR COOLANT PUMP TRIP ON GROUND FAULT "This is a 4-hour Non-Emergency 10 CFR 50.72(b)(2)(iv)(B) notification due to a Plant Protection System (PPS) actuation. Arkansas Nuclear One, Unit 2, automatically tripped from 100 percent power at 0512 CDT. The reactor automatically tripped due to 2P-32B Reactor Coolant Pump tripping as a result of grounding. "No additional equipment issues were noted. All control rods fully inserted. Emergency Feedwater (EFW) actuated and was utilized to maintain Steam Generator (SG) levels. The EFW actuation meets the 8-hour Non-Emergency Immediate Notification Criteria of 10 CFR 50.72(b)(3)(iv)(A). No Primary safety valves lifted. Main Steam Safety Valves (MSSVs) did lift initially after the trip. "The NRC Resident Inspector has been notified. "Decay heat is being removed via the steam dump valves to the main condenser. Unit 2 is in a normal shutdown electrical lineup. Unit 1 was not affected by the transient on Unit 2. The licensee notified the State of Arkansas."