Peach Bottom - AUTOMATIC SCRAM DUE TO ELECTRICAL TRANSIENTS

U.S. Nuclear Regulatory Commission
Operations Center
 
EVENT REPORTS FOR
05/17/2022 - 05/18/2022
 
55899
Power Reactor
Event Number: 55899
Facility: Peach Bottom
Region: 1     State: PA
Unit: [2] [] []
RX Type: [2] GE-4,[3] GE-4
NRC Notified By: Linell, Bill
HQ OPS Officer: Brian P. Smith Notification Date: 05/16/2022
Notification Time: 19:51 [ET]
Event Date: 05/16/2022
Event Time: 15:52 [EDT]
Last Update Date: 05/16/2022 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):
Lilliendahl, Jon (R1DO)
Power Reactor Unit Info
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 SCRAM DUE TO ELECTRICAL TRANSIENTS
 
The following information was provided by the licensee via fax:
 
"Unit 2 experienced multiple electrical transients resulting in a Group I Primary Containment Isolation Signal (PCIS) isolation and subsequent unit reactor scram. Low reactor water level during the automatic scram caused PCIS Group II and III isolation signals. Following the PCIS Group I isolation, all main steam lines isolated. All control rods inserted and all systems operated as designed."
 
The following additional information was obtained from the licensee via phone in accordance with Headquarters Operations Officers Report Guidance:
 
Peach Bottom Unit 2 automatically scrammed from 100 percent power due to an electrical transient and subsequent PCIS Group I isolation (Main Steam Isolation Valve closure). Unit 2 lost main feedwater due to the PCIS Group I isolation, however, all other systems responded as expected following the scram. High Pressure Coolant Injection is maintaining pressure control while Condensate Pumps are maintaining inventory. The unit is currently stable and in Mode 3. Peach Bottom Unit 3's Adjustable Speed Drives were impacted by the electrical transients and the unit reduced power to 98 percent power.
 
The NRC Resident Inspector was notified.