Event Notification Report for April 24, 2015
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/23/2015 - 04/24/2015
EVENT NUMBERS
51013
Power Reactor
Event Number: 51013
Facility: PRAIRIE ISLAND
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: NATHAN BIBUS
HQ OPS Officer: DONALD NORWOOD
Region: 3 State: MN
Unit: [1] [] []
RX Type: [1] W-2-LP,[2] W-2-LP
NRC Notified By: NATHAN BIBUS
HQ OPS Officer: DONALD NORWOOD
Notification Date: 04/25/2015
Notification Time: 04:10 [ET]
Event Date: 04/24/2015
Event Time: 21:25 [CDT]
Last Update Date: 04/25/2015
Notification Time: 04:10 [ET]
Event Date: 04/24/2015
Event Time: 21:25 [CDT]
Last Update Date: 04/25/2015
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
10 CFR Section:
50.72(b)(3)(xiii) - LOSS COMM/ASMT/RESPONSE
Person (Organization):
NICK VALOS (R3DO)
NICK VALOS (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
LOSS OF EMERGENCY ASSESSMENT CAPABILITY DUE TO OUT-OF-SERVICE RADIATION MONITORS
"At 2125 on 4/24/15, 1R-2, Containment Vessel Area Radiation Detector failed. Previously, 1R-7, Incore Seal Table Area Radiation Detector, had failed on 4/20/15. The compensatory measure for 1R-2 out-of-service is to verify 1R-7 operating properly and the compensatory measure for 1R-7 out-of-service is to verify 1R-2 operating properly. With both monitors out-of-service and Unit 1 operating in Mode 5, no compensatory measure is available that will allow timely classification of two Emergency Action Levels (EALs) - Notification of Unusual Event (NUE) classification (RU2.2) and Alert classification (RA3.2). This results in a Loss of Emergency Assessment Capability while 1R-2 and 1R-7 are concurrently out-of-service. This is a reportable condition per 10 CFR 50.72(b)(3)(xiii).
"Monitoring of radiological conditions in Unit 1 Containment showed no indication of RCS leakage or elevated radiation levels prior to the failure of 1R-2. Unit 1 Containment also remains monitored by 1R-48, Containment Hi Range Area Radiation Detector A and 1R-49, Containment Hi Range Area Radiation Detector B, which currently indicate normal radiation levels. Unit 1 Shield Building Stack is also monitored by 1R-50, Shield Building High Range Vent Gas Radiation Detector, which also currently indicates normal radiation levels. Additionally, a temporary portable radiation monitor has been placed near the location of 1R-2 and is being continuously monitored.
"The plant remains in a safe condition and there was no effect to the health and safety of the public.
"The licensee has notified the NRC Resident Inspector."
"At 2125 on 4/24/15, 1R-2, Containment Vessel Area Radiation Detector failed. Previously, 1R-7, Incore Seal Table Area Radiation Detector, had failed on 4/20/15. The compensatory measure for 1R-2 out-of-service is to verify 1R-7 operating properly and the compensatory measure for 1R-7 out-of-service is to verify 1R-2 operating properly. With both monitors out-of-service and Unit 1 operating in Mode 5, no compensatory measure is available that will allow timely classification of two Emergency Action Levels (EALs) - Notification of Unusual Event (NUE) classification (RU2.2) and Alert classification (RA3.2). This results in a Loss of Emergency Assessment Capability while 1R-2 and 1R-7 are concurrently out-of-service. This is a reportable condition per 10 CFR 50.72(b)(3)(xiii).
"Monitoring of radiological conditions in Unit 1 Containment showed no indication of RCS leakage or elevated radiation levels prior to the failure of 1R-2. Unit 1 Containment also remains monitored by 1R-48, Containment Hi Range Area Radiation Detector A and 1R-49, Containment Hi Range Area Radiation Detector B, which currently indicate normal radiation levels. Unit 1 Shield Building Stack is also monitored by 1R-50, Shield Building High Range Vent Gas Radiation Detector, which also currently indicates normal radiation levels. Additionally, a temporary portable radiation monitor has been placed near the location of 1R-2 and is being continuously monitored.
"The plant remains in a safe condition and there was no effect to the health and safety of the public.
"The licensee has notified the NRC Resident Inspector."