Event Notification Report for August 22, 2015
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
08/21/2015 - 08/22/2015
EVENT NUMBERS
51338
51338
Power Reactor
Event Number: 51338
Facility: PILGRIM
Region: 1 State: MA
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: KEN GRACIA
HQ OPS Officer: JOHN SHOEMAKER
Region: 1 State: MA
Unit: [1] [] []
RX Type: [1] GE-3
NRC Notified By: KEN GRACIA
HQ OPS Officer: JOHN SHOEMAKER
Notification Date: 08/22/2015
Notification Time: 20:14 [ET]
Event Date: 08/22/2015
Event Time: 16:28 [EDT]
Last Update Date: 08/22/2015
Notification Time: 20:14 [ET]
Event Date: 08/22/2015
Event Time: 16:28 [EDT]
Last Update Date: 08/22/2015
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
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS ACTUATION - CRITICAL 50.72(b)(3)(iv)(A) - VALID SPECIF SYS ACTUATION
Person (Organization):
ANNE DeFRANCISCO (R1DO)
ANNE DeFRANCISCO (R1DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 100 | Power Operation | 0 | Hot Shutdown |
REACTOR SCRAM DUE TO A SINGLE MSIV CLOSURE
"On Saturday, August 22, 2015, at 1628 [EDT], with the reactor at 100% core thermal power (CTP) the Pilgrim Nuclear Power Station (PNPS) experienced an automatic reactor scram signal due to the rapid closure of one main steam isolation valve (MSIV). Other than the MSIV all other plant systems responded as designed. Plant cooldown is in progress using steam bypass to the main condenser.
"The plant is in hot shutdown. The cause of the MSIV closure is still under investigation. This event has no impact on the health and safety of the public. The licensee has notified the NRC Senior Resident Inspector.
"This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), 'Any event that results in actuation of the reactor protection system (RPS) when the reactor is critical'.
"Subsequent to the reactor scram the plant experienced the following isolation signals:
- Group 2 Isolation: Miscellaneous containment isolation valves
- Group 6 Isolation: Reactor Water Clean-up
- Reactor Building Isolation Actuation
"This notification is also being made in accordance with 10 CFR 50.72(b)(3)(iv)(A), 'Any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section' (B)(2) 'General containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs).'"
Plant response was considered normal and the plant is in a stable shutdown / cooldown condition. The license will be notifying the Commonwealth of Massachusetts.
"On Saturday, August 22, 2015, at 1628 [EDT], with the reactor at 100% core thermal power (CTP) the Pilgrim Nuclear Power Station (PNPS) experienced an automatic reactor scram signal due to the rapid closure of one main steam isolation valve (MSIV). Other than the MSIV all other plant systems responded as designed. Plant cooldown is in progress using steam bypass to the main condenser.
"The plant is in hot shutdown. The cause of the MSIV closure is still under investigation. This event has no impact on the health and safety of the public. The licensee has notified the NRC Senior Resident Inspector.
"This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), 'Any event that results in actuation of the reactor protection system (RPS) when the reactor is critical'.
"Subsequent to the reactor scram the plant experienced the following isolation signals:
- Group 2 Isolation: Miscellaneous containment isolation valves
- Group 6 Isolation: Reactor Water Clean-up
- Reactor Building Isolation Actuation
"This notification is also being made in accordance with 10 CFR 50.72(b)(3)(iv)(A), 'Any event or condition that results in valid actuation of any of the systems listed in paragraph (b)(3)(iv)(B) of this section' (B)(2) 'General containment isolation signals affecting containment isolation valves in more than one system or multiple main steam isolation valves (MSIVs).'"
Plant response was considered normal and the plant is in a stable shutdown / cooldown condition. The license will be notifying the Commonwealth of Massachusetts.