Event Notification Report for September 10, 2000
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
09/09/2000 - 09/10/2000
Power Reactor
Event Number: 37302
Facility: WATTS BAR
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BENJAMIN HUNT
HQ OPS Officer: BOB STRANSKY
Region: 2 State: TN
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: BENJAMIN HUNT
HQ OPS Officer: BOB STRANSKY
Notification Date: 09/10/2000
Notification Time: 19:55 [ET]
Event Date: 09/10/2000
Event Time: 16:28 [EDT]
Last Update Date: 09/10/2000
Notification Time: 19:55 [ET]
Event Date: 09/10/2000
Event Time: 16:28 [EDT]
Last Update Date: 09/10/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - ESF ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - ESF ACTUATION
Person (Organization):
MARK LESSER (R2)
MARK LESSER (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
AUTOMATIC START OF TURBINE DRIVEN AUXILIARY FEEDWATER PUMP
"At 1628 hours on 9/10/2000, with the reactor in Mode 5 for a refueling outage; Watts Bar engineering reported preliminary results of an investigation into the inadvertent start of the turbine driven auxiliary feedwater pump. At approximately 0200 hours on 9/10/2000, operators found the auxiliary feedwater pump operating without the presence of start signal. Steam generator level was being provided by previously started motor driven AFW pumps and operations secured the turbine driven pump. There was no impact from the event on plant refueling preparations and no safety consequence.
"There was no valid AFW start signal in place at the time and plant conditions were not such that a signal was required. Engineering was requested to investigate the event and identified that at about the time of the pump start, maintenance technicians were working in an adjacent part of this rack where the relay believed to have been involved in the actuation is located. A review of the circuit determined that an inadvertent bump of the relay could result in the start of the pump and the independent actuation of turbine driven AFW steam generator level control valves. Based on this information, Operations concluded that based on the preliminary engineering information an invalid start of an ESF train had occurred and declared the event reportable under 10 CFR 50.72(b)(2)(ii) and 50.73(a)(2)(iv).
"At the time the pump was found in operation it was known that there was no valid start signal, but it was thought that the issue involved only a single component. Because other S/G level maneuvers were in process independent of the AFW start, it was not recognized at the time that the level control valves were involved in the event. After the preliminary engineering review, it was concluded that although it was an invalid actuation, the event involved a train level actuation and was, therefore, reportable."
The NRC resident inspector has been informed of this event by the licensee.
"At 1628 hours on 9/10/2000, with the reactor in Mode 5 for a refueling outage; Watts Bar engineering reported preliminary results of an investigation into the inadvertent start of the turbine driven auxiliary feedwater pump. At approximately 0200 hours on 9/10/2000, operators found the auxiliary feedwater pump operating without the presence of start signal. Steam generator level was being provided by previously started motor driven AFW pumps and operations secured the turbine driven pump. There was no impact from the event on plant refueling preparations and no safety consequence.
"There was no valid AFW start signal in place at the time and plant conditions were not such that a signal was required. Engineering was requested to investigate the event and identified that at about the time of the pump start, maintenance technicians were working in an adjacent part of this rack where the relay believed to have been involved in the actuation is located. A review of the circuit determined that an inadvertent bump of the relay could result in the start of the pump and the independent actuation of turbine driven AFW steam generator level control valves. Based on this information, Operations concluded that based on the preliminary engineering information an invalid start of an ESF train had occurred and declared the event reportable under 10 CFR 50.72(b)(2)(ii) and 50.73(a)(2)(iv).
"At the time the pump was found in operation it was known that there was no valid start signal, but it was thought that the issue involved only a single component. Because other S/G level maneuvers were in process independent of the AFW start, it was not recognized at the time that the level control valves were involved in the event. After the preliminary engineering review, it was concluded that although it was an invalid actuation, the event involved a train level actuation and was, therefore, reportable."
The NRC resident inspector has been informed of this event by the licensee.
Power Reactor
Event Number: 37303
Facility: CALVERT CLIFFS
Region: 1 State: MD
Unit: [1] [] []
RX Type: [1] CE,[2] CE
NRC Notified By: ROBERT PACE
HQ OPS Officer: BOB STRANSKY
Region: 1 State: MD
Unit: [1] [] []
RX Type: [1] CE,[2] CE
NRC Notified By: ROBERT PACE
HQ OPS Officer: BOB STRANSKY
Notification Date: 09/10/2000
Notification Time: 23:02 [ET]
Event Date: 09/10/2000
Event Time: 21:23 [EDT]
Last Update Date: 09/11/2000
Notification Time: 23:02 [ET]
Event Date: 09/10/2000
Event Time: 21:23 [EDT]
Last Update Date: 09/11/2000
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
10 CFR Section:
50.72(b)(2)(ii) - RPS ACTUATION
Person (Organization):
ANTHONY DIMITRIADIS (R1)
ANTHONY DIMITRIADIS (R1)
| 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 |
AUTOMATIC REACTOR TRIP DUE TO CLOSURE OF MAIN STEAM ISOLATION VALVES
An automatic reactor trip/turbine trip occurred due to the spurious closure of both main steam isolation valves (MSIVs). The spurious MSIV closure was the result of a failed logic module in the engineered safety features actuation system (ESFAS). All control rods inserted following the trip, and all systems functioned as expected. The auxiliary feedwater (AFW) system automatically started as designed following the trip. The unit is currently stable in Hot Standby with decay heat being removed through steam released via the steam generator atmospheric dump valves. Steam generator water levels are being maintained by the AFW system.
The licensee anticipates that replacement of the logic module and establishment of decay heat removal via the main condenser will occur within the next few hours. The NRC resident inspector has been informed of this event by the licensee. The licensee reported that nearby residents have contacted emergency services regarding the noises caused by the steam release through the atmospheric dump valves. The licensee plans to make a press release regarding this event.
* * * UPDATE 0428EDT ON 9/11/00 FROM ROBERT PACE TO S. SANDIN * * *
The MSIVs were reopened and the main condenser placed back in service at 0420EDT for decay heat removal. Preparations are underway to restore one main feedwater pump and secure the AFW system. Notified R1DO(Dimitriadis).
An automatic reactor trip/turbine trip occurred due to the spurious closure of both main steam isolation valves (MSIVs). The spurious MSIV closure was the result of a failed logic module in the engineered safety features actuation system (ESFAS). All control rods inserted following the trip, and all systems functioned as expected. The auxiliary feedwater (AFW) system automatically started as designed following the trip. The unit is currently stable in Hot Standby with decay heat being removed through steam released via the steam generator atmospheric dump valves. Steam generator water levels are being maintained by the AFW system.
The licensee anticipates that replacement of the logic module and establishment of decay heat removal via the main condenser will occur within the next few hours. The NRC resident inspector has been informed of this event by the licensee. The licensee reported that nearby residents have contacted emergency services regarding the noises caused by the steam release through the atmospheric dump valves. The licensee plans to make a press release regarding this event.
* * * UPDATE 0428EDT ON 9/11/00 FROM ROBERT PACE TO S. SANDIN * * *
The MSIVs were reopened and the main condenser placed back in service at 0420EDT for decay heat removal. Preparations are underway to restore one main feedwater pump and secure the AFW system. Notified R1DO(Dimitriadis).