Event Notification Report for March 21, 1999
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
03/20/1999 - 03/21/1999
Power Reactor
Event Number: 35495
Facility: DRESDEN
Region: 3 State: IL
Unit: [] [2] []
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: MATTSON
HQ OPS Officer: CHAUNCEY GOULD
Region: 3 State: IL
Unit: [] [2] []
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: MATTSON
HQ OPS Officer: CHAUNCEY GOULD
Notification Date: 03/21/1999
Notification Time: 05:18 [ET]
Event Date: 03/21/1999
Event Time: 03:30 [CST]
Last Update Date: 03/21/1999
Notification Time: 05:18 [ET]
Event Date: 03/21/1999
Event Time: 03:30 [CST]
Last Update Date: 03/21/1999
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(2)(iii)(D) - ACCIDENT MITIGATION
10 CFR Section:
50.72(b)(2)(iii)(D) - ACCIDENT MITIGATION
Person (Organization):
GEOFFREY WRIGHT (R3)
GEOFFREY WRIGHT (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | Y | 99 | Power Operation | 99 | Power Operation |
ROD BLOCK MONITORS 7&8 ARE OUT OF SERVICE AND THE PLANT ENTERED AN LCO.
THE ROD BLOCK MONITORS (RBM) WERE FOUND TO HAVE INOPERABLE LPRM COUNT CIRCUITS. DEPENDING ON THE CONTROL ROD SELECTED, BOTH RBM 7&8 DETECTED MORE LPRM INPUTS THAN WERE ACTUALLY PRESENT. WITH THIS CONDITION OCCURRING, THE RBM WOULD NOT PROVIDE THE REQUIRED "INOP" TRIP (ROD BLOCK DUE TO TOO FEW INPUTS). THE HI ROD BLOCK TRIP WAS ALSO NON-CONSERVATIVE SINCE LPRM SIGNALS NOT ASSOCIATED WITH THE SELECTED LPRM STRING ROD GROUP WERE BEING AVERAGED IN WITH THAT GROUP'S NORMAL INPUTS. AS REQUIRED BY THE LCO ACTION STATEMENT, ONE (#8) OF THE RBM CHANNELS WAS TRIPPED AND TAKEN OUT OF SERVICE.
THE RESIDENT INSPECTOR WILL BE NOTIFIED.
THE ROD BLOCK MONITORS (RBM) WERE FOUND TO HAVE INOPERABLE LPRM COUNT CIRCUITS. DEPENDING ON THE CONTROL ROD SELECTED, BOTH RBM 7&8 DETECTED MORE LPRM INPUTS THAN WERE ACTUALLY PRESENT. WITH THIS CONDITION OCCURRING, THE RBM WOULD NOT PROVIDE THE REQUIRED "INOP" TRIP (ROD BLOCK DUE TO TOO FEW INPUTS). THE HI ROD BLOCK TRIP WAS ALSO NON-CONSERVATIVE SINCE LPRM SIGNALS NOT ASSOCIATED WITH THE SELECTED LPRM STRING ROD GROUP WERE BEING AVERAGED IN WITH THAT GROUP'S NORMAL INPUTS. AS REQUIRED BY THE LCO ACTION STATEMENT, ONE (#8) OF THE RBM CHANNELS WAS TRIPPED AND TAKEN OUT OF SERVICE.
THE RESIDENT INSPECTOR WILL BE NOTIFIED.
Power Reactor
Event Number: 35496
Facility: DRESDEN
Region: 3 State: IL
Unit: [] [] [3]
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: HAL DODD
HQ OPS Officer: DOUG WEAVER
Region: 3 State: IL
Unit: [] [] [3]
RX Type: [1] GE-1,[2] GE-3,[3] GE-3
NRC Notified By: HAL DODD
HQ OPS Officer: DOUG WEAVER
Notification Date: 03/21/1999
Notification Time: 12:43 [ET]
Event Date: 03/21/1999
Event Time: 11:38 [CST]
Last Update Date: 03/21/1999
Notification Time: 12:43 [ET]
Event Date: 03/21/1999
Event Time: 11:38 [CST]
Last Update Date: 03/21/1999
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(1)(i)(A) - PLANT S/D REQD BY TS
10 CFR Section:
50.72(b)(1)(i)(A) - PLANT S/D REQD BY TS
Person (Organization):
GEOFFREY WRIGHT (R3)
GEOFFREY WRIGHT (R3)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 3 | N | Y | 38 | Power Operation | 37 | Power Operation |
SHUTDOWN REQUIRED BY TECHNICAL SPECIFICATIONS
The licensee commenced a plant shutdown at 1138 CST because of non-isolable pressure boundary leakage in the 'B' recirculation loop. A drywell entry was initiated due to an increase in the drywell activity reading. A leak was discovered from flow element 3-261-9B tap at a tee in a welded fitting that attaches to the flow venturi. The leak rate is estimated to be 0.25 gpm.
The licensee plans to bring the plant to cold shutdown to make repairs. The plant is expected to come off line at 1400 CST and be in cold shutdown by approximately 1800 CST.
The licensee notified the NRC resident inspector.
The licensee commenced a plant shutdown at 1138 CST because of non-isolable pressure boundary leakage in the 'B' recirculation loop. A drywell entry was initiated due to an increase in the drywell activity reading. A leak was discovered from flow element 3-261-9B tap at a tee in a welded fitting that attaches to the flow venturi. The leak rate is estimated to be 0.25 gpm.
The licensee plans to bring the plant to cold shutdown to make repairs. The plant is expected to come off line at 1400 CST and be in cold shutdown by approximately 1800 CST.
The licensee notified the NRC resident inspector.