Event Notification Report for April 10, 2001
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/09/2001 - 04/10/2001
Power Reactor
Event Number: 37907
Facility: CALLAWAY
Region: 4 State: MO
Unit: [1] [] []
RX Type: [1] W-4-LP
NRC Notified By: SCOT MAGLIO
HQ OPS Officer: FANGIE JONES
Region: 4 State: MO
Unit: [1] [] []
RX Type: [1] W-4-LP
NRC Notified By: SCOT MAGLIO
HQ OPS Officer: FANGIE JONES
Notification Date: 04/11/2001
Notification Time: 05:55 [ET]
Event Date: 04/10/2001
Event Time: 19:50 [CDT]
Last Update Date: 04/11/2001
Notification Time: 05:55 [ET]
Event Date: 04/10/2001
Event Time: 19:50 [CDT]
Last Update Date: 04/11/2001
Emergency Class: NON EMERGENCY
10 CFR Section:
73.71(b)(1) - SAFEGUARDS REPORTS
10 CFR Section:
73.71(b)(1) - SAFEGUARDS REPORTS
Person (Organization):
MARK SHAFFER (R4)
MARK SHAFFER (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
SECURITY REPORT
Safeguards system degradation related to monitoring. Immediate compensatory measures taken upon discovery.
The licensee intends to notify the NRC Resident Inspector.
Refer to the HOO Log for additional details.
Safeguards system degradation related to monitoring. Immediate compensatory measures taken upon discovery.
The licensee intends to notify the NRC Resident Inspector.
Refer to the HOO Log for additional details.
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
!!!!! THIS EVENT HAS BEEN RETRACTED !!!!!
Power Reactor
Event Number: 37905
Facility: ROBINSON
Region: 2 State: SC
Unit: [2] [] []
RX Type: [2] W-3-LP
NRC Notified By: HAROLD CHERNOFF
HQ OPS Officer: LEIGH TROCINE
Region: 2 State: SC
Unit: [2] [] []
RX Type: [2] W-3-LP
NRC Notified By: HAROLD CHERNOFF
HQ OPS Officer: LEIGH TROCINE
Notification Date: 04/10/2001
Notification Time: 18:49 [ET]
Event Date: 04/10/2001
Event Time: 13:30 [EDT]
Last Update Date: 04/18/2001
Notification Time: 18:49 [ET]
Event Date: 04/10/2001
Event Time: 13:30 [EDT]
Last Update Date: 04/18/2001
Emergency Class: NON EMERGENCY
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
10 CFR Section:
50.72(b)(3)(ii)(A) - DEGRADED CONDITION
Person (Organization):
MIKE ERNSTES (R2)
MIKE ERNSTES (R2)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 2 | N | N | 0 | Cold Shutdown | 0 | Cold Shutdown |
DISCOVERY OF REACTOR COOLANT SYSTEM PRESSURE BOUNDARY LEAKAGE POSSIBLY VIA A CONTROL ROD DRIVE MECHANISM ASSEMBLY SEAL WELD
The following text is a portion of a facsimile received from the licensee:
"On 4/10/01, during the removal of mirror insulation from the reactor vessel head while shut down, deposits of residual boric acid were found on the periphery of the Reactor Pressure Vessel Head outside of the Control Rod Drive Mechanism (CRDM) Shroud. Subsequent investigation, by visual inspection of the area within the shroud, revealed additional amounts of boric acid. The source of the leak, based on initial observation, appears to be a CRDM assembly seal-weld leak about 18 inches above the vessel head insulation. A leak from this location would constitute Reactor Coolant System Pressure Boundary leakage. Initial inspection of the reactor vessel head areas, in the vicinity of the boric acid deposits outside of the shroud, revealed no damage to the reactor vessel head."
The licensee notified the NRC resident inspector.
* * * UPDATE ON 04/18/01 @ 1123 BY GARROU TO GOULD * * * RETRACTION
On 4/10/01, during the removal of mirror insulation from the reactor vessel head while shut down.
deposits of residual boric acid crystals were found on the periphery of the Reactor Pressure Vessel
Head outside of the Control Rod Drive Mechanism (CRDM) shroud. Subsequent inspection at CRDM canopy seal welds and the reactor vessel head in the vicinity of the boric acid crystal deposits was conducted with the head off the reactor vessel and the shroud and some mirror insulation removed. The identified source of the observed boric acid crystals was two very small locations on the canopy seal weld of CRDM No. 68 at location B10.
Leakage through the canopy seal weld is not pressure boundary leakage as described in the Technical Specifications and Bases. The structural integrity of the CRDM housing is maintained by the threaded connection. The canopy seal weld does not maintain the structural integrity of the reactor coolant system. Therefore, the original notification made pursuant to 10CFR 50.72(b)(3)(ii)(A) is retracted.
The NRC Resident Inspector was notified.
Reg 2 RDO(Landis) was notified.
The following text is a portion of a facsimile received from the licensee:
"On 4/10/01, during the removal of mirror insulation from the reactor vessel head while shut down, deposits of residual boric acid were found on the periphery of the Reactor Pressure Vessel Head outside of the Control Rod Drive Mechanism (CRDM) Shroud. Subsequent investigation, by visual inspection of the area within the shroud, revealed additional amounts of boric acid. The source of the leak, based on initial observation, appears to be a CRDM assembly seal-weld leak about 18 inches above the vessel head insulation. A leak from this location would constitute Reactor Coolant System Pressure Boundary leakage. Initial inspection of the reactor vessel head areas, in the vicinity of the boric acid deposits outside of the shroud, revealed no damage to the reactor vessel head."
The licensee notified the NRC resident inspector.
* * * UPDATE ON 04/18/01 @ 1123 BY GARROU TO GOULD * * * RETRACTION
On 4/10/01, during the removal of mirror insulation from the reactor vessel head while shut down.
deposits of residual boric acid crystals were found on the periphery of the Reactor Pressure Vessel
Head outside of the Control Rod Drive Mechanism (CRDM) shroud. Subsequent inspection at CRDM canopy seal welds and the reactor vessel head in the vicinity of the boric acid crystal deposits was conducted with the head off the reactor vessel and the shroud and some mirror insulation removed. The identified source of the observed boric acid crystals was two very small locations on the canopy seal weld of CRDM No. 68 at location B10.
Leakage through the canopy seal weld is not pressure boundary leakage as described in the Technical Specifications and Bases. The structural integrity of the CRDM housing is maintained by the threaded connection. The canopy seal weld does not maintain the structural integrity of the reactor coolant system. Therefore, the original notification made pursuant to 10CFR 50.72(b)(3)(ii)(A) is retracted.
The NRC Resident Inspector was notified.
Reg 2 RDO(Landis) was notified.