Event Notification Report for April 30, 2004
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
04/29/2004 - 04/30/2004
EVENT NUMBERS
40721
Power Reactor
Event Number: 40721
Facility: ARKANSAS NUCLEAR
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: R.H.SCHNEIDER
HQ OPS Officer: JOSEPH TAYLOR
Region: 4 State: AR
Unit: [1] [] []
RX Type: [1] B&W-L-LP,[2] CE
NRC Notified By: R.H.SCHNEIDER
HQ OPS Officer: JOSEPH TAYLOR
Notification Date: 05/03/2004
Notification Time: 15:29 [ET]
Event Date: 04/30/2004
Event Time: 14:38 [CDT]
Last Update Date: 05/03/2004
Notification Time: 15:29 [ET]
Event Date: 04/30/2004
Event Time: 14:38 [CDT]
Last Update Date: 05/03/2004
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):
TOM FARNHOLTZ (R4)
TOM FARNHOLTZ (R4)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | N | N | 0 | Refueling | 0 | Refueling |
"On 4/30/2004, during Refueling Outage 1 R18, ultrasonic testing of the reactor vessel head identified two axial indications on Control Rod Drive Mechanism, nozzle 61. The indications were located on the outside diameter of the nozzle on the lower hillside. One of the flaws was at the toe of the fillet weld and extended below the fillet weld cap. The second flaw extended the full length of the weld and just below the toe of the fillet weld.
"There were no indications that either of the flaws was through-wall or through-weld and both were typical of Primary Water Stress Corrosion Cracking. No formal evaluation of these flaws has been completed; however, based on past analysis it is expected that they would not be found acceptable under ASME standards and, therefore, represent degradation of a principal safety barrier reportable under the referenced criterion. This condition was determined to be reportable at 0839 CDT on 5/3/2004.
"The nozzle will be repaired prior to startup from the current refueling outage.
"The reactor vessel head inspection was subsequently completed with no additional flaws identified."
The licensee notified the NRC Resident Inspector.
"There were no indications that either of the flaws was through-wall or through-weld and both were typical of Primary Water Stress Corrosion Cracking. No formal evaluation of these flaws has been completed; however, based on past analysis it is expected that they would not be found acceptable under ASME standards and, therefore, represent degradation of a principal safety barrier reportable under the referenced criterion. This condition was determined to be reportable at 0839 CDT on 5/3/2004.
"The nozzle will be repaired prior to startup from the current refueling outage.
"The reactor vessel head inspection was subsequently completed with no additional flaws identified."
The licensee notified the NRC Resident Inspector.