Event Notification Report for July 27, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
07/26/2023 - 07/27/2023
EVENT NUMBERS
56643
56643
Non-Power Reactor
Event Number: 56643
Rep Org: Univ Of California Davis McClellan (CALD)
Licensee: United States Air Force
Region: 0
City: Sacramento State: CA
County: Sacramento
License #: R-130
Agreement: Y
Docket: 05000607
NRC Notified By: Wesley Frey
HQ OPS Officer: Bethany Cecere
Licensee: United States Air Force
Region: 0
City: Sacramento State: CA
County: Sacramento
License #: R-130
Agreement: Y
Docket: 05000607
NRC Notified By: Wesley Frey
HQ OPS Officer: Bethany Cecere
Notification Date: 07/28/2023
Notification Time: 15:21 [ET]
Event Date: 07/27/2023
Event Time: 15:00 [PDT]
Last Update Date: 07/28/2023
Notification Time: 15:21 [ET]
Event Date: 07/27/2023
Event Time: 15:00 [PDT]
Last Update Date: 07/28/2023
Emergency Class: Non Emergency
10 CFR Section:
10 CFR Section:
Person (Organization):
Tran, Linh (NRR PM)
Waugh, Andrew (NPR ENC)
Tran, Linh (NRR PM)
Waugh, Andrew (NPR ENC)
FUEL ELEMENT INSPECTION FAILURE
The following information was provided by the licensee via email:
"This notification is being made per the requirements of technical specification 6.7.2
"During the facility's routine 2023 fuel inspection on July 27th, 2023, it was discovered that a stainless steel clad standard TRIGA 20/20 element did not pass its visual inspection. The visual inspection of the element, made via an underwater camera with approximately 2 times optical magnification, showed inward pitting and unusual discoloration in the cladding of the fueled section of the element. The elongation and transverse bend of the element were measured and were within tolerance per the facility's technical specifications. The cause of this pitting is unknown at this time. The element has been permanently retired from service and placed in an in-tank fuel storage rack. No unusual radiation readings were observed leading up to the inspection or during the inspection. Therefore, it is very likely that the integrity of the cladding has not been compromised and no fission products have escaped as a result of the pitting.
"Though not required by the facility's technical specifications, [McClellan Nuclear Research Center] (MNRC) staff is proceeding with the inspection of all adjacent fuel elements and all other standard elements that have not been inspected within the last year. This inspection corresponds to approximately 85% of all in-core elements. The expected completion date of this inspection is August 2nd. Detailed results of this inspection will be provided in an incident report to the NRC no later than August 10, 2023."
The following information was provided by the licensee via email:
"This notification is being made per the requirements of technical specification 6.7.2
"During the facility's routine 2023 fuel inspection on July 27th, 2023, it was discovered that a stainless steel clad standard TRIGA 20/20 element did not pass its visual inspection. The visual inspection of the element, made via an underwater camera with approximately 2 times optical magnification, showed inward pitting and unusual discoloration in the cladding of the fueled section of the element. The elongation and transverse bend of the element were measured and were within tolerance per the facility's technical specifications. The cause of this pitting is unknown at this time. The element has been permanently retired from service and placed in an in-tank fuel storage rack. No unusual radiation readings were observed leading up to the inspection or during the inspection. Therefore, it is very likely that the integrity of the cladding has not been compromised and no fission products have escaped as a result of the pitting.
"Though not required by the facility's technical specifications, [McClellan Nuclear Research Center] (MNRC) staff is proceeding with the inspection of all adjacent fuel elements and all other standard elements that have not been inspected within the last year. This inspection corresponds to approximately 85% of all in-core elements. The expected completion date of this inspection is August 2nd. Detailed results of this inspection will be provided in an incident report to the NRC no later than August 10, 2023."