Event Notification Report for May 24, 2022
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/23/2022 - 05/24/2022
Power Reactor
Event Number: 55910
Facility: Cook
Region: 3 State: MI
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Richard Harris
HQ OPS Officer: Brian Lin
Region: 3 State: MI
Unit: [1] [] []
RX Type: [1] W-4-LP,[2] W-4-LP
NRC Notified By: Richard Harris
HQ OPS Officer: Brian Lin
Notification Date: 05/24/2022
Notification Time: 06:49 [ET]
Event Date: 05/24/2022
Event Time: 04:14 [EDT]
Last Update Date: 05/24/2022
Notification Time: 06:49 [ET]
Event Date: 05/24/2022
Event Time: 04:14 [EDT]
Last Update Date: 05/24/2022
Emergency Class: Non Emergency
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
10 CFR Section:
50.72(b)(2)(iv)(B) - RPS Actuation - Critical 50.72(b)(3)(iv)(A) - Valid Specif Sys Actuation
Person (Organization):
Lafranzo, Michael (R3DO)
Lafranzo, Michael (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 12 | Power Operation | 0 | Hot Standby |
EN Revision Imported Date: 5/25/2022
EN Revision Text: MANUAL REACTOR TRIP FOLLOWING MANUAL TURBINE TRIP FROM HIGH VIBRATIONS ON MAIN TURBINE
The following information was provided by the licensee via email:
"On May 24, 2022, at 0414 EDT, while rolling the Unit 1 main turbine during the Unit 1 Cycle 31 refueling outage, the Unit 1 main turbine experienced high vibrations and the main turbine was manually tripped with reactor power at 12 percent. Main turbine vibrations persisted and the reactor was manually tripped, Main Steam Stop Valves were closed, and main condenser vacuum was broken.
"This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The DC Cook Resident NRC Inspector has been notified.
"Unit 1 is being supplied by offsite power. All control rods fully inserted. Both Motor Driven Auxiliary Feedwater Pumps started properly. Decay heat is being removed via Steam Generator Power Operated Relief Valves. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 1 remains stable in Mode 3 while conducting the Post Trip Review. No radioactive release is in progress as a result of this event."
EN Revision Text: MANUAL REACTOR TRIP FOLLOWING MANUAL TURBINE TRIP FROM HIGH VIBRATIONS ON MAIN TURBINE
The following information was provided by the licensee via email:
"On May 24, 2022, at 0414 EDT, while rolling the Unit 1 main turbine during the Unit 1 Cycle 31 refueling outage, the Unit 1 main turbine experienced high vibrations and the main turbine was manually tripped with reactor power at 12 percent. Main turbine vibrations persisted and the reactor was manually tripped, Main Steam Stop Valves were closed, and main condenser vacuum was broken.
"This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), Reactor Protection System (RPS) actuation as a four (4) hour report, and under 10 CFR 50.72(b)(3)(iv)(A), specified system actuation of the Auxiliary Feedwater System, as an eight (8) hour report. The DC Cook Resident NRC Inspector has been notified.
"Unit 1 is being supplied by offsite power. All control rods fully inserted. Both Motor Driven Auxiliary Feedwater Pumps started properly. Decay heat is being removed via Steam Generator Power Operated Relief Valves. Preliminary evaluation indicates all plant systems functioned normally following the Reactor Trip. DC Cook Unit 1 remains stable in Mode 3 while conducting the Post Trip Review. No radioactive release is in progress as a result of this event."
Non-Power Reactor
Event Number: 55914
Rep Org: Univ Of Utah (UTAT)
Licensee: University Of Utah
Region: 0
City: Salt Lake City State: UT
County: Salt Lake
License #: R-126
Agreement: Y
Docket: 05000407
NRC Notified By: Glenn E. Sjoden
HQ OPS Officer: Karen Cotton-Gross
Licensee: University Of Utah
Region: 0
City: Salt Lake City State: UT
County: Salt Lake
License #: R-126
Agreement: Y
Docket: 05000407
NRC Notified By: Glenn E. Sjoden
HQ OPS Officer: Karen Cotton-Gross
Notification Date: 05/24/2022
Notification Time: 18:00 [ET]
Event Date: 05/24/2022
Event Time: 11:15 [MDT]
Last Update Date: 05/24/2022
Notification Time: 18:00 [ET]
Event Date: 05/24/2022
Event Time: 11:15 [MDT]
Last Update Date: 05/24/2022
Emergency Class: Non Emergency
10 CFR Section:
10 CFR Section:
Person (Organization):
Yin, Xiasong (PM)
Takacs,Michael (NPR CO )
Yin, Xiasong (PM)
Takacs,Michael (NPR CO )
DEGRADATION TO A FUEL ELEMENT CLADDING
The following information was provided by the University Of Utah Training Reactor (UUTR) via email:
"This is a written report to NRC regarding minor damage to a fuel element identified during routine fuel inspection operations, filed per UUTR Technical Specification para 6.7.2, 'Special Reports' noting degradation in a reactor fuel element cladding. On Tuesday, May 24 2022, at 1115 [MDT], during a routine UUTR bi-annual fuel inspection, one stainless steel U-235 TRIGA fuel element removed from core position D-14, element number 4138E, was noted to have low-level surface pitting and severe discoloration at several locations along the element length. When this fuel element was moved toward the inspection apparatus, at one of the pitted locations on the surface of the fuel element, a small stream of clear bubbles began to evolve. This was captured on high resolution video; the bubbles were presumed to be fission gas. Reinspection of this same fuel element one hour later with high resolution video showed no evolution of gas bubbles, and the element remained intact. Radiation levels throughout the facility remained constant and consistent with background levels.
"Response to this Event: After initial observation of the pitting and bubble evolution, the fuel element number 4138E was placed in a fuel element storage rack; local radiation levels remained at measured background levels at all times from multiple instruments. On the facility continuous air monitor, no noted deviations from background levels were observed over the entire period of concern. Radiation readings throughout the duration of this observation remained at background levels, and no significant issues or safety concerns were noted; the reactor and facility remain secure, and fuel inspection operations will continue over the next week.
"Follow-up Actions: UUTR reactor personnel will permanently remove fuel element number 4138E from service, and continue to monitor for any instance of elevated radiation levels from the reactor pool. All levels remain stable at background levels."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The Non-Power Reactor Project Manager will be notified and the Utah State Radiation Safety Officer was notified.
The estimated time for restart is one week.
The following information was provided by the University Of Utah Training Reactor (UUTR) via email:
"This is a written report to NRC regarding minor damage to a fuel element identified during routine fuel inspection operations, filed per UUTR Technical Specification para 6.7.2, 'Special Reports' noting degradation in a reactor fuel element cladding. On Tuesday, May 24 2022, at 1115 [MDT], during a routine UUTR bi-annual fuel inspection, one stainless steel U-235 TRIGA fuel element removed from core position D-14, element number 4138E, was noted to have low-level surface pitting and severe discoloration at several locations along the element length. When this fuel element was moved toward the inspection apparatus, at one of the pitted locations on the surface of the fuel element, a small stream of clear bubbles began to evolve. This was captured on high resolution video; the bubbles were presumed to be fission gas. Reinspection of this same fuel element one hour later with high resolution video showed no evolution of gas bubbles, and the element remained intact. Radiation levels throughout the facility remained constant and consistent with background levels.
"Response to this Event: After initial observation of the pitting and bubble evolution, the fuel element number 4138E was placed in a fuel element storage rack; local radiation levels remained at measured background levels at all times from multiple instruments. On the facility continuous air monitor, no noted deviations from background levels were observed over the entire period of concern. Radiation readings throughout the duration of this observation remained at background levels, and no significant issues or safety concerns were noted; the reactor and facility remain secure, and fuel inspection operations will continue over the next week.
"Follow-up Actions: UUTR reactor personnel will permanently remove fuel element number 4138E from service, and continue to monitor for any instance of elevated radiation levels from the reactor pool. All levels remain stable at background levels."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
The Non-Power Reactor Project Manager will be notified and the Utah State Radiation Safety Officer was notified.
The estimated time for restart is one week.