Event Notification Report for December 16, 2023
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
12/15/2023 - 12/16/2023
Power Reactor
Event Number: 56894
Facility: Grand Gulf
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Mike Riehl
HQ OPS Officer: Dan Livermore
Region: 4 State: MS
Unit: [1] [] []
RX Type: [1] GE-6
NRC Notified By: Mike Riehl
HQ OPS Officer: Dan Livermore
Notification Date: 12/16/2023
Notification Time: 08:22 [ET]
Event Date: 12/16/2023
Event Time: 03:50 [CST]
Last Update Date: 12/18/2023
Notification Time: 08:22 [ET]
Event Date: 12/16/2023
Event Time: 03:50 [CST]
Last Update Date: 12/18/2023
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):
Agrawal, Ami (R4DO)
Agrawal, Ami (R4DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | A/R | Y | 81 | Power Operation | 0 | Hot Shutdown |
EN Revision Imported Date: 12/18/2023
EN Revision Text: AUTOMATIC SCRAM DUE TO TURBINE TRIP
The following information was provided by the licensee via email:
"On December 16, 2023, at 0350 CST, Grand Gulf Nuclear Station was operating in mode 1 at 81 percent power when an automatic scram occurred due to a turbine trip signal. Before the scram the unit was performing a rod sequence exchange, and no critical work was underway. The cause of the turbine trip signal is not known at this time and is being investigated. All control rods fully inserted, there were no complications, and all plant systems responded as designed. Reactor water level is being maintained by main feedwater and condensate. Reactor pressure is being maintained with main turbine bypass valves. No radiological releases have occurred due to this event.
"This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A), as any event or condition that results in actuation of the reactor protection system when the reactor is critical and specified system actuation due to expected reactor water level 3 isolation signals on a reactor scram. The NRC Senior Resident Inspector has been notified of this event."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Group 2 and Group 3 isolations occurred on the Level 3 isolation signal.
EN Revision Text: AUTOMATIC SCRAM DUE TO TURBINE TRIP
The following information was provided by the licensee via email:
"On December 16, 2023, at 0350 CST, Grand Gulf Nuclear Station was operating in mode 1 at 81 percent power when an automatic scram occurred due to a turbine trip signal. Before the scram the unit was performing a rod sequence exchange, and no critical work was underway. The cause of the turbine trip signal is not known at this time and is being investigated. All control rods fully inserted, there were no complications, and all plant systems responded as designed. Reactor water level is being maintained by main feedwater and condensate. Reactor pressure is being maintained with main turbine bypass valves. No radiological releases have occurred due to this event.
"This event is being reported under 10 CFR 50.72(b)(2)(iv)(B) and 10 CFR 50.72(b)(3)(iv)(A), as any event or condition that results in actuation of the reactor protection system when the reactor is critical and specified system actuation due to expected reactor water level 3 isolation signals on a reactor scram. The NRC Senior Resident Inspector has been notified of this event."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
Group 2 and Group 3 isolations occurred on the Level 3 isolation signal.
Agreement State
Event Number: 56895
Rep Org: Illinois Emergency Mgmt. Agency
Licensee: Sterigenics U.S. LLC
Region: 3
City: Gurnee State: IL
County:
License #: IL-01220-01
Agreement: Y
Docket:
NRC Notified By: Gary Foresee
HQ OPS Officer: Brian Lin
Licensee: Sterigenics U.S. LLC
Region: 3
City: Gurnee State: IL
County:
License #: IL-01220-01
Agreement: Y
Docket:
NRC Notified By: Gary Foresee
HQ OPS Officer: Brian Lin
Notification Date: 12/17/2023
Notification Time: 21:31 [ET]
Event Date: 12/16/2023
Event Time: 23:00 [CST]
Last Update Date: 01/26/2024
Notification Time: 21:31 [ET]
Event Date: 12/16/2023
Event Time: 23:00 [CST]
Last Update Date: 01/26/2024
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
McCraw, Aaron (R3DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
McCraw, Aaron (R3DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
EN Revision Imported Date: 1/29/2024
EN Revision Text: AGREEMENT STATE REPORT - STUCK SOURCE RACK
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"The IEMA-OHS Operations Center was contacted at 1712 CDT on December 17, 2023, by the radiation safety officer for Sterigenics to report a stuck source rack. The rack reportedly became stuck around 2300 on December 16, 2023, with approximately 10 percent of the sources above the pool level. The area was isolated with an additional restricted area established to maintain occupational exposures within limits. At this time, no public or occupational exposures above regulatory limits have been reported. This matter has a 24-hour reporting requirement under 32 Ill. Adm. Code 346.830 which was met by the licensee. IEMA-OHS inspectors will arrive at the facility on 12/18 to evaluate timelines for corrective action and the efficacy of safety systems. Staff will also evaluate the site and review staff dosimetry, potential impacts to source capsule integrity, any anticipated heat impacts, and plans for quality assurance of the impacted system(s)."
Source type: sealed source irradiator
Radionuclide: Co-60
Activity: 24 MCi (888 PBq)
Model no.: C-188
Illinois report no.: IL230036
* * * UPDATE ON 12/19/23 FROM WHITNEY COX TO DAN LIVERMORE * * *
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"Agency staff arrived at the site on 12/18/23 and surveys indicate no public or occupational exposure levels above normal operation. The source rack is still stuck in the unshielded position. The Agency continues to monitor the situation and will update when additional information is available."
Notified R3DO (Edwards), NMSS (via email).
* * * UPDATE ON 1/4/24 FROM GARY FORSEE TO IAN HOWARD * * *
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"The Licensee reports 18 modules (3 rows), constituting 626,000 curies of Co-60, in the B/C cell remain stuck in the unshielded position due to product carts impeding travel of the rack. The sources are below the point of product cart impact. A second IEMA-OHS inspection was conducted to increase coordination on response activities and obtain additional data on the following: security requirements (all operational), radiation levels (700 microR/hour maximum reading), dosimetry procedures (transitioned to digital dosimetry which is read daily and employed at a 40 mrem/day investigational level), total occupational doses to date (20 mrem), exposure rate maps including access points used for radiation hardened cameras, personnel access, pool conductivity (within specifications), updated operations and emergency procedures (confirmed), on site staff and safety culture (satisfactory, additional manufacturer health physics staff brought in to assist), fire hazards (none at this time), status of deionizer (satisfactory), and mitigation planning.
"The Licensee is awaiting cameras and remote vehicles capable of withstanding radiation levels and manipulating product totes. The facility was confirmed to be in a safe and stable condition and ongoing response operations will be coordinated with IEMA-OHS. IEMA-OHS has now transitioned to weekly inspections until the incident is remedied.
"Updates will be provided as they become available."
Notified R3DO (Stoedter), NMSS (via email).
* * * UPDATE ON 01/26/24 FROM GARY FORSEE TO THOMAS HERRITY * * *
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"The source rack was successfully returned to the shielded position. Sterigenics staff employed engineered tooling to access the stuck rack through roof projections on the evening of 1/25/24. IEMA-OHS staff were on site to observe setup and operations throughout the week. A review of digital dosimetry in use for all phases of the operations indicates there were no occupational exposures in excess of regulatory limits.
"Full report and root cause analysis pending. This report will be updated."
Notified R3DO (Orlikowski), NMSS (via email).
EN Revision Text: AGREEMENT STATE REPORT - STUCK SOURCE RACK
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"The IEMA-OHS Operations Center was contacted at 1712 CDT on December 17, 2023, by the radiation safety officer for Sterigenics to report a stuck source rack. The rack reportedly became stuck around 2300 on December 16, 2023, with approximately 10 percent of the sources above the pool level. The area was isolated with an additional restricted area established to maintain occupational exposures within limits. At this time, no public or occupational exposures above regulatory limits have been reported. This matter has a 24-hour reporting requirement under 32 Ill. Adm. Code 346.830 which was met by the licensee. IEMA-OHS inspectors will arrive at the facility on 12/18 to evaluate timelines for corrective action and the efficacy of safety systems. Staff will also evaluate the site and review staff dosimetry, potential impacts to source capsule integrity, any anticipated heat impacts, and plans for quality assurance of the impacted system(s)."
Source type: sealed source irradiator
Radionuclide: Co-60
Activity: 24 MCi (888 PBq)
Model no.: C-188
Illinois report no.: IL230036
* * * UPDATE ON 12/19/23 FROM WHITNEY COX TO DAN LIVERMORE * * *
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"Agency staff arrived at the site on 12/18/23 and surveys indicate no public or occupational exposure levels above normal operation. The source rack is still stuck in the unshielded position. The Agency continues to monitor the situation and will update when additional information is available."
Notified R3DO (Edwards), NMSS (via email).
* * * UPDATE ON 1/4/24 FROM GARY FORSEE TO IAN HOWARD * * *
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"The Licensee reports 18 modules (3 rows), constituting 626,000 curies of Co-60, in the B/C cell remain stuck in the unshielded position due to product carts impeding travel of the rack. The sources are below the point of product cart impact. A second IEMA-OHS inspection was conducted to increase coordination on response activities and obtain additional data on the following: security requirements (all operational), radiation levels (700 microR/hour maximum reading), dosimetry procedures (transitioned to digital dosimetry which is read daily and employed at a 40 mrem/day investigational level), total occupational doses to date (20 mrem), exposure rate maps including access points used for radiation hardened cameras, personnel access, pool conductivity (within specifications), updated operations and emergency procedures (confirmed), on site staff and safety culture (satisfactory, additional manufacturer health physics staff brought in to assist), fire hazards (none at this time), status of deionizer (satisfactory), and mitigation planning.
"The Licensee is awaiting cameras and remote vehicles capable of withstanding radiation levels and manipulating product totes. The facility was confirmed to be in a safe and stable condition and ongoing response operations will be coordinated with IEMA-OHS. IEMA-OHS has now transitioned to weekly inspections until the incident is remedied.
"Updates will be provided as they become available."
Notified R3DO (Stoedter), NMSS (via email).
* * * UPDATE ON 01/26/24 FROM GARY FORSEE TO THOMAS HERRITY * * *
The following information was received from the Illinois Emergency Management Agency (IEMA-OHS) via email:
"The source rack was successfully returned to the shielded position. Sterigenics staff employed engineered tooling to access the stuck rack through roof projections on the evening of 1/25/24. IEMA-OHS staff were on site to observe setup and operations throughout the week. A review of digital dosimetry in use for all phases of the operations indicates there were no occupational exposures in excess of regulatory limits.
"Full report and root cause analysis pending. This report will be updated."
Notified R3DO (Orlikowski), NMSS (via email).