Event Notification Report for May 19, 2025
U.S. Nuclear Regulatory Commission
Operations Center
EVENT REPORTS FOR
05/18/2025 - 05/19/2025
Agreement State
Event Number: 57719
Rep Org: WA Office of Radiation Protection
Licensee: Energy Northwest Environmental Services Laboratory
Region: 4
City: Richland State: WA
County:
License #: WN-L0217-1
Agreement: Y
Docket:
NRC Notified By: Dane Blakinger
HQ OPS Officer: Robert A. Thompson
Licensee: Energy Northwest Environmental Services Laboratory
Region: 4
City: Richland State: WA
County:
License #: WN-L0217-1
Agreement: Y
Docket:
NRC Notified By: Dane Blakinger
HQ OPS Officer: Robert A. Thompson
Notification Date: 05/19/2025
Notification Time: 16:48 [ET]
Event Date: 05/19/2025
Event Time: 09:39 [PDT]
Last Update Date: 06/18/2025
Notification Time: 16:48 [ET]
Event Date: 05/19/2025
Event Time: 09:39 [PDT]
Last Update Date: 06/18/2025
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
Josey, Jeffrey (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
ILTAB, (EMAIL) (EMAIL)
CNSC (Canada) (EMAIL)
Josey, Jeffrey (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
ILTAB, (EMAIL) (EMAIL)
CNSC (Canada) (EMAIL)
EN Revision Imported Date: 6/20/2025
EN Revision Text: AGREEMENT STATE REPORT - LOST SOURCES
The following information was provided by the Washington State Department of Health (the Department) via email:
"On 5/19/2025, at 0939 PDT, the Department was notified of missing or lost sources meeting the reporting criteria of WAC-246-221-240. During a routine inventory, the [licensee's] radiation safety officer (RSO) identified the following missing sources.
"The RSO believes that the sources may have been disposed of appropriately but not removed from the inventory list. A full report is required within 30 days."
Sources:
Am-241, 0.148177 microcuries
Am-241, 0.004437 microcuries
Pu-238, 0.003889 microcuries
Pu-239, 0.004149 microcuries
Th-230, 0.001101 microcuries
WA incident number: WA-25-007
* * * UPDATE ON 6/18/2025 AT 2102 EDT FROM RYAN DRAGNESS TO ERNEST WEST * * *
The following information was provided by the Washington State Department of Health (the Department) via email:
"The [licensee's] radiation safety officer RSO identified the following missing sources.
"Two 47mm air filter (AF) multinuclide calibration standards:
"Source ID 101808: Activity of 6.6E-08 Ci (as of 5/14/25)
"Source ID 107884: Activity of 7.6E-08 Ci (as of 5/14/25)
"Two charcoal cartridge multinuclide calibration standards:
"Source ID 101809: Activity of 6.6E-08 Ci (as of 5/14/25)
"Source ID 107885: Activity of 7.7E-08 Ci (as of 5/14/25)
"Total quantity of Am-241 from the above sources is 0.148177 microcuries
"Additionally, some ERA proficiency study samples, with an activity of approximately 2.38E-07 Ci (as of 5/14/25), were also determined to be missing.
"ERA isotopes whose quantity meet reportable criteria as follows:
"Am-241, 0.004437 microcuries.
"Pu-238, 0.003889 microcuries.
"Pu-239, 0.004149 microcuries.
"Th-230, 0.001101 microcuries.
"The last documented inventory conducted in March 2022 confirmed the presence of these sources. However, during the March 2024 inventory check, it was noted that they were not listed in the tracking spreadsheet. Staff turnover has occurred since the last confirmed inventory, and a review of disposal records did not reveal relevant documentation regarding their whereabouts. A retired employee indicated that if the sources were no longer present, they were likely disposed of at Columbia Generating Station (CGS) chemistry lab without formal documentation.
"Based on information gathered, it is highly probable that the missing sources were disposed of at the CGS chemistry lab without documentation. This conclusion is based on the following:
"Conducted a thorough review of historical disposal records from CGS to identify any undocumented transfers. No additional information was found in disposal records.
"Interviewed current and former CGS personnel involved in material handling and determined the disposal procedures were not followed.
"Reviewed facility waste tracking logs to identify any unintentional misclassification or disposal records of the missing sources. No additional information was found in waste tracking logs.
"Coordinated with CGS radwaste transportation personnel to determine if any retained samples match the description of the lost sources. None of the retained samples matched the description of the lost sources.
"At this time, there are no known exposures of individuals to radiation as a result of the missing sources. Based on an evaluation of the activity levels and potential exposure scenarios, the estimated total effective dose equivalent remains within regulatory limits established by the Washington Administrative Code (WAC) and federal standards. Specifically, the missing sources contain low-activity calibration materials, and potential exposure to members of the public would be well below the annual dose limit of 100 millirem (1 millisievert) set by WAC 246-221-060 for individuals in unrestricted areas. Furthermore, occupational exposure for radiation workers is regulated at 5,000 millirem (50 millisieverts) per year, and no staff have reported any abnormal readings in personnel dosimetry records within our department.
"Ongoing environmental monitoring and workplace surveys have not indicated any elevated radiation levels in laboratory spaces or disposal sites. These findings support the conclusion that the risk of exposure remains negligible, and all radiation safety protocols continue to be in full compliance with state and federal guidelines.
"Since the initial report of missing sources on 5/19/2025, the licensee has performed the following in order to locate the missing radioactive material:
"1. Conducted a thorough review of historical disposal records from CGS to identify any undocumented transfers. No additional information was found in disposal records.
"2. Interviewed current and former CGS personnel involved in material handling and determined the disposal procedures were not followed.
"3. Reviewed facility waste tracking logs to identify any unintentional misclassification or disposal records of the missing sources. No additional information was found in waste tracking logs.
"4. Coordinated with CGS radioactive waste transportation personnel to determine if any retained samples match the description of the lost sources. None of the retained samples matched the description of the lost sources.
"In order to prevent a recurrence, the licensee has implemented the following:
"1. Implement enhanced documentation practices for inventory tracking to include supervisor review.
"2. Improve training for personnel handling radioactive materials.
"3. Strengthen disposal record keeping to ensure formal documentation where approval from supervisor is required.
"4. Incorporation of incident report WA 25-007 as a reference for operating experience to be included in employee training.
"Corrective actions may be incorporated into the Radioactive Materials License. All corrective actions will be verified by the agreement state at the next routine inspection."
Notified R4DO (Drake), NMSS Event Notification (email), ILTAB (email), and CNSC (email)
THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf
EN Revision Text: AGREEMENT STATE REPORT - LOST SOURCES
The following information was provided by the Washington State Department of Health (the Department) via email:
"On 5/19/2025, at 0939 PDT, the Department was notified of missing or lost sources meeting the reporting criteria of WAC-246-221-240. During a routine inventory, the [licensee's] radiation safety officer (RSO) identified the following missing sources.
"The RSO believes that the sources may have been disposed of appropriately but not removed from the inventory list. A full report is required within 30 days."
Sources:
Am-241, 0.148177 microcuries
Am-241, 0.004437 microcuries
Pu-238, 0.003889 microcuries
Pu-239, 0.004149 microcuries
Th-230, 0.001101 microcuries
WA incident number: WA-25-007
* * * UPDATE ON 6/18/2025 AT 2102 EDT FROM RYAN DRAGNESS TO ERNEST WEST * * *
The following information was provided by the Washington State Department of Health (the Department) via email:
"The [licensee's] radiation safety officer RSO identified the following missing sources.
"Two 47mm air filter (AF) multinuclide calibration standards:
"Source ID 101808: Activity of 6.6E-08 Ci (as of 5/14/25)
"Source ID 107884: Activity of 7.6E-08 Ci (as of 5/14/25)
"Two charcoal cartridge multinuclide calibration standards:
"Source ID 101809: Activity of 6.6E-08 Ci (as of 5/14/25)
"Source ID 107885: Activity of 7.7E-08 Ci (as of 5/14/25)
"Total quantity of Am-241 from the above sources is 0.148177 microcuries
"Additionally, some ERA proficiency study samples, with an activity of approximately 2.38E-07 Ci (as of 5/14/25), were also determined to be missing.
"ERA isotopes whose quantity meet reportable criteria as follows:
"Am-241, 0.004437 microcuries.
"Pu-238, 0.003889 microcuries.
"Pu-239, 0.004149 microcuries.
"Th-230, 0.001101 microcuries.
"The last documented inventory conducted in March 2022 confirmed the presence of these sources. However, during the March 2024 inventory check, it was noted that they were not listed in the tracking spreadsheet. Staff turnover has occurred since the last confirmed inventory, and a review of disposal records did not reveal relevant documentation regarding their whereabouts. A retired employee indicated that if the sources were no longer present, they were likely disposed of at Columbia Generating Station (CGS) chemistry lab without formal documentation.
"Based on information gathered, it is highly probable that the missing sources were disposed of at the CGS chemistry lab without documentation. This conclusion is based on the following:
"Conducted a thorough review of historical disposal records from CGS to identify any undocumented transfers. No additional information was found in disposal records.
"Interviewed current and former CGS personnel involved in material handling and determined the disposal procedures were not followed.
"Reviewed facility waste tracking logs to identify any unintentional misclassification or disposal records of the missing sources. No additional information was found in waste tracking logs.
"Coordinated with CGS radwaste transportation personnel to determine if any retained samples match the description of the lost sources. None of the retained samples matched the description of the lost sources.
"At this time, there are no known exposures of individuals to radiation as a result of the missing sources. Based on an evaluation of the activity levels and potential exposure scenarios, the estimated total effective dose equivalent remains within regulatory limits established by the Washington Administrative Code (WAC) and federal standards. Specifically, the missing sources contain low-activity calibration materials, and potential exposure to members of the public would be well below the annual dose limit of 100 millirem (1 millisievert) set by WAC 246-221-060 for individuals in unrestricted areas. Furthermore, occupational exposure for radiation workers is regulated at 5,000 millirem (50 millisieverts) per year, and no staff have reported any abnormal readings in personnel dosimetry records within our department.
"Ongoing environmental monitoring and workplace surveys have not indicated any elevated radiation levels in laboratory spaces or disposal sites. These findings support the conclusion that the risk of exposure remains negligible, and all radiation safety protocols continue to be in full compliance with state and federal guidelines.
"Since the initial report of missing sources on 5/19/2025, the licensee has performed the following in order to locate the missing radioactive material:
"1. Conducted a thorough review of historical disposal records from CGS to identify any undocumented transfers. No additional information was found in disposal records.
"2. Interviewed current and former CGS personnel involved in material handling and determined the disposal procedures were not followed.
"3. Reviewed facility waste tracking logs to identify any unintentional misclassification or disposal records of the missing sources. No additional information was found in waste tracking logs.
"4. Coordinated with CGS radioactive waste transportation personnel to determine if any retained samples match the description of the lost sources. None of the retained samples matched the description of the lost sources.
"In order to prevent a recurrence, the licensee has implemented the following:
"1. Implement enhanced documentation practices for inventory tracking to include supervisor review.
"2. Improve training for personnel handling radioactive materials.
"3. Strengthen disposal record keeping to ensure formal documentation where approval from supervisor is required.
"4. Incorporation of incident report WA 25-007 as a reference for operating experience to be included in employee training.
"Corrective actions may be incorporated into the Radioactive Materials License. All corrective actions will be verified by the agreement state at the next routine inspection."
Notified R4DO (Drake), NMSS Event Notification (email), ILTAB (email), and CNSC (email)
THIS MATERIAL EVENT CONTAINS A 'Less than Cat 3' LEVEL OF RADIOACTIVE MATERIAL
Sources that are "Less than IAEA Category 3 sources," are either sources that are very unlikely to cause permanent injury to individuals or contain a very small amount of radioactive material that would not cause any permanent injury. Some of these sources, such as moisture density gauges or thickness gauges that are Category 4, the amount of unshielded radioactive material, if not safely managed or securely protected, could possibly - although it is unlikely - temporarily injure someone who handled it or were otherwise in contact with it, or who were close to it for a period of many weeks. For additional information go to http://www-pub.iaea.org/MTCD/publications/PDF/Pub1227_web.pdf
Agreement State
Event Number: 57721
Rep Org: Utah Division of Radiation Control
Licensee: EnergySolutions
Region: 4
City: Clive State: UT
County:
License #: UT 2300249
Agreement: Y
Docket:
NRC Notified By: Larry Kellum
HQ OPS Officer: Robert A. Thompson
Licensee: EnergySolutions
Region: 4
City: Clive State: UT
County:
License #: UT 2300249
Agreement: Y
Docket:
NRC Notified By: Larry Kellum
HQ OPS Officer: Robert A. Thompson
Notification Date: 05/19/2025
Notification Time: 18:43 [ET]
Event Date: 05/19/2025
Event Time: 10:30 [MDT]
Last Update Date: 05/19/2025
Notification Time: 18:43 [ET]
Event Date: 05/19/2025
Event Time: 10:30 [MDT]
Last Update Date: 05/19/2025
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
Josey, Jeffrey (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Josey, Jeffrey (R4DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
AGREEMENT STATE REPORT - EXTERNAL RADIATION LEVEL ON SHIPMENT EXCEEDED LIMITS
The following information was provided by the Utah Division of Waste Management and Radiation Control (the Division) via email:
"Shipment 9075-01-0074 arrived at EnergySolutions' Clive disposal facility on May 19, 2025. As Division inspectors were performing incoming waste shipment inspections, [Division] staff surveyed and observed a trailer that exhibited a dose rate of 10.5 mrem/hour at 2 meters from the outer plane of the conveyance. Upon this discovery, the [Division] inspector informed EnergySolutions' shipping and receiving staff of the discrepancy, [who] indicated that they were already aware of said discrepancy.
"The transport vehicle is a curtain-side, flatbed trailer."
Additional license number UT 2300478.
Utah event report ID: UT 25001
The following information was provided by the Utah Division of Waste Management and Radiation Control (the Division) via email:
"Shipment 9075-01-0074 arrived at EnergySolutions' Clive disposal facility on May 19, 2025. As Division inspectors were performing incoming waste shipment inspections, [Division] staff surveyed and observed a trailer that exhibited a dose rate of 10.5 mrem/hour at 2 meters from the outer plane of the conveyance. Upon this discovery, the [Division] inspector informed EnergySolutions' shipping and receiving staff of the discrepancy, [who] indicated that they were already aware of said discrepancy.
"The transport vehicle is a curtain-side, flatbed trailer."
Additional license number UT 2300478.
Utah event report ID: UT 25001
Agreement State
Event Number: 57722
Rep Org: SC Dept of Health & Env Control
Licensee: F and ME Consulting, Inc.
Region: 1
City: Orangeburg State: SC
County:
License #: 293
Agreement: Y
Docket:
NRC Notified By: Jacob Price
HQ OPS Officer: Ernest West
Licensee: F and ME Consulting, Inc.
Region: 1
City: Orangeburg State: SC
County:
License #: 293
Agreement: Y
Docket:
NRC Notified By: Jacob Price
HQ OPS Officer: Ernest West
Notification Date: 05/20/2025
Notification Time: 09:58 [ET]
Event Date: 05/19/2025
Event Time: 15:46 [EDT]
Last Update Date: 06/18/2025
Notification Time: 09:58 [ET]
Event Date: 05/19/2025
Event Time: 15:46 [EDT]
Last Update Date: 06/18/2025
Emergency Class: Non Emergency
10 CFR Section:
Agreement State
10 CFR Section:
Agreement State
Person (Organization):
Lilliendahl, Jon (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
Lilliendahl, Jon (R1DO)
NMSS_EVENTS_NOTIFICATION (EMAIL)
EN Revision Imported Date: 6/20/2025
EN Revision Text: AGREEMENT STATE REPORT - DAMAGED PORTABLE GAUGE
The following information was provided by the South Carolina Department of Environmental Services (Department) via phone and email:
"The licensee informed the Department via phone on May 19, 2025, at approximately 1546 EDT, that one of their authorized users backed over a Humboldt Model 5001 EZ portable gauging device (Serial No. 5732), containing 11 millicuries of Cs-137 and 44 millicuries of Am-241:Be. The licensee reported that no immediate health and safety concerns had been identified.
"The on-call duty officer was dispatched to the construction site to investigate the event. The Humboldt Model 5001 EZ portable gauging device was crushed on one side of the device and the securing rod (depth rod) was transversely broken off. The source rod was intact, remained in the shielded position, and did not appear to be visibly damaged. Dose rate surveys at the surface of the gauge and at 1 meter indicated no elevated exposure. The Department performed swipe tests of the affected areas in addition to ambient dose rate surveys. All results were background. The licensee packaged the gauge within its transport case and a survey was performed to ensure compliance with Department of Transportation requirements (Transportation Index) prior to transporting it back to the licensee's facilities to await disposal.
"This event is still under investigation by the Department."
* * * UPDATE ON 6/18/2025 AT 1620 EDT FROM JACOB PRICE TO ERNEST WEST * * *
The following information was provided by the South Carolina Department of Environmental Services (Department) via email:
"The licensee submitted the 30-day written report on June 16, 2025. Details of the 30-day written report were consistent with the details obtained from the licensee during the on-site visit and interviews. A leak test record of the portable moisture density device (Humbolt 5001 EZ serial number 5732) dated May 27, 2025, indicated the leak test results of less than 0.005 microcuries. The portable moisture density device (Humbolt 5001 EZ serial number 5732) was transferred to the manufacturer for repairs on June 3, 2025. As a result of this event, the licensee has updated their emergency and operating procedures, and training. The licensee has committed to training all portable moisture density device authorized users to the revised procedures."
South Carolina Event Number: SC250005
Notified R1DO (Warnek) and NMSS Events Notification (Email)
EN Revision Text: AGREEMENT STATE REPORT - DAMAGED PORTABLE GAUGE
The following information was provided by the South Carolina Department of Environmental Services (Department) via phone and email:
"The licensee informed the Department via phone on May 19, 2025, at approximately 1546 EDT, that one of their authorized users backed over a Humboldt Model 5001 EZ portable gauging device (Serial No. 5732), containing 11 millicuries of Cs-137 and 44 millicuries of Am-241:Be. The licensee reported that no immediate health and safety concerns had been identified.
"The on-call duty officer was dispatched to the construction site to investigate the event. The Humboldt Model 5001 EZ portable gauging device was crushed on one side of the device and the securing rod (depth rod) was transversely broken off. The source rod was intact, remained in the shielded position, and did not appear to be visibly damaged. Dose rate surveys at the surface of the gauge and at 1 meter indicated no elevated exposure. The Department performed swipe tests of the affected areas in addition to ambient dose rate surveys. All results were background. The licensee packaged the gauge within its transport case and a survey was performed to ensure compliance with Department of Transportation requirements (Transportation Index) prior to transporting it back to the licensee's facilities to await disposal.
"This event is still under investigation by the Department."
* * * UPDATE ON 6/18/2025 AT 1620 EDT FROM JACOB PRICE TO ERNEST WEST * * *
The following information was provided by the South Carolina Department of Environmental Services (Department) via email:
"The licensee submitted the 30-day written report on June 16, 2025. Details of the 30-day written report were consistent with the details obtained from the licensee during the on-site visit and interviews. A leak test record of the portable moisture density device (Humbolt 5001 EZ serial number 5732) dated May 27, 2025, indicated the leak test results of less than 0.005 microcuries. The portable moisture density device (Humbolt 5001 EZ serial number 5732) was transferred to the manufacturer for repairs on June 3, 2025. As a result of this event, the licensee has updated their emergency and operating procedures, and training. The licensee has committed to training all portable moisture density device authorized users to the revised procedures."
South Carolina Event Number: SC250005
Notified R1DO (Warnek) and NMSS Events Notification (Email)
Power Reactor
Event Number: 57718
Facility: Quad Cities
Region: 3 State: IL
Unit: [1] [2] []
RX Type: [1] GE-3,[2] GE-3
NRC Notified By: Jason Cooper
HQ OPS Officer: Robert A. Thompson
Region: 3 State: IL
Unit: [1] [2] []
RX Type: [1] GE-3,[2] GE-3
NRC Notified By: Jason Cooper
HQ OPS Officer: Robert A. Thompson
Notification Date: 05/19/2025
Notification Time: 15:09 [ET]
Event Date: 05/19/2025
Event Time: 10:45 [CDT]
Last Update Date: 05/22/2025
Notification Time: 15:09 [ET]
Event Date: 05/19/2025
Event Time: 10:45 [CDT]
Last Update Date: 05/22/2025
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):
Szwarc, Dariusz (R3DO)
Szwarc, Dariusz (R3DO)
| Unit | SCRAM Code | RX Crit | Initial PWR | Initial RX Mode | Current PWR | Current RX Mode |
|---|---|---|---|---|---|---|
| 1 | M/R | Y | 100 | Power Operation | 0 | Hot Shutdown |
| 2 | N | Y | 100 | Power Operation | 80 | Power Operation |
EN Revision Imported Date: 5/23/2025
EN Revision Text: MANUAL REACTOR SCRAM DUE TO LOSS OF FEEDWATER
The following information was provided by the licensee via phone and email:
"At 1045 CDT on May 19, 2025, with Unit 1 at 100 percent power, the reactor was manually tripped on lowering reactor water level caused by a loss of electrical power to the condensate and feedwater pumps. The trip was not complex with all systems responding as expected post-trip. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B) and an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) for the group II isolation, group III isolation, and Unit I emergency diesel generator (EDG) automatic start.
"Operations responded using emergency operating procedures and stabilized the plant in hot shutdown. Decay heat is being removed through the automatic depressurization system and the residual heat removal system.
"Coincident with the transient on Unit 1, Unit 2 experienced a trip of a reactor feed pump resulting in a runback of the reactor recirculation pumps. Unit 2 is currently stable at 80 percent power.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector and the Illinois Emergency Management Agency were notified."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
On Unit 1, all control rods fully inserted on the scram and outboard main steam isolation valves closed on a loss of power.
The initial bus trip was caused by control power perturbations due to a ground on the associated battery system.
* * * UPDATE ON 5/20/2025 AT 1200 EDT FROM MATTHEW FRITCH TO SAMUEL COLVARD * * *
"Based on additional investigation, it has not been confirmed that the initial bus trip was caused by a ground on the associated battery system. The cause remains under investigation."
Notified R3DO (Szwarc)
* * * UPDATE ON 5/22/2025 AT 1532 EDT FROM CONNER BEALER TO TENISHA MEADOWS * * *
"The scram was initially reported as manual; however, further investigation determined that it was automatically initiated."
Notified R3DO (Szwarc)
EN Revision Text: MANUAL REACTOR SCRAM DUE TO LOSS OF FEEDWATER
The following information was provided by the licensee via phone and email:
"At 1045 CDT on May 19, 2025, with Unit 1 at 100 percent power, the reactor was manually tripped on lowering reactor water level caused by a loss of electrical power to the condensate and feedwater pumps. The trip was not complex with all systems responding as expected post-trip. Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CFR 50.72(b)(2)(iv)(B) and an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(iv)(A) for the group II isolation, group III isolation, and Unit I emergency diesel generator (EDG) automatic start.
"Operations responded using emergency operating procedures and stabilized the plant in hot shutdown. Decay heat is being removed through the automatic depressurization system and the residual heat removal system.
"Coincident with the transient on Unit 1, Unit 2 experienced a trip of a reactor feed pump resulting in a runback of the reactor recirculation pumps. Unit 2 is currently stable at 80 percent power.
"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector and the Illinois Emergency Management Agency were notified."
The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:
On Unit 1, all control rods fully inserted on the scram and outboard main steam isolation valves closed on a loss of power.
The initial bus trip was caused by control power perturbations due to a ground on the associated battery system.
* * * UPDATE ON 5/20/2025 AT 1200 EDT FROM MATTHEW FRITCH TO SAMUEL COLVARD * * *
"Based on additional investigation, it has not been confirmed that the initial bus trip was caused by a ground on the associated battery system. The cause remains under investigation."
Notified R3DO (Szwarc)
* * * UPDATE ON 5/22/2025 AT 1532 EDT FROM CONNER BEALER TO TENISHA MEADOWS * * *
"The scram was initially reported as manual; however, further investigation determined that it was automatically initiated."
Notified R3DO (Szwarc)