Event Notification Report for June 20, 2025

EN Revision Imported Date: 6/20/2025

EN Revision Text: SPECIFIED SYSTEM ACTUATION - AUTOMATIC START OF EMERGENCY DIESEL GENERATOR

The following is a summary of information that was provided by the licensee via phone and fax:

At 2108 EDT, on May 6, 2025, with Unit 3 in mode 5 at zero percent power, the plant received main steam line isolation, containment isolation phase 'A', and a safety injection signal which caused the emergency diesel generator to automatically start. The initiation signals were cause by inadvertent clearing of the pressurizer pressure low interlock during maintenance. There was no impact to decay heat removal, no injection into the core, and no loading of the emergency diesel generator. Operations staff responded and returned the plant to normal mode 5 operations.

There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified.

* * * RETRACTION FROM TED DI ANGELO TO BRIAN P. SMITH AT 1238 EDT ON 06/19/25 * * *

The following is a summary of information that was provided by the licensee via phone and email:

"Millstone Unit 3 is retracting NRC event notification (EN) 57694 regarding the inadvertent main steam line isolation, containment isolation phase 'A' and a safety injection (SI) signal which caused the emergency diesel generators to automatically start on May 6, 2025. This was reported as a valid actuation under 10 CFR 50.72(b)(3)(iv)(A). Subsequent evaluation has determined that the actuations were the result of an invalid signal caused by pinching a wire during a maintenance activity, which automatically unblocked the P-11 permissive.

"P-11 is a reactor protection permissive that automatically enables SI actuation when pressurizer pressure increases above 2000 psia. The permissive was unblocked as the result of the spiked pressurizer pressure indication caused by the pinched wires coincident with bistables associated with a separate pressurizer pressure channel tripped to support rescaling activities. With the plant shutdown, steam line pressures were low which met the condition to require a SI actuation with P-11 unblocked. This unblocking and resultant actuation was not a result of valid signals and was not an intentional manual actuation. The pinching of a wire causing a spike is not a valid signal and was not representative of actual plant conditions.

"Therefore, this condition is not reportable, and NRC EN 57694 is being retracted.

"The basis for this conclusion has been provided to the acting NRC Senior Resident Inspector."

Notified R1DO (Warnek)

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 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)

STUCK OPEN SHUTTER

The following is a summary of information that was provided by the licensee via phone:

On 6/10/2025 at approximately 1300 EDT, the licensee discovered that a Thermo Fisher density gauge containing 10 mCi of Cs-137 had a stuck open shutter while conducting routine checks on the gauge. Open is the normal position of the shutter. Surveys indicated the dose rate at 1 foot from the gauge is less than 1 mrem/hr. The gauge is on a pipe approximately 30 feet in the air, is not normally accessible, and poses no risk to personnel. The licensee has contacted a third party, Applied Health Physics, to assist them in decommissioning and disposing of the gauge.

EN Revision Imported Date: 6/20/2025

EN Revision Text: AGREEMENT STATE REPORT - FOUND SOURCE

The following is a summary of information provided by the Maryland Department of Environment via email:

On June 10, 2025, at 1600 EDT, the Maryland Department of the Environment's Radiological Health Program (MDE/RHP) was notified by the Maryland State Police that a cesium-137 source was found at the Shady Grove Solid Waste Transfer Facility. It was reported that a waste truck arrived at the waste transfer facility on Friday afternoon with the source inside. It was first misidentified as iodine-131 (as a bit of medical waste). It was then compacted and placed in a container express (CONEX) box. A second survey was performed and identified the source as cesium-137. The box was then held to prevent incineration. Wipe samples were taken on the surface of the container. There were no signs of leakage. The facility also used a high-purity germanium (HPGe) radiation detector to confirm the identity of the source. The highest measurement observed was 463 microroentgen per hour at about 1 foot from the estimated source position. The Department of Energy contact person was notified, and the source activity was estimated to be approximately 0.3 Ci. The facility plans to transfer the container to the Covanta Energy facility and attempt to locate the source and remove it from the container on June 11, 2025, at 1130.


* * * UPDATE ON 6/18/2025 AT 1729 EDT FROM KRISHNAKUMAR NANGEELIL TO ERNEST WEST * * *

The following information was provided by the Maryland Department of Environment via email:

"On June 11, 2025, representatives from the Maryland Department of the Environment (MDE), in coordination with FBI officials and the safety and environmental compliance manager at the Shady Grove Waste Transfer Facility, convened to execute the recovery plan for a missing sealed radioactive source. The team accompanied the transport of the suspect container to the Covanta Energy facility for inspection. Following a safety briefing, the container was unloaded in a slow, controlled manner. Maryland State Police were present to support the operation. Radiation surveys were conducted after each stage of unloading. The sealed source was located in the final portion of debris. A preliminary leak test confirmed only background radiation levels, indicating no removable contamination on the exterior of the source.

"The recovered item was identified as a benchmark Cs-137 sealed source, serial number BM06E-37-019-32. Originally manufactured with an activity of 8.325 MBq (0.225 mCi) on July 6, 2007, the current activity was calculated to be approximately 5.5 MBq (0.149 mCi), based on standard decay calculations. The source was secured in a sealed plastic bag, placed into a lead pig for shielding. All readings in other areas remained at background levels, and the container was released from further radiological control.

"On June 12, 2025, RadQual, the manufacturer, confirmed that the source had been shipped on September 28, 2007, to a licensed medical facility in Maryland. This information was provided by the commercial manager at RadQual.

"The source is currently being stored in a shielded, access-controlled area at the Shady Grove facility, pending final disposal through a licensed radioactive waste broker. All associated documentation will be completed and submitted to MDE in accordance with applicable regulatory requirements."

Maryland Event ID Number: 78276

Notified R1DO (Warnek) and NMSS Events Notification (email)

STUCK OPEN SHUTTER

The following is a summary of information provided by the licensee via phone and email:

On June 11, 2025, at 1104 EDT, the licensee discovered a stuck open shutter while performing daily checks on an x-ray gauge. The gauge is in an area that is taped off and poses no exposure risk to personnel or the public. The manufacturer is planning an on-site inspection and assessment of the gauge.

Gauge Model Number: Thermo Rm200EM
Gauge Serial Number: 543893
Source Activity: 1000 mCi (Americium-241)
Source Model Number: AM1.GXX
Source Serial Number: G44/004/09

* * * UPDATE ON 06/12/25 AT 1355 EDT FROM WAYNE LANGDON TO KERBY SCALES * * *

The following is a summary of information received from the licensee via phone and email:

The manufacturer (Thermo EGS Gauging) was on-site and inspected the unit. They identified that the magnetic coil position holding the shutter flag when it de-energized needed to be adjusted. Adjustments to its position were made, and the shutter is now working as designed.

Notified R3DO (Ziolkowski) and NMSS Events Notifications via email.

AGREEMENT STATE REPORT - MEDICAL EVENT

The following information was received from the Arizona Department of Health Services (the Department) via email:

"On June 11, 2025, the Department received notification from the licensee about a medical event occurring on June 10, 2025, involving a Nucletron Micro Selectron, Model 106.990, high dose rate (HDR) afterloader brachytherapy unit with a 10.4 Ci iridium-192 source. A patient was being treated for skin cancer on the right cheek and the prescription was for 4000 centigray (cGy) in 10 fractions of 400 cGy per fraction. The patient was treated on the left cheek for the first fraction. When the patient returned for the second treatment and the therapist was preparing them for treatment, the patient indicated that they thought the treatment should have been on the right cheek and not the left cheek. The authorized user immediately stopped the setup and verified that they had treated the wrong site. The Department has requested additional information and continues to investigate the event."

Arizona Incident Number: 25-011

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

AGREEMENT STATE REPORT - MEDICAL EVENT

The following information was received from the California Department of Public Health via email:

"University of California, Los Angeles (UCLA) Health reported that a patient being treated for liver cancer underwent a Y-90 brachytherapy microsphere treatment on June 9, 2025. The written directive by the authorized user called for 120 Gy each [to be administered] to both the middle section (a 3 GBq vial) and the right liver section (a 20 Gbq vial). Post therapy evaluations determined that the administered dose to the right section of the liver was 88.9 Gy (74.08 percent of the prescribed dose), which is an underdose of more than 20 percent. The administered dose to the middle section of the liver was 114.2 Gy (95.17 percent of the prescribed dose) and was in accordance with the written directive. UCLA Health is conducting an investigation and will submit a 15-day report to the California Radiation Health Branch.

California 5010 Number: 060925

A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.

EXTERNAL CONTAMINATION ON PACKAGING

The following is a summary of information provided by the licensee via phone:

Hawaii Pacific Health radiation safety officer received a call that Pali Momi Medical Center received a package with external technetium-99m loose surface contamination. The package contained indium-111 which was intact. The swipes on the outside of the package were 74,000 dpm/100 cm2 (decades per minute/100 centimeter squared). The package was placed in locked storage to prevent the spread of contamination. The common carrier was notified of the contaminated package.

AGREEMENT STATE REPORT - FOUND SOURCE

The following information was received from the Colorado Department of Public Health and Environment (CDPHE) via email:

"On June 3, 2025, at approximately 1450 MDT, Western Metals Recycling, a non-licensee, reported a radiation alarm to the CDPHE. The alarm occurred on a truck loaded with scrap steel. Western Metals facility staff performed surveys using a handheld instrument and observed a net radiation reading of approximately 15 microrem/hour in the area of the load behind the cab of the truck. CDPHE issued a DOT special permit to allow return of the shipment to the non-licensee Denver Scrap Metal Recycle Center. Denver Scrap Metal does not have a vehicle radiation monitoring system.

"CDPHE on-call staff responded to the Denver Scrap Metal facility at approximately 1645 on June 3, 2025. CDPHE staff performed radiation surveys of the truck driver, and no readings above background were noted. CDPHE staff performed radiation surveys of the accessible areas of the load, which had been unloaded onto the ground, focusing on the front of the truck. Radiation surveys eventually located and identified two radium-226 radio luminescent military personnel markers (each approximately 1.5 inches in diameter) as confirmed using a Flir Identifier survey instrument. Dose rate measurements of approximately 1.7 to 2.5 mrem/hour on contact with the Ra-226 markers were observed. Wipe surveys of the markers did not indicate the presence of gross contamination using the handheld instrument for analysis. The sources (markers) were placed in a small bag and then placed inside a metal container. The metal container was surrounded by lead found on site to provide interim shielding and reduce radiation. Facility staff were requested to label, secure, and isolate the Ra-226 sources in an area away from staff, pending final disposition. The facility has contacted a licensed waste broker/service provider to prepare and dispose of the sources.

"Based on Oak Ridge Associated Universities historical information (https://www.orau.org/health-physics-museum/), each marker may contain up to 7 microcuries of Ra-226.

"These items are considered to be generally licensed in accordance with Colorado Part 3, Section 3.6.8.1(4) / 10 CFR 31.12(a)(4). This event is reported, consistent with Section 8.3 (found source) of NRC Handbook SA-300 and Colorado Part 4, Section 4.51.1/10 CFR 20.2201(a)(ii)."

CO Event Number: CO250016

AGREEMENT STATE REPORT - DAMAGED GAUGE

The following information was provided by the North Dakota Department of Environmental Quality (the Department) via email:

"On June 12, 2025, at 1647 MDT, the Department received a notification from Minn-Dak Farmers Cooperative reporting an equipment issue identified on June 11, 2025. The issue involved a fixed nuclear gauge (Thermo MeasureTech model 7063, S/N: 1519A), containing a 500 millicurie (original activity) Cs-137 sealed source. The Department is waiting for specific sealed source information.

"The facility is transitioning into a scheduled plant maintenance and cleaning downtime period. As part of this downtime, the radiation safety officer (RSO) planned to replace the referenced fixed gauge. During this process, it was discovered that the fixed tab used to secure the shutter arm in the locked-out position had broken off. Although the shutter mechanism remains operational, the gauge can no longer be properly locked out due to the missing tab.

"There is no visible damage to the source holder's structure or housing. The gauge continues to function securely in its installed position and does not present an operational safety concern.

"The last shutter check was in March 2025, and there was no indication of damage to the fixed gauge [at that time].

"No overexposures occurred during this event.

"Currently, the RSO is in contact with the vendor for plans to remove and dispose of the gauge and replace it with a new gauge.

"This is reported per 10 CFR 30.50(b)(2)."

ND Event Number: ND250002

MANUAL REACTOR SCRAM

The following information was provided by the licensee via phone and email:

"On June 17, 2025, at 0426 CDT, Grand Gulf Nuclear Station (GGNS) was operating at 70 percent power when a manual scram was initiated due to degraded main condenser vacuum caused by the loss of the 'A' circulating water pump.

"All control rods fully inserted, there were no complications, and all plant systems responded as designed. Immediately after the scram, an expected reactor water Level 3 isolation signal was received. Reactor pressure is being maintained via the turbine bypass valves. Reactor level is being maintained via main feedwater. GGNS is currently in Mode 3. No radiological releases have occurred due to the event.

"The cause of the circulating water pump trip is under investigation.

"The manual reactor protection system actuation is being reported in accordance with 10 CFR 50.72(b)(2)(iv)(B). The expected reactor water Level 3 isolation signal is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A).

"The NRC Resident Inspector was notified."

UNPLANNED MAINTENANCE OF TECHNICAL SUPPORT CENTER SUPPLY FAN

The following information was provided by the licensee via phone and email:

"This is an eight-hour, non-emergency notification for a loss of emergency assessment capability. This event is reportable in accordance with 10 CFR 50.72(b)(3)(xiii) because the technical support center (TSC) supply fan belt failed [at approximately 1257 CDT on 6/17/2025] which affects the functionality of an emergency response facility.

"Corrective maintenance activities have been completed as of 6/17/25 at 1619 [CDT] to replace the TSC supply fan belt. The TSC supply fan has been re-started and this condition is no longer applicable.

"If an emergency would have been declared requiring TSC activation during this period, the TSC would have been staffed and activated using existing emergency planning procedures unless the TSC became uninhabitable due to ambient temperature, radiological, or other conditions. If relocation of the TSC were necessary, the Emergency Director would have relocated the TSC staff to an alternate location in accordance with applicable site procedures. The emergency response organization team was notified of the maintenance and the possible need to relocate during an emergency.

"There was no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified."

TURBINE CONTROL VALVE 3 MALFUNCTION

The following information was provided by the licensee via phone and email:

"On June 18, 2025, at 0553 CDT, River Bend Station (RBS) was operating at 100 percent reactor power when turbine control valve 3 (CV3) closed, causing both turbine bypass valves to open. Reactor power was lowered to approximately 95 percent and the bypass valves closed. At 0646 CDT, CV3 was observed opening and all other turbine control valves intermittently changing position causing the bypass valves to open again. Reactor power was lowered to 90 percent and the bypass valves closed. The bypass valves were open for approximately one minute for each of the two occurrences.

"With the bypass valves open, technical specification (TS) required instrumentation that utilize turbine first stage pressure were declared inoperable. The following instrumentation functions were declared inoperable: Reactor protection system - turbine stop valve closure and turbine control valve fast closure, trip oil pressure-low. Control rod block instrumentation - rod withdrawal limiter. End of cycle recirculation pump trip instrumentation - turbine stop valve closure and turbine control valve fast closure, trip oil pressure-low.

"Reactor power is currently at 90 percent. CV3 and the bypass valves are closed. All limiting condition of operation (LCO) conditions that were entered as a result of this event have been exited. All plant parameters are stable. Troubleshooting efforts to determine the cause of the CV3 malfunction are ongoing. The highest reactor pressure observed during this event was 1071 psig.

"This event is being reported under 10 CFR 50.72(b)(3)(v) as an event or condition that could have prevented fulfillment of a safety function due to inoperability of both divisions of TS required instrumentation functions.

"The NRC Resident Inspector has been notified."