Event Notification Report for March 25, 2024

AGREEMENT STATE REPORT - STUCK SOURCE

The following information was received from the Massachusetts Radiation Control Program (the Agency) via email:

"On 3/14/2024 at 1225 EDT, a MDS Nordion, Inc. GammaMed Plus iX high dose rate (HDR) remote afterloader device malfunctioned, leaving the source in an unshielded position. Since the quality assurance/quality control (QA/QC) checks are performed in a shielded room, no individuals received any excess dose due to this device failure.

"On the same day at 1630 EDT, individuals from a device manufacturer, Varian Medical Systems, Inc. (NRC License # 45-30957-01) came to the site and returned the device to a shielded position. One field agent received a dose of 0.025 mSv [2.5 mrem] during this operation.

"On 3/15/2024, Varian personnel performed work to repair the device. This repair work is ongoing at the time of this report.

"The Agency will follow up with UMass Healthcare Radiation Safety Officer (RSO) to determine event cause and corrective actions.

"The Agency considers this event open. The Agency will follow up with a special inspection of the licensee."

Device Information:
MDS Nordion, Inc. GammaMed Plus iX HDR remote afterloader (sealed source and device registry number: CA-1080-D-103-S)

Source Information:
MDS Nordion Inc. model GM 232, Ir-192, 4.4 Ci (sealed source and device registry number: CA-1080-S-104-S)

NMED Number: TBD

AGREEMENT STATE REPORT - LOST GAUGE

The following report was received by the California Department of Public Health:

"On March 15, 2024, the RSO [radiation safety officer] for RMA Group notified the California's Department of Public Health, Radiologic Health Branch of the loss of a Troxler moisture density gauge. The serial number is 30520, and it contains 8 mCi of Cs-137 and 40 mCi of Am-241/Be. The Troxler gauge was inside a locked type A transit case and the trigger lock was used to secure the Cs-137 rod into the safe position. The gauge was reported as lost from the back of the operator's open bed pick-up truck. The Radiologic Health Branch is conducting an investigation of the event."

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 REPORT - STOLEN MOISTURE DENSITY GAUGE

The following information was provided by Alabama Radiation Control via email:

"The licensee's radiation safety officer (RSO) called Alabama Radiation Control at approximately 1549 CDT on Monday, 3/18/2024, to advise that one of their technicians had lost [reported stolen] a portable moisture density gauge at approximately 1445, around Bon Secour, AL.

"The RSO stated that the technician realized that the gauge was missing upon arrival at the licensee's location. The licensee received information that a member of the public (driving a gray F-150) stopped and retrieved the gauge.

"The licensee will notify local law enforcement, pawn shops, and advise local media about this matter. The licensee stated that a reward will be offered for the gauge's return. The RSO indicated that the source rod and transportation box were both locked.

"The gauge's (CPN MC-3) serial number is M39058845 with 10 millicuries of cesium-137 assayed March 1,1989, and 50 millicuries of americium-241/Beryllium assayed April 2, 1989."

The following additional information was obtained from the licensee in accordance with Headquarters Operations Officers Report Guidance:

Alabama Radiation Control verified that the gauge was stolen from an unsecured truck bed. Also, they indicated that they will follow-up to verify that local law enforcement, pawn shops, and local media were notified.

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

HIGH PRESSURE COOLANT INJECTION (HPCI) INOPERABLE

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

"At 0548 CDT on March 13, 2024, during a planned [high pressure coolant injection] HPCI maintenance window, a condition was identified not associated with the planned maintenance which caused HPCI to be inoperable. Specifically, the HPCI auxiliary oil pump start stop pressure switch could not be adjusted into calibration. Further investigation found that the pressure switch was not mounted as designed.

"Since HPCI is a single train system, this is a condition that could have prevented the fulfillment of a safety function; therefore, this condition is being reported as an eight-hour, non-emergency notification per 10 CFR 50.72(b)(3)(v)(D). The condition was corrected prior to HPCI being declared operable on March 15, 2024.

"The reason for the delay in the event notification beyond 8 hours from the event time was due to not recognizing the need to report the condition while in a planned HPCI maintenance window.

"The NRC Senior Resident Inspector has been notified."

NOTIFICATION OF UNUSUAL EVENT DUE TO FIRE IN THE PROTECTED AREA

The following information was provided by the licensee:

A Notification of Unusual Event, HU4.1 was declared based a fire in the protected area requiring off site assistance to extinguish. The fire was in the main transformer yard. The fire was detected at 2328 CDT on March 21, 2024, and the fire was declared out at 0009 CDT on at March 22, 2024. An automatic reactor trip was initiated due to a loss of offsite power to the "B" train and a failure to automatically transfer from unit auxiliary transformer "B" to startup transformer "B."

The licensee notified State and local authorities and the NRC Resident Inspector.

The NRC remained in Normal.

Notified DHS SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

* * * UPDATE AT 0345 EDT ON 03/22/24 FROM LARRY GONSALES TO BILL GOTT * * *

The licensee terminated the Notification of Unusual Event at 0221 CDT on 3/22/24.

The licensee notified the NRC Resident Inspector.

Notified R4DO (Gepford), IR-MOC (Grant), NRR-EO (Felts), DHS-SWO, FEMA Operations Center, CISA Central, FEMA NWC (email), CWMD Watch Desk (email), DHS NRCC THD Desk (email), and DHS Nuclear SSA (email).

* * * UPDATE AT 0420EDT ON 03/22/24 FROM JOHN LEWIS TO BILL GOTT * * *

RPS ACTUATION

The following information was provided by the licensee via email:

"On March 21, 2024, at 2328 CDT, Waterford 3 Steam Electric Station, Unit 3 was operating at 98 percent power when an automatic reactor trip was initiated due to a loss of offsite power to the 'B' train and a failure to automatically transfer from unit auxiliary transformer 'B' to startup transformer 'B.'

"Emergency feedwater actuation signal 2 (EFAS), safety injection actuation signal (ECCS), containment isolation actuation signal and emergency diesel generators automatically actuated. The unit is currently stable in Mode 3. All control rods fully inserted and all other plant equipment functioned as expected. Forced circulation remains with one reactor coolant pump per loop running. Decay heat removal is via the main condenser. 'A' train safety bus is being supplied by off-site power, and 'B' train safety bus is being supplied by emergency diesel generator 'B.'

"Following the loss of offsite power to the 'B' train, it was reported that main transformer 'B' and startup transformer 'B' were both on fire. The Emergency Director declared an Unusual Event at time 2337 CDT. The fire was reported extinguished at 0009 CDT on March 22, 2024, and the Unusual Event was terminated at 0221 CDT on March 22, 2024. Offsite assistance was requested. The local fire department responded to the site but the fire was extinguished by the on-shift fire brigade. NRC Region IV management was contacted regarding the emergency plan entry at 0030 CDT on March 22, 2024.

"This event is being reported as a 4-hour non-emergency notification in accordance with 10 CFR 50.72(b)(2)(iv)(B) as an actuation of the reactor protection system (RPS) when the reactor is critical and as an 8-hour non-emergency notification in accordance with 10 CFR 50.72(b)(3)(iv)(A) as valid actuation of the EFW system, ECCS, Containment Isolation and Emergency Diesel Generators.

"The NRC Resident Inspector has been notified."

Notified R4DO (Gepford)

AUTOMATIC TURBINE DRIVEN AUXILIARY FEEDWATER PUMP ACTUATION

The following information was provided by the licensee via email:

"At 2056 on 3/21/24, Callaway Plant was in Mode 1 at approximately 100 percent power when an automatic start of the turbine driven auxiliary feedwater pump occurred. The event occurred while restoring inverter NN12 from maintenance. NN12 is the normal in-service inverter for the group 2 120-VAC instrument bus (NN02). The actuation occurred while swapping from the swing inverter (NN18) to the normal in-service inverter (NN12).

"All safety systems responded as expected. At 2334, the turbine driven auxiliary feedwater pump was secured.

"The plant is being maintained in a stable condition in Mode 1.

"The NRC Resident Inspector was notified"

The licensee is investigating the cause of the automatic start.

REACTOR TRIP DUE TO MAIN TURBINE TRIP

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

"At 0852 EDT on March 22, 2024, with Unit 2 at 48 percent reactor power, Unit 2 reactor automatically tripped due to a main turbine automatic trip from a high-high thrust bearing position trip signal.

"This notification is being made in accordance with 10 CFR 50.72(b)(2)(iv)(B), reactor protection system (RPS) actuation as a four hour report. This notification is also being made in accordance with 10 CFR 50.72(b)(3)(iv)(A) due to automatic auxiliary feedwater system actuation immediately following the turbine and reactor trip as an eight hour report.

"The DC Cook Resident NRC Inspector has been notified.

"Unit 2 is being supplied by offsite power. All control rods fully inserted. Both motor driven auxiliary feedwater pumps and the turbine driven auxiliary feedwater pump automatically started on the reactor trip. Decay heat is being removed via the steam dump system to the main condenser. Preliminary evaluation indicates plant systems functioned normally following the reactor trip. Unit 2 remains stable in Mode 3 while conducting the post trip review. No radioactive release is in progress as a result of this event."

AUTOMATIC REACTOR TRIP

The following information was provided by the licensee via email:

"At 0004 EDT on March 23, 2024, with the unit in Mode 1 at 23 percent power, the reactor automatically scrammed due to high reactor pressure vessel pressure when the turbine bypass valves unexpectedly closed while attempting to lower generator MW to 55 MWe to support shutdown for a refueling outage. The scram was not complex, with systems responding normally post-scram, with the exception of the pressure control system. The transient occurred while lowering on turbine speed/load demand which caused a rise in pressure and power until the reactor protection system setpoint for reactor pressure high was exceeded and resulted in an automatic reactor scram. The plant was preparing to shut down for a refueling outage when the trip occurred.

"Operations responded and stabilized the plant. Reactor water level is being maintained at normal level. Decay heat is being removed by the main steam system to the main condenser using manual operation of the turbine bypass valves. All control rods inserted into the core.

"Due to the reactor protection system actuation while critical, this event is being reported as a four-hour, non-emergency notification per 10 CPR 50.72(b)(2)(iv)(B). Additionally, received expected [primary containment] isolations for Level 3: Group 13 drywell sumps, Group 15 [traverse in-core probe] TlPs (which was already isolated) and Group 4 [residual heat removal - shutdown cooling] RHR-SDC (which was already isolated). The primary containment isolation event is being reported under 10 CFR 50.72(b)(3)(iv)(A). Also, due to the main turbine bypass valves unexpectedly closing, this is also being reported under 10 CFR 50.72(b)(3)(v)(D).

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