Event Notification Report for December 05, 2023

AGREEMENT STATE REPORT - FOUND GAUGES

The following information was provided by the Texas Department of State Health Services (the Department) via email:

"A Houston police officer was driving by a scrap yard on October 16, 2023, when his [personal radiation detector] PRD alarmed. He contacted his office, and another officer with radiation detection equipment went to the location and determined the radionuclide to be cesium-137. This officer contacted the Department, and on October 17, 2023, a Department investigator went to the location and located a box in a remote section of the scrap yard. The 4 foot by 4 foot by 4 foot box had several devices that appeared to be nuclear gauges in it. A service provider was contacted by the Department and put in contact with the property owner. The service provider responded to the location to remove the gauges and determine the source of radiation. Access to the area was restricted and controlled by the property owner. It does not appear that any individual would have exceeded an exposure limit. The service provider was able to determine that there was one source in the box. The source was placed in the back of a trash truck and shielded with all of the empty source holders stacked around it. The source holders all had the radioactive materials information removed.

"On October 19, 2023, a second service provider went to the site to retrieve the source. While there, they found three more shields in another area of the facility that were suspected to have sources that were very well shielded. All four sources (shields) were taken to the service provider's facility. The service provider removed the 4 sources. The service provider reached out to other individuals in an attempt to identify the manufacturer. It was determined that the sources were made by 3M and sold to Ronan Engineering, who then sold them to a DuPont plant in Wilmington, NC in 1992. The North Carolina program was contacted, and they reported that license was terminated in April of 2014. The sources were sent to a facility in South Carolina. The South Carolina program was contacted, and they provided a document showing the sources had been transferred to a Texas licensee in Sugar Land, Texas. The Texas licensee closed its facility and shipped all the sources they had for disposal. The last shipment of sources with this activity level was shipped from that facility in March of 2019. The contractor used to dispose of the sources has been contacted and will attempt to determine how the sources could have ended up at the scrap yard."

The Department will provide updated information as it is received.

Texas Incident Number: 10058
Texas NMED Number: TX230055


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

SAFETY SYSTEM MALFUNCTION

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

"[The following is a report of] reactor safety system component malfunction under Missouri University of Science and Technology Reactor (MSTR) Technical Specification (TS) 6.7.2.c)iii)

"At 1124 [CST], on December 1, 2023, with the MSTR at 180 kW, a `150 Percent Full Power' scram signal was received from one safety amplifier, and the reactor scrammed automatically. Based upon other nuclear instrumentation, at no point was reactor power at, above, or near the MSTR 300-kW Limiting Safety System Setting (LSSS), nor was any transient underway that could have yielded such a situation. Power was within the 2 percent automatic control setpoint window of 180 kW, and power dropped rapidly as expected following a scram. At the time of the event, the console operator observed that the affected safety amplifier went blank, and following an approximate 0.5 second delay, returned to a normal status tracking the decay power with a scram indicator illuminated.

"At no point was the health and safety of the public or MSTR in doubt. Due to ongoing reviews and replacement component sourcing, the MSTR has not operated since the event.

"Per MSTR TS 6.7.2.c)iii), `[the license shall make a report for] a reactor safety system component malfunction that renders or could render the reactor safety system incapable of performing its intended safety function unless the malfunction or condition is discovered during maintenance tests or periods of reactor shutdowns.' Following a thorough review of the scram logic and documented failure modes and effects analysis (FMEA) provided in the system's `Operation and Maintenance Manual' (Imaging & Sensing Technology Report 021-2103, Rev. 00), in the MSTR's opinion, the safety system malfunctioned but was able to complete its safety function. The event is being reported pending further review by facility staff and discussions with Nuclear Regulatory Commission facility project management.

"This report is being made under the provisions of MSTR Technical Specification 6.7.2, requiring a report by telephone to the NRC Headquarters Operations Center no later than the following working day. Under the provisions of MSTR Technical Specification 6.7.2, a written follow-up report will be submitted to the Commission within 14 days. Additional replacement parts will need to be secured and repairs performed to restore operability."


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

This event has been entered into the licensee's corrective action program.