ENS 57719
ENS Event | |
|---|---|
16:39 May 19, 2025 | |
| Title | Lost Sources |
| Event Description | 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
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 |
| Where | |
|---|---|
| Energy Northwest Environmental Services Laboratory Richland, Washington (NRC Region 4) | |
| License number: | WN-L0217-1 |
| Organization: | Wa Office Of Radiation Protection |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+0.15 h0.00625 days <br />8.928571e-4 weeks <br />2.0547e-4 months <br />) | |
| Opened: | Dane Blakinger 16:48 May 19, 2025 |
| NRC Officer: | Robert A. Thompson |
| Last Updated: | Jun 18, 2025 |
| 57719 - NRC Website | |
Energy Northwest Environmental Services Laboratory with Agreement State | |
WEEKMONTHYEARENS 577192025-05-19T16:39:00019 May 2025 16:39:00
[Table view]Agreement State Lost Sources 2025-05-19T16:39:00 | |