ENS 44149
ENS Event | |
|---|---|
05:00 Apr 4, 2008 | |
| Title | Missing Depleted Uranium Source |
| Event Description | On April 4, 2008, a condition was identified at the Hematite Decommissioning Project that potentially involves missing licensed material in a quantity greater than 10 times the quantity specified in 10 CFR 20, Appendix C. Specifically, although it cannot yet be determined with certainty, it appears that a small depleted uranium pellet used as a detector source is missing. The radioactive source was one of several installed and used in Eberline, Model DA-1, gamma detectors to provide an indication of continuous operability. From the available documentation, it appears that the detectors were installed in 1993, well before Westinghouse acquired the facility in 2000.
If it is confirmed that the radioactive source indeed is missing and is of the type, quantity, and form of other similar detector sources present at the facility, the source is a depleted uranium pellet in a solid oxide form, with a total mass of approximately 5.5 grams. The total uranium mass of the source is approximately 4.85 grams. The uranium-235 (U-235) activity in the source is approximately 0.037 microcuries, which is a quantity greater than ten (10) times the 10 CFR 20, Appendix C, limit for U-235 of 0.001 microcuries. For reasons discussed further below, the circumstances under which the apparent loss of licensed material may have occurred cannot be determined with certainty. With the facility in a decommissioning status, it is possible that the source was separated from its detector during decommissioning activities performed since the site ceased fuel fabrication activities in 2001. Subsequently, the probable disposition of the source may have been its having been packaged and shipped either as Special Nuclear Material inventory removed from the site or as radioactive waste. Either situation is credible since significant decommissioning activities in the site Process Buildings has involved the removal of remaining Special Nuclear Material inventory and contaminated process equipment. As of the date of this report, immediate actions have included the following: (1) Similar detector sources from gamma detectors that no longer are needed/used have been removed and properly stored. (2) On April 7, 2008, a physical search and radiological surveys were conducted in an attempt to determine if the potentially missing radioactive source remains in the Process Building area. The source was not found. (3) An investigation is ongoing to confirm whether the licensed material is indeed missing. This investigation includes searching through Radiation Protection records for additional information regarding the source and any potential evidence of its disposition. It is noted that the ongoing investigation is challenged by: (1) the subject source and similar radioactive sources have not been formally tracked within an inventory and tracking system; (2) a change in facility ownership in 2000; and (3) site management and staff turnover since decommissioning started, such that individuals who may have had first hand knowledge of the cause and/or disposition of the subject radioactive source are no longer at the facility. The investigation into this event is continuing, and any further details will be provided in the written report that Westinghouse will submit within 30 days of this telephone report pursuant to 10 CFR 20.2201 (b). The licensee informed NRC Region 3 and the NRC Headquarters Program Manager. 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. This source is not amongst those sources or devices identified by the IAEA Code of Conduct for the Safety & Security of Radioactive Sources to be of concern from a radiological standpoint. Therefore is it being categorized as a less than Category 3 source |
| Where | |
|---|---|
| Westinghouse Hematite Hematite, Missouri (NRC Region 3) | |
| License number: | SNM-33 |
| Reporting | |
| 10 CFR 20.2201(a)(1)(ii) | |
| Time - Person (Reporting Time:+342.75 h14.281 days <br />2.04 weeks <br />0.469 months <br />) | |
| Opened: | Matthew Featherston 11:45 Apr 18, 2008 |
| NRC Officer: | Steve Sandin |
| Last Updated: | Apr 18, 2008 |
| 44149 - NRC Website | |
Westinghouse Hematite with 10 CFR 20.2201(a)(1)(ii) | |
WEEKMONTHYEARENS 441492008-04-04T05:00:0004 April 2008 05:00:00
[Table view]10 CFR 20.2201(a)(1)(ii) Missing Depleted Uranium Source 2008-04-04T05:00:00 | |