ENS 45070
ENS Event | |
|---|---|
04:00 May 12, 2009 | |
| Title | External Contamination Found on Modified Sealed Source |
| Event Description | The following information was obtained from the licensee via facsimile:
One of the research projects at NIST involves research and testing of different types of bomb detection instruments. One of the experiments required that the source be removed from one of the instruments. Prior to January 2008, Researcher 1 spoke to the RSO for Smiths Detection in Canada. They discussed the possibility of removing the 15 mCi Ni-63 source from their instrument, an lonScan 400b, sealed source device number ND-0163-D-1014-G. The Smiths RSO approved this and sent schematics to assist with the project. Researcher 1 then started planning the project with NIST Health Physics review. It was decided that Health Physics would monitor this project to confirm that there was no unanticipated exposure or contamination resulting from the operation. On January 31, 2008, Researcher 1 began the process for source removal. Work was performed in a hood, in a controlled laboratory space, with a health physicist monitoring the operation. The process of source removal was based on the manufacturer schematics. These schematics were general and not a specific instruction for source removal. No information was available at the time that clearly defined the source encapsulation barrier. After a ceramic cap was removed, the side of the source holder was wiped and contamination was detected. It is believed that the wipe may have touched some of the nickel foil. Upon observing the way the source was placed in the ceramic in addition to the contamination detected, it was decided that it was not possible to safely modify the device in the intended manner. The ceramic head was reattached and reinserted into the box. External swipes were verified to be clean. It was decided to leave the source this way while it was determined if there was anything more they could do to meet the intended research results. It is believed that the sealed source containment was breached in the experiment thereby negating the manufacturer's sealed source certificate. In doing this, it became an unsealed source. The reassembly restored containment. The device was placed into secured storage. On May 12, 2009 wipes were taken of the external portion of the ceramic head and confirmed contamination of 72 nCi. A wipe was taken at the manufacturers recommended typical sealed source leak check location and was clean. The source box was collected for disposal. The hood, all items in the hood, and the floor were checked for potential contamination. They were verified to be clean. It is unclear whether this constitutes a reportable sealed source leakage situation with respect to 10CFR31.5c, since this occurred during an intended and controlled effort to modify the source configuration. The levels of unsealed source activity are within the limits prescribed in our license, SNM-362. |
| Where | |
|---|---|
| National Inst Of Standards & Tech Gaithersburg, Maryland (NRC Region 1) | |
| License number: | SNM-362 |
| Organization: | National Inst Of Standards & Tech |
| Reporting | |
| Other Unspec Reqmnt | |
| Time - Person (Reporting Time:+77.63 h3.235 days <br />0.462 weeks <br />0.106 months <br />) | |
| Opened: | Tim Mengers 09:38 May 15, 2009 |
| NRC Officer: | Howie Crouch |
| Last Updated: | May 15, 2009 |
| 45070 - NRC Website | |
National Inst Of Standards & Tech with Other Unspec Reqmnt | |
WEEKMONTHYEARENS 492572013-08-08T18:30:0008 August 2013 18:30:00
[Table view]Other Unspec Reqmnt Technical Specification Violation During Core Reload ENS 450702009-05-12T04:00:00012 May 2009 04:00:00 Other Unspec Reqmnt External Contamination Found on Modified Sealed Source 2013-08-08T18:30:00 | |