Semantic search

The following information was received via facsimile from the Texas Department of State Health Services Radiation Branch: A contamination incident occurred at NSSI the morning of December 1, 2004. The incident involved the breaching of a sealed source as it was being removed from a device. The source involved was a 50 mCi Am-241Be source that was a part of a water salinity test device. The NSR-N source is inside an 8 inches long aluminum tube of about 1.5 inches diameter and is held in the center of the tube by two concentric tubes inserted from each end of the primary tube and pinned in place. The aluminum tube also contains a neutron detector to measure the backscatter neutrons when measuring the water in the device. In preparation for disposal of the source, the neutron tube is removed and discarded and the aluminum tube holding the source is removed from the water device. At the time of the incident, two persons were involved: The person operating the saw and the health physics monitor. A third person was in the machine shop area and about 4 feet away doing other work. The source rupture was noted immediately and health physics support was called to the area. Health physics personnel conducted initial surveys and removed the three personnel from the area. The involved personnel were surveyed out of the area, suited in PPE (personal protected equipment) and were escorted to the hot lab shower area. Nose wipes were collected for assay and each of the personnel showered to remove contamination and surveyed. (Water from this shower is captured in a tank for recovery and treatment.) After completing the release surveys, the involved personnel were released and sent home. The Texas Department of Health was contacted by the Headquarters Operations Center and added the following information. The source was apparently mispositioned in the tube and was cut by a band saw during the extraction process. Two of the individuals that were contaminated had nasal smears of 0.1 and 0.2 nanocuries. The third individual did not have any indication of contamination in the nasal smear. The contaminated individuals are scheduled to receive whole body counts.

• • • UPDATE FROM K. VERSER TO J. KNOKE AT 15:03 ON 3/25/05 ***

The following was emailed as an update to Event 41238:

Decontamination efforts are performed and coordinated by specialized team and monitored each week by DSHS staff. To date some 50 pallets of materials and equipment has been removed from the warehouse. These items were surveyed by agency staff with using alpha scintillation and taking random swipes. More than 90% of these items have been decontaminated with the remainder being shipped for disposal at appropriate facilities. An order impounding all sources of the model involved in the event have been impounded in place since December 10, 2004. All 50mCi Am/Be sources have been properly inventoried and ten of them were allowed to be sent to another licensee for removal and inventory. These were individually identified in the presence of agency staff. No contamination has been found outside of the warehouse and airborne activity inside is far below permissible levels and is being monitored with continuous air monitors (CAM)s. All that remains is a small, heavily contaminated area and that should be cleaned up in a couple of weeks. NSSI will survey and perform final decontamination of the building after which, Agency staff will perform a thorough survey to verify decontamination is adequate. Notified R4DO (Pick) and NMSS (Gillen)

• * * UPDATE FROM K. VERSER TO P. SNYDER AT 12:48 ON 5/5/05 * * *

The State provided the following information via email: Additional information received from Licensee, indicates two of the employees involved in the initial event, received Committed Effective Dose Equivalent exposures exceeding the annual limit. One employee, designated HP received 5.82 Rem and the other, designated Operator, received 10.7 Rem. In the letter transmitting this information, the licensee indicated it would be 3-4 weeks before the personnel monitoring supplier would have dose data from personnel monitors for the employees. Texas has requested additional information from the licensee regarding methodology used to determine CEDE for the employees. The licensee is also being required to submit the estimated Total Effective Dose Equivalent for each of the employees involved in the incident. Texas is continuing its investigation of this incident and will send a final report when the investigation is complete. Notified R4DO (Pruett) and NMSS (Hickey)