ENS Event | |
|---|---|
17:10 Dec 18, 2025 | |
| Title | Possible Overexposure |
| Event Description | The following is a summary of information provided by the licensee via phone and email:
On December 18, 2025, at 1010 MST, a three-person crew was manipulating the digital radiology panel while setting up for their next shot. When the assistant attempted to push the lock slide on the camera, he noticed it was already in the unlocked position and realized the source was exposed. The crew did not hear their rate alarms activate. A survey was not performed at the time, as the survey meter was located at the cranks during the incident. Based on initial estimates, the crew was approximately one foot from the source. Work was stopped immediately. The licensee performed preliminary dose calculations assuming the crew was on the shielded side of the collimator for approximately 5 minutes at 1 foot, resulting in an estimated dose of 1.7 rem. All three film badges are currently en route for rush processing. Camera Information: Model - D8039 Source Serial Number: 24751P Activity - 64 curies of Ir-192
The following is a summary of information provided by the licensee via email: The post event evaluation consists of a review of written statements, interviews with personnel involved, and examination of the equipment used. The review also recorded the film badge readings for the personnel involved. The evaluation revealed several potential contributing and causal factors. Corrective actions include retraining all crew members involved to refresh their knowledge on proper field operation set-up, safety, monitoring, and communication; and all radiography personnel will be briefed on lessons learned based on this event. Equipment Involved: Exposure Device: QSA Model 880 Delta, SN: D8039 Source Assembly: QSA Model A424-9, SN: 24751P, 64 curies Radiography Crew Involved: Radiographer #1, Pocket dosimeter dose recorded: off scale. Badge Reading 1,339 mrem. Radiographer #2, Pocket dosimeter dose recorded: 130 mrem. Badge Reading 136 mrem. Radiographer's assistant #2, Pocket dosimeter dose recorded: off scale. Badge Reading 1,068 mrem. Notified R4DO (Drake), NMSS Regional Coordinator (Allen), and NMSS Events Notification (email) |
| Where | |
|---|---|
| Mistras Group Inc Great Falls, Montana (NRC Region 4) | |
| License number: | 12-16559-02 |
| Organization: | Mistras Group Inc |
| Reporting | |
| 10 CFR 20.2202(a)(1) | |
| Time - Person (Reporting Time:+-2.97 h-0.124 days <br />-0.0177 weeks <br />-0.00407 months <br />) | |
| Opened: | Matt Kim 14:12 Dec 18, 2025 |
| NRC Officer: | Kerby Scales |
| Last Updated: | Jan 5, 2026 |
| 58094 - NRC Website | |
Mistras Group Inc with 10 CFR 20.2202(a)(1) | |
WEEKMONTHYEARENS 580942025-12-18T17:10:00018 December 2025 17:10:00
[Table view]10 CFR 20.2202(a)(1) Possible Overexposure 2025-12-18T17:10:00 | |