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| Start date | Reporting criterion | Title | Event description | System | LER | |
|---|---|---|---|---|---|---|
| ENS 55326 | 24 June 2021 22:00:00 | 10 CFR 30.50(a) | Unplanned Contamination to an Individual | The following synopsis was received via phone call from the licensee's Radiation Safety Officer (RSO): At 1800 EDT on June 24, 2021 at the licensee facility, an employee left the work site unaware that he was contaminated on his skin and his clothing. The only places the individual traveled to were his car and his home before being called back to work at 1924 EDT to investigate the contamination event. When the individual came back to the facility, contamination was found on his hand including Sr-82, Sr-85, Rb-83, and Rb-84. The activity was 600,000 counts or 0.18 micro curies. Dose calculations have not been performed, however, the RSO does not believe the dose will be near any federal limits. The work area has been decontaminated and the individual's car has been surveyed and no contamination was found. The licensee plans to survey the individual's home as well as contact the NRC Region 3 materials inspector. The licensee is reporting the event under both 30.50(a) and 30.50(b)(1) as a precaution as more data is being collected.
The following information was received via E-mail: On June 24, 2021, at approximately 1800 EDT, Curium-Noblesville RSO became aware of a radioactive spill in a restricted (production) area. The spill occurred behind the production hot cells. The affected area is designated as a triple shoe cover area and cordoned to limit access. The RSO directed a Radiation Safety Technician to respond to and initiate the investigation and data collection. The Radiation Safety Technician performed contamination surveys and found a maximum count rate of 800,000 cpm. The Radiation Safety Technician subsequently remediated the spill to 70,000 cpm (below the administrative level of 100,000 cpm) within minutes of completing the survey. The spill initiated when a Chemist tried to manually un-crimp a vial containing approximately 695 mCi of Sr-82 and 703 mCi of Sr-85. As the the Chemist tried to un-crimp the vial, the glass below the crimp broke leading to a few drops to fall on the concrete floor behind the hot cells. During the initial investigation surveys, the RSO discovered that the production batch record was contaminated. This prompted the RSO to find the Chemist to ensure he was free of contamination. The RSO discovered that the Chemist had already left the site. The RSO immediately contacted the Director of Health Physics for assistance. They made the decision to bring the Chemist onsite for a survey. The RSO discovered that the Chemist's work clothes presented spots reading approximately 600,000 cpm on contact with the pants and 200,000 with the shirt. The RSO also found contamination on the right hand reading approximately 34,000 cpm. Because the Chemist had left the site, the RSO surveyed the Chemist's car and did not identify contamination above background levels. The RSO communicated the findings to the Director of Health Physics and initiated the decontamination activities for the Chemist. Prior to decontaminating the Chemist's hand, the RSO obtained a gamma spectrum to identify the radioactive contaminants. He found a mixture of Sr-82, Sr-85, Rb-83 and Rb-84. The Director of Health Physics reviewed the notification requirements prescribed in Part 20 and Part 30 and escalated the event to Curium management and legal teams. Curium made the decision to proactively report the event to the NRC Operations Center under 10 CFR 30.50(a) given that the notification was required within 4 hours of discovery and Curium had not acquired enough data to verify if any regulatory limit was exceeded or not. After the notification, the RSO stopped the decontamination activities after no further contamination was being removed. The RSO measured a residual contamination of 4,200 cpm on the hand. He then followed the Chemist to his home and performed a contamination survey of the areas in which the Chemist indicated that he had been present after leaving the work site that day. The RSO found no contamination above background levels. The Director of Health Physics performed an initial dose estimate on June 25, 2021. The RSO used Rb-84 as the most restrictive nuclide that yielded the highest dose in the mixture. The estimates indicated that the Chemist received approximately 1,203 mrem to the maximally exposed shallow dose equivalent (extremity), 636 mrem shallow dose equivalent (whole body) and 13 mrem deep dose equivalent. The RSO performed 24-hour urinalysis and did not find the presence of the radionuclides. All license material was accounted for. Curium personnel discussed the incident with NRC Region-III on June 25, 2021. Curium is in the process of completing formal root cause analysis. Notified R3DO (Stone) and the NMSS Events Notification E-mail group.
The following retraction is a summary received from the licensee via phone: As part of an internal investigation, the licensee determined that neither the employee nor any member of the public received any exposure exceeding regulatory limits. The licensee will notify the NRC Region 3. Notified R3DO (Pelke) and NMSS Events Notification via email. | ||
| ENS 54959 | 20 October 2020 14:00:00 | 10 CFR 30.50(b)(4) | Thermal Event Resulting in Loss of Integrity of Licensed Container | At 1000 EDT on October 20, 2020, a thermal event occurred inside a hot cell at the Curium facility in Noblesville, Indiana. The thermal event did not result in a chemical or radioactive material release. Prior to the incident, technicians were processing materials containing strontium 82 and 85 (quantities are unknown at this time). The pressure created by the reaction caused the rear door of the hot cell to open approximately eight inches and was immediately shut by the technicians. There is no contamination outside of the hot cell and there were no injured or contaminated personnel. The vessel containing the strontium material was observed to be intact and the resultant fire was extinguished by the hot cell's suppression system. No offsite fire assistance was required. Personnel have not accessed the hot cell due to elevated dose rates. Dose rates outside of the hot cell are within the facility's normal limits and historical averages. | ||
| ENS 54711 | 13 May 2020 12:00:00 | 10 CFR 30.50(b)(4) | Fire Involving Loss of Integrity of Licensed Container | At approximately 0800 EST on May 13, 2020, a thermal reaction occurred inside a production hot cell during a rubidium dissolution process. The pressure created by the reaction caused the back door of the hot cell to open approximately six inches for a few seconds. Curium employees performing the dissolution process immediately activated the hot cell fire suppression system to put out the fire, closed the hot cell door and placed the production area in a secured state. The open hot cell door released airborne radioactive material to a localized area inside the controlled and posted production area. Six employees that were in the vicinity of the production hot cell presented contamination. Contamination was also found on the floor immediately around the production hot cell. Curium's RSO isolated the affected area and used the data collected from personal surveys to preliminarily estimate the potential dose to the six employees and the total activity released from the hot cell. The initial dose estimates indicated that the employee with the highest exposure potentially received approximately 6.5 mrem DDE and <1 mrem CEDE. Urinalysis was performed to confirm the internal exposure and intake. At the time of this report, the urinalysis results are still pending. Analysis of air samples taken in the immediate affected area indicated the presence of Sr-82, Sr-85, Rb-83, Rb-84, and Rb-86. After the performance of contamination surveys, decontamination of affected employees and analysis of samples, Curium employees decontaminated the affected area. After decontamination procedures were completed, the affected area was released for normal operations within the same business day without the need for imposing additional radiological controls or restrictions. Radiological surveys confirmed that there was no detectable release of radioactive material to uncontrolled areas adjacent to the hot cell production area. Curium performed a preliminary root cause analysis on May 13, 2020. After completing a preliminary assessment of the dose and release of radioactive materials, Curium reviewed the notification requirements prescribed in 10 CFR 20.2203, 20.2204 and 30.50 and made a determination that neither the immediate nor 24-hour notification requirements were warranted. Curium performed a formal root cause analysis on May 14, 2020. Despite a belief that notification was not required, Curium communicated the incident in good faith to Mr. Jason Draper (NRC Region III) on May 14, 2020 at 1100 EST. After further discussions with Mr. Draper throughout May 14, 2020 and further review of the incident and conditions, Curium personnel made a decision to self-report the incident to the NRC Operations Center as specified under 10 CFR 30.50(b)(4). Curium is in the process of finalizing the root cause analysis, finalizing the dose estimates, completing confirmatory actions. |