ENS 53532
ENS Event | |
|---|---|
04:00 Jul 26, 2018 | |
| Title | Agreement State Report - Unplanned Contamination Event |
| Event Description | The following information was received via E-mail:
During the process of shredding filters for cement solidification, the licensee had an unplanned contamination event. Loose surface contamination was spread throughout the building with an estimate of total activity being 2 milliCuries and the primary isotope being Cobalt-60. In addition to building surfaces, several personnel who were working in the area at the time were contaminated. It is unclear at this time the extent of the personnel contamination but inhalation and skin contamination are believed to have occurred. The licensee is currently decontaminating the area using protective clothing and respiratory protection, monitoring the individuals who were working in the area during the time of the event, and has sent a sample of the material to an independent lab for isotopic analysis. The licensee will be performing a root cause analysis and the state will perform a reactive inspection. The cause of the event is unknown at this time. PA Event Report ID No: PA180016
The following update was provided via E-mail: During the process for cement solidification of shredded filter materials the licensee's mixing unit auger became stuck. Technicians eventually, through the use of various manual and air tools, were able to remove the blockage and resume the solidification process. At this time the unit was run again with only a cement mixture with no filter media to create a cap in the disposal container. Upon completion of this procedure a crane operator entered the containment area to remove the filter media hopper from atop the unit. He had forgotten his hard hat and immediately left containment and the H-1 building to retrieve his hat. Upon entering the Personnel Contamination Monitor (PCM) he then set off the alarm. This was the first indication of contamination. The RSO was immediately contacted and all remaining personnel exited the building and were found to be contaminated. Immediately upon discovery of the incident, all doors to the contaminated building (the H-1 building) were locked, all operations equipment was placed in the off position, and the building was secured. Building access was then restricted. The plant manager stopped all work at the site and informed his chain of command. In the days following the event the licensee performed a detailed survey to assess the extent of contamination. The survey showed general distributed contamination of the horizontal surfaces within the building. The maximum contamination level identified with this survey was 800,000 dpm/100cm2. The primary isotope was Co-60 (-90%), with Mn-54 and Sb-125 as other contributors. Seven personnel exhibited general distributed contamination of varying amounts on their exterior clothing and/or shoes and had indication of inhalation of radioactive material. All showered in the onsite Decontamination Room and then were monitored with an extended count in the PCM and all were released with only gamma related upper torso activity. Nasal swabs from affected personnel were analyzed, however the license has yet to share these or any other personnel dose data. Daily extended PCM counts continue for available personnel who exhibit upper torso gamma activity. Four individuals continue to exhibit this activity. In addition, in-vivo and in-vitro bioassay measurements were initiated and are in progress to complete the internal dose assessment process. It is expected that the offsite laboratory bioassay measurement data will be available in 2-3 weeks and the internal dose assessment will then be completed. The H-1 Building Containment itself remains restricted. The H-1 Building Containment will remain restricted and the work activities related to the encapsulation of materials inside this containment have been suspended indefinitely. This status will continue until corrective actions have been implemented in order to prevent a reoccurrence of this incident. The licensee contends the initial root cause of the incident was inadequate procedure implementation and training regarding radiological containment inspection and certification. Corrective actions that are planned include: 1. H-1 Building Containment program overhaul. 2. Upgrade procedures to include routine containment inspections to be conducted and implement additional independent verification by Alaron's Radiation Safety staff. 3. Highlight Operational procedures to require signature requirement verifying proper ventilation alignment is functioning prior to commencement of work. 4. Alarming differential pressure gauges will be installed on the HEPA units to provide warning of both HEPA buildup and/or breakthrough. 5. The RSO will review the current application of constant air monitors against problematic conditions such as radon gas buildup to ensure alarm setpoints can adequately protect workers from excessive derived air concentrations in the work zone and retrain all staff. 6. The RSO will review and upgrade shield frisking stations to ensure proper contamination control in areas that have a high dose background. 7. Implement a recurring refresher training program in addition to the recertification training programs. 8. General Manager to conduct an all hands 1-day stand down to communicate priorities (i.e. Safety, Health and environmental stewardship are the top priorities; anyone can stop a job if they feel any of these are being compromised, etc.) The cause of the event is believed to be inadequate procedure implementation and training. RIDO (Lilliendahl) and NMSS were notified. |
| Where | |
|---|---|
| Alaron Nuclear Solutions Wampum, Pennsylvania (NRC Region 1) | |
| License number: | PA-0678 |
| Organization: | Pa Bureau Of Radiation Protection |
| Reporting | |
| Agreement State | |
| Time - Person (Reporting Time:+175.8 h7.325 days <br />1.046 weeks <br />0.241 months <br />) | |
| Opened: | John Chippo 11:48 Aug 2, 2018 |
| NRC Officer: | Brian Lin |
| Last Updated: | Aug 30, 2018 |
| 53532 - NRC Website | |
Alaron Nuclear Solutions with Agreement State | |
WEEKMONTHYEARENS 535322018-07-26T04:00:00026 July 2018 04:00:00
[Table view]Agreement State Agreement State Report - Unplanned Contamination Event 2018-07-26T04:00:00 | |