A worker at the Hanford Fire Station has tested positive for internal radioactive contamination at a very low level.
The exposure occurred after breathing equipment used at the nuclear reservation’s Plutonium Finishing Plant was sent to the station for storage, according to the Department of Energy.
Of 150 workers at the Hanford Fire Department, 104 have requested tests of their bodily fluid to determine if they also may have been exposed.
In December, contamination was found in cooling systems used within protective suits worn by Plutonium Finishing Plant workers that have high levels of radioactive contaminants.
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Eleven of the same kinds of cooling systems had been sent off Hanford for mechanical work, and they were tracked down to sites in Kennewick, Cincinnati and Pittsburgh.
Others were routinely stored by the Hanford Fire Department when they were not in use. Bioassay testing was offered to any worker who could have potentially come in contact with the equipment, called vortex coolers, according to the Department of Energy.
Preliminary results of bioassays for nine fire department employees have been completed, with eight negative and one positive result, said Erik Olds, chief of staff for the DOE Richland Operations Office.
The positive result was for one of two workers who worked most closely with the vortex coolers, which are serviced and repaired at the fire station. The other worker had a negative result.
A salesman took 11 vortex coolers from Hanford in the fall to troubleshoot a mechanical problem. Three of the coolers were in the trunk of his car and two of them were contaminated. He declined testing.
DOE says the worker with a preliminary positive result for internal contamination is not expected to face a significant health risk.
Additional tests are being done to confirm the positive result. If confirmed, a radiation dose to the body will be assigned to the worker within 90 days, according to DOE.
Six workers at the Plutonium Finishing Plant also have requested testing. Results for them and the remainder of the fire department workers who have requested testing should be available from an off-site laboratory in a matter of weeks.
Testing also was offered to a salesman for Mine Safety Appliances who took the 11 vortex coolers from Hanford in the fall to troubleshoot a mechanical problem. Three of the coolers were still in the trunk of his car and two of them were found to have contamination.
He declined testing. Workers a the Ohio and Pennsylvania facilities where other vortex coolers had been shipped also declined testing.
The Washington State Department of Health said the contamination found on the coolers in the salesman’s trunk was at very low levels and was fixed, rather than “smearable.”
As a precaution, surveys were done of the salesman’s car, his house, his storage unit and the out-of-state facilities without finding any contamination that had spread. No other contaminated equipment was found offsite.
110 workers request testing — 8 negative results, 1 positive, 101 pending
Workers at the Plutonium Finishing Plant use protective suits with supplied air breathing systems that are new to Hanford for some of the high-hazard work there. The puffy suits are filled with air to create higher pressure within the suit than outside it, helping to protect workers from airborne contamination.
The vortex coolers, each about the size of a shoebox, are worn inside the suits to cool the air within the suit, but not the air that workers breathe.
On Dec. 10, radioactive contamination was found on the elbow of a worker after a suit had been removed. As the worker’s equipment was examined, contamination was found on the outside and inside of the worker’s vortex cooler. All vortex coolers then were inspected.
Work was stopped on the three high-hazard projects at the Plutonium Finishing Plant, which is being prepared for demolition. Projects include cutting up the last large contaminated glove box, work inside the Americium Facility and work inside the Plutonium Reclamation Facility canyon.
Crews have since re-entered the Plutonium Reclamation Facility canyon to cap the floor with grout. The cap will provide shielding from radiological contamination and a level surface for workers when they begin decontaminating the canyon walls.
The other two high-hazard projects require wearing the air-filled suits. Contractor CH2M Hill Plateau Remediation Co. has decided to do just one project at a time that requires the suits, and work has resumed on the glove box rather than the Americium Facility.
CH2M Hill is sending a team of corporate safety and radiological control experts to do an on-site assessment and review of practices.
Plutonium Finishing Plant demolition still is planned to begin in the spring and to be completed by the end of 2016, Olds said.
DOE continues to work with CH2M Hill to take actions to prevent a recurrence, he said.
CH2M Hill radiological control personnel are making sure that vortex coolers are free of contamination before they are sent from the facility for storage or repair. The contractor also is reviewing its practices for releasing the coolers and related equipment, such as regulators and air bottles, from the facility.
Additional safety and industrial hygiene personnel, including managers, have been assigned to support the Plutonium Finishing Plant.
CH2M Hill also is sending a team of corporate safety and radiological control experts to do an on site assessment and review of practices. An in depth investigation into the cause of the incident is continuing, Olds said.