Thirteen people at a University of Washington research facility were exposed to cesium-137 last week when a contractor attempted to remove a blood irradiator as part of a Department of Energy-funded program.
Personnel were removing a cesium irradiator manufactured by J. L. Shepherd and Associates from the premises on May 3 when the workers “nicked the cesium capsule” on the machine, Earl Fordham, deputy director of the Washington state Department of Health’s Office of Radiation Protection, told Nuclear Security & Deterrence Monitor on Tuesday.
The accident spilled an as-yet unknown quantity of finely powdered cesium chloride out of the irradiator, spreading traces of the gamma-emitting isotope throughout all seven floors of a research building near the university’s Harborview Medical Center, Fordham said.
Ten of the 13 people contaminated went to a hospital for treatment, according to a press release from the Department of Health. They were decontaminated and later released, the state agency said.
“No contamination was released outside of the area and there is no risk to the public,” the release says.
The department suspects the cesium spread through the building via its ventilation system, Fordham said.
“When they get up and actually survey the roof, we’ll be looking for it,” Fordham said Tuesday. “I haven’t heard any numbers up there yet.”
Personnel were removing the cesium blood irradiator as part of the Cesium Irradiator Replacement Project funded by the Department of Energy’s National Nuclear Security Administration (NNSA). The NNSA’s Office of Radiological Security manages the program, which aims to replace blood sterilization machines in hospitals that use potentially dangerous cesium-137 with machines that use X-rays.
Bad actors could use cesium in a radioactive dispersal device, sometimes called a dirty bomb.
A DOE Radiological Assistance Program team from Richland, Wash., responded to the accident at the University of Washington over the weekend and remained on-site Tuesday, the Health Department said. Such DOE teams help detect and assess radioactive isotopes at accident sites, and advise local authorities about containing those materials.
International Isotopes, which was also on site, according to the Washington state spokesperson, did not immediately respond to a request for comment. The Idaho Falls, Idaho, company provides radiological source recovery for the Energy Department, including irradiation devices.
