At least two Idaho National Laboratory workers inhaled plutonium oxide Tuesday at a nuclear reactor that has been closed down since 1992.
A third employee may have gotten an internal dose of the slightly radioactive material. Sixteen employees were exposed to the plutonium at the Zero Power Physics Reactor, INL officials said in a telephone press conference Wednesday. The employees were decommissioning the reactor that was fueled by weapons-grade plutonium -- plutonium pure enough to build bombs.
They were packaging the fuel for transport to a DOE facility in Nevada, but the destination is classified, officials said. DOE officials told me in the 1980s when I toured the reactor that the weapons-grade plutonium was loaned to the U.S. by the British government.
The fuel, in stainless steel cladding, was allowed to come into contact with oxygen, creating the plutonium oxide that is toxic and easily inhaled. But the workers were unaware the very pure plutonium had degraded.
The “hazards were not thoroughly understood and controls were not properly in place,” said Phil Breidenbach, nuclear operations director of the Materials and Fuel Complex that used to be the Experimental Breeder Reactor II complex.
Plutonium oxide exposure externally is not a threat because it emits only alpha radiation. But itcan lodge in the lung as a particle.
It can be coughed out but the plutonium can get into the bloodstream. Plutonium that reaches body organs generally stays in the body for decades and continues to expose the surrounding tissue to radiation, which increases the risk of cancer.