Module 101 Properties of Uranium
inhaled and a bsorbed into the bloodstr eam through
Provide a facility specific
example of uranium in gaseous
Another form of uranium that is an inhalation
hazard is the volatile UF6, becoming a gas above
56°C. However, most uranium daughters are not
volatile, an d so can accumula te in storage
cylinders. When the volatile UF 6 is extracted, the
nonvolatile daughters remain in the cylinder,
resulting in the buildup of residual radioactivity.
However, in the case of uranium-232 (232U),
uranium-235 (235U), and uranium-238 (238U), each
of these uranium isotopes has a radon daughter.
Radon is a gas at all but very low temperatures;
therefore, if the radon escapes, the subsequent
daughters can accumulate in closed or poorly
In some situations, pressure from volatilized UF 6
gas can build up in small volumes such as a sealed
container or a pipe run between two valves. Line
breaks and leaks will cause a release of th e UF6.
As the escaping UF6 gas cools, it becomes
particulate, which may have a suffocating effect on
any nearby workers.
Another reason for pressure buildup is alpha
particles emitted in radioactive decay eventually