What is the difference between cobalt and uranium?
Uranium-235 and cobalt-60 are both radioactive, insoluble metals. Naturally occurring radioactive uranium-235 is extracted from the uranium ore mined for use by the nuclear power industry. This process leaves behind ‘depleted uranium’ (depleted of uranium-235) that is still radioactive but at a lower level than in nature. The density of depleted-uranium is 1.7 times that of lead. Because of its extremely high density it is used to trim the balance of commercial aircraft and it makes a very effective shielding for containers used to transport radioactive material. The depleted uranium is encased in steel as part of the container design, and in this form it is a benign material that emits much less radiation than the mined ore. Cobalt-60 is a man-made radioisotope that is made for two principal applications in medical sterilization and cancer therapy. It is made by putting natural cobalt metal (cobalt-59) in a nuclear reactor to convert it to radioactive cobalt-60. It takes 5ΒΌ years for
