How is cobalt-60 made?

Answer 1

Cobalt-60, or Co-60 (and sometimes 60Co), is an unstable isotope of cobalt. It is radioactive. Co-60 is made by a process called activation. In activation, a cobalt (cobalt-59) shape (a "slug" or "pellet") is lowered into an operating nuclear reactor and exposed to the neutron flux. The cobalt-59 will absorb a neutron and become cobalt-60, and the sample (now called a source) is then withdrawn from the reactor and put into a heavily shielded casket for storage. Once our source is secured, it is assigned a special Nuclear Regulatory Commission tracking number. This source was licensed before it was made, and it will be continuously tracked throughout its long, long life. The source is used for any one of a number of things, and a link is provided to a question on that subject.

The Co-60 has a half life of 5.27 years, and as it decays to nickel-60, or Ni-60 (60Ni), it goes through a three-step decay process and is dangerously radioactive throughout the time it decays. Remember that the 5.27 year half life means that half the sample has decayed in 5.27 years. There is still a lot around, and half of the remaining half decays in another 5.27 years - still leaving a lot remaining. Depending on the size of the originally activated sample, it can take a long time for the level of radioactivity to go down to anything near a "low" level. It can take hundreds or thousands of years for the sample to decay to the point where it can be removed from storage in a heavily shielded container.

Answer 2

Cobalt-60 is typically produced by bombarding cobalt-59 with neutrons in a nuclear reactor. During this process, cobalt-59 absorbs a neutron and is converted into cobalt-60 through a series of nuclear reactions. This is a common method for producing radioactive isotopes for various applications, including industrial and medical uses.