|Principle of technetium-99 transmutation|
A long-lived fission product – its half-life is 210,000 years – technetium-99 is one of the elements for which transmutation could be envisaged. Capturing a neutron accelerates its return to stability, causing a much more rapid beta disintegration. Once it has captured a neutron, technetium-99 becomes technetium-100, a much more unstable nucleus. This turns into a stable nucleus of ruthenium-100 after a few seconds. Once again, sufficient numbers of neutrons have to be captured to benefit from this phenomenon.