Technetium is a highly unstable element, and so it is only found very rarely in minute quantities in the earth’s crust; these small amounts present in the earth’s crust are created as a byproduct from the spontaneous fission of uranium. Most of the technetium on the earth is produced, and isolated, in large quantities as fission waste in spent nuclear fuel rods; due to the radioactive properties of this element, the tons of technetium that are produced each year from nuclear reactors cannot yet be used for large scale commercial purposes.
One another reaction can be used to isolate technetium. This reaction uses the sulfide form of technetium, or the pertechnate form of technetium, and reacts it with hydrogen under heated conditions. During this isolation reaction, either Tc2S7, or NH4TcO4, is reacted with hydrogen and heated to 2012 °F. While this isolation reaction is effective, it is not normally used as so much technetium is produced from nuclear reactors.