Nuclear Power In the push for nuclear power, proponents of fast neutron reactors have portrayed this design as a new, promising technology that could resolve the question of managing long-lived radioactive waste. But the idea of fast neutron reactors is not a new one. Ever since the first experimental fast neutron reactor generated electricity in 1951, 1 governments around the world have made huge investments into their development, but the return has been minimal. After decades of research and experimentation, fast neutron reactors remain unsafe, uneconomical, and unable to address the problems of nuclear power. Fast neutron reactors are typically high temperature reactors fueled by a plutonium/uranium blend and cooled using an inert gas or liquid metal. They were first promoted as a way to extend uranium supplies, because as they operate, unusable uranium can be converted to fissile plutonium that can be used as fuel. It has since become clear that uranium is more abundant than originally thought. Now, fast reactors are being advocated as a waste solution that would reduce the radioactivity of spent fuel by converting long-lived plutonium and other radioactive heavy metals in the waste into shorter-lived radionuclides.