Thorium is the answer
If it weren't for the radioactive decay of the unstable elements at the core of the Earth, life as we know it would not be possible. Thorium is one of the two radioactive elements found in abundance at the Earth's surface that can be refined into fuel to power a reactor for electric generation. Thorium is four times more abundant on Earth than Uranium.
Thorium reactors can also recycle nuclear 'waste' from conventional Uranium reactors leaving almost no waste to deal with. The reactor designs can not only recycle waste, they can breed additional fuels that can be 'burned' in the reactors themselves. These reactor designs are not reliant on high pressure steam or hot water to spin turbines that generate electricity. The level of radioactivity is much lower and the reactor designs developed by Oak Ridge National Laboratory in Tennessee have an automatic shutdown mechanism built-in if the reactor becomes too hot.
But the fact that its 'nuclear' scares people. Plutonium and U-238 are not produced as a by-product by a Thorium reactor so there is no potential for weapons grade Pu or U being produced. This is why the U.S. Government abandoned this design in the 1960's. They needed a reliable source for the production of Pu and U-238 in weapons grade refinement to power the nuclear weapons programs.