Thorium is readily available and can be turned into energy without generating transuranic wastes. Thorium's capacity as nuclear fuel was discovered during WW II, but ignored because it was unsuitable for making bombs.
A liquid-fluoride thorium reactor (LFTR) is the optimal approach for harvesting energy from Thorium, and has the potential to solve today's energy/climate crisis.
LFTR is a type of Thorium Molten Salt Reactor (Th-MSR). This video summarizes over 6 hours worth of thorium talks given by Kirk Sorensen and other thorium technologists.
Thorium is a naturally-occurring mineral that holds large amounts of releasable nuclear energy, similar to uranium. This nuclear energy can be released in a special nuclear reactor designed to use thorium.
Thorium is special because it is easier to extract this energy completely than uranium due to some of the chemical and nuclear properties of thorium.