Uranium is widespread across the planet in extremely low concentrations but seldom sufficiently concentrated to be economically recoverable. Uranium ore can be mined
by underground or open-cut methods, depending on its depth. The extracted ore is crushed and ground up, then treated with acid to dissolve the uranium, which is then
recovered from solution. Left over from this process is a slurry (tailings) that is collected in large tanks. Uranium may also be mined by in situ leaching (ISL), where it is dissolved from the ore-body and pumped to the surface for further processing. After drying the pulverised uranium ore is then made into "Yellow Cake", the raw material for both nuclear reactors and nuclear weapons.

Uranium – like all radioactive elements – undergoes a process of decay. Over long timespans, uranium releases energy and changes its form to produce other, distinct, elements in a continuous cascade. The U-238 isotope takes 4.5 billion years to decay by fifty percent – known as one “half-life” – which in turn produces different radioactive elements, creating a radioactive decay chain from uranium through to eventually reach a stable isotope of lead. Important decay products in the uranium cascade – known as “progeny” – include thorium, radium, radon gas, polonium and bismuth – all of these emit radioactive waves or particles (the release of energy during radioactive decay).