Uranium precipitates out of igneous hydrothermal waters when it encounters organic carbon. So it is probably concentrated in some oil deposits. Then some radiat

Uranium precipitates out of igneous hydrothermal waters when it encounters organic carbon. So it is probably concentrated in some oil deposits. Then some radiative isotopes of uranium will decay into radium, alpha particles (ionized helium) and other elements. Most of the worlds commercial helium is mined from natural gas, which may have fractions as much as 5%. This helium is thought to be from uranium decay emitting alpha particles and not primordial helium.