Uranium is only naturally formed by the r-process (rapid neutron capture) in supernovae and neutron star mergers. https://en.wikipedia.org/wiki/Uranium#Origin

Uranium is only naturally formed by the r-process (rapid neutron capture) in supernovae and neutron star mergers. https://en.wikipedia.org/wiki/Uranium#Origin https://en.wikipedia.org/wiki/Uranium#Origin