Uranium Is a Special, Important Material

Uranium just sitting around is constantly fisioning and constantly breaking up. And sometimes it's even in critical mass, but there's not a neutron moderator. You need that second piece to make the self-sustaining reaction happen. So some one predicted it. But have we an actual, like natural vision reactor on earth? Yes,. Actually, somebody has figured out that billions of years ago, deposits in the earth, in gabon in the african continent, did experience a nuclear self reaction.