There is no significant fission reactor in the Earth's core. If there were, we could detect the antineutrinos from fission product decay. I'm not sure where t

There is no significant fission reactor in the Earth's core. If there were, we could detect the antineutrinos from fission product decay. I'm not sure where this idea came from. Perhaps from the mistaken notion that uranium, being heavy, sinks into the core? Uranium is actually highly enriched in the Earth's continental crust, by a factor of about 1000 vs. the planet as a whole.