Understanding Nuclear Reactor Mechanics and the ancient history of the Oklo Natural Reactor provides a staggering look into how a Fission Chain Reaction can self-assemble within the Earth’s crust. By deconstructing the transition from the accidental geysers of West Africa to the futuristic Fission Fragment Reactor, we reveal the critical role of Delayed Neutrons and the structural hazards of Neutron Embrittlement. Two billion years ago, nature built 15 reactors in Gabon that utilized groundwater as a neutron moderator to slow neutrons down to a "putting speed," allowing for a self-sustaining cycle that pulsed like a heartbeat for hundreds of thousands of years. We contrast this natural feedback loop with the three million times energy density adv ...