Oklo

Pictured above is Fossil Reactor 15, located in Oklo, Gabon.

Boing Boing: October 13, 2002 - October 19, 2002 Archives 2002

As I understand it, he was quite impressed by the discovery of a nuclear fission reaction that took place in an underground uranium deposit in Oklo, Gabon, Africa.

Kepler Discovers Planets-like Objects Hotter Than Stars | Universe Today 2010

The most significant case occurred almost 2 billion years ago at Oklo, in what is now Gabon in West Africa, where six spontaneous nuclear reactors operated within a rich vein of uranium ore.

Nuclear waste management 2009

Apart from its formation in today's nuclear reactors, plutonium was formed by the operation of the natural reactors in a uranium deposit at Oklo in west Africa some two billion years ago.

Plutonium 2009

The world's oldest known nuclear reactors operated at what is now Oklo in Gabon, West Africa.

Nuclear power reactor 2009

However, it must be noted that the Oklo reactions proceeded because groundwater was present as a moderator in the "enriched" and permeable uranium ore.

Nuclear waste management 2009

Modern pebble-bed reactors are not much dissimilar from the natural fission reactor that ran at Oklo for some 10-15,000 years, and we didn†™ t all end up with three eyes from that one.

Think Progress » When All Else Fails, Start Fear Mongering 2005

Anyway Oklo should be redone to take into account variation in nuclear physics parameters (not just alpha) but that is a mess because of nuclear physics being generally messy.

The Screwy Universe Sean 2006

A fossil nuclear reactor is believed to have been discovered at Oklo in Gabon, Africa.

Edenomics 101 - The Panda's Thumb 2006

Reed enlightens Bruce with: The Oklo reactor is an actual geological event.

Edenomics 101 - The Panda's Thumb 2006