Oklo: historic and lessons learned

Two outstanding phenomena have taken place in earlier geological era where Gabon is now located: the presence of natural nuclear reactors and the appearance of a very elaborated form of life for its age. Calculations performed to establish the sustained fission history of Oklo site are presented first. Second, possible correlations between these two anomalies are discussed. Could the presence of ionizing radiation be the cause of genetic mutations? Today's isotopic measurements allow us to improve our understanding of the irradiation suffered by organic matter over all times. The first objective is therefore to quantify the possible effects of such ionizing radiation. A second objective naturally appears: the storage of radioactive waste. Calculations issued from the first objective provide access to nuclear reactor waste formations and Oklo is the unique natural analogue of a long-term storage laboratory for nuclear waste. Returning to our primary objective, it is interesting to extend our reflections to other situations of naturally radioactive environments such as very old geological formations or lagoon. (authors)