Oklo natural reactors

{
  "id": "MLC-T-CHM-008207",
  "term": "Oklo natural reactors",
  "field": "Chemistry",
  "definition": "A series of sites in Gabon where self-sustaining nuclear fission reactions occurred naturally approximately 1.7 billion years ago. These geological formations contained uranium ore with a sufficiently high concentration of the fissile isotope uranium-235 (around 3.7%) and groundwater that acted as a neutron moderator, allowing criticality to be reached. The study of the fission products and their migration provides unique data for validating models of long-term geological storage of radioactive waste.",
  "subject": "Chemistry and Human Health",
  "references": [
    "PAC, 2009, 81, 829. 'Glossary of terms used in ecotoxicology (IUPAC Recommendations 2009)' on page 922 (https://doi.org/10.1351/PAC-REC-08-07-09)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/oklo-natural-reactors/"
}