Researchers report the enrichment of barium isotopes that are products of fissionogenic cesium, a significant component of nuclear reactor waste, within ruthenium metal and sulfide aggregates in a sample from the most active region of the 2-billion-year-old Oklo natural nuclear reactor in Gabon; the ratios of various isotopes suggests that the aggregates formed approximately 5 years after reactor shutdown and carry implications for long-term nuclear waste storage.
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Article #18-07267: "Discovery of fissionogenic Cs and Ba capture five years after Oklo reactor shutdown," by Evan E. Groopman, David Willingham, Alex Meshik, and Olga Pravdivtseva.
MEDIA CONTACT: Evan E. Groopman, United States Naval Research Laboratory, Washington, DC; tel: 202-767-8517, 410-258-6928; e-mail: evan.groopman@nrl.navy.mil
Proceedings of the National Academy of Sciences