caa a22 4500 465729215 CHVBK 20180323111736.0 cr unu---uuuuu 170327e19900901xx s 000 0 eng 10.1007/BF02039456 doi (NATIONALLICENCE)springer-10.1007/BF02039456 Kuroda P. Department of Chemistry, University of Nevada, 89154, Las Vegas, Nevada, (USA) aut The pre-Fermi natural reactor: A note on the periodic mode of operation [Elektronische Daten] [P. Kuroda] The isotopic compositions of xenon released from the Oklo reactor at temperatures below 1000°C are such that the abundances of131Xe,132Xe and134Xe relative to136Xe are markedly enhanced when compared to the relative fission yields from the thermal neutron-induced fission of235U. These anomalies can be attributed to the fact that131Xe,132Xe and134Xe have fairly long-lived precursors: 8.04-day131I, 78.2-hour132Te and 42-minute134Te, respectively. It is possible to determine the duration of the time when the reactor was turned off from the ratios of excess132Xe to excess134Xe in these anomalous xenon fractions released from the Oklo reactor. Calculations based on the available xenon isotope data that the time period during which the reactor was turned off was approximately 2 to 3 hours. Akadémiai Kiadó, 1990 Journal of Radioanalytical and Nuclear Chemistry Kluwer Academic Publishers 142/1(1990-09-01), 113-118 0236-5731 142:1<113 1990 142 10967 https://doi.org/10.1007/BF02039456 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02039456 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Kuroda P. Department of Chemistry, University of Nevada, 89154, Las Vegas, Nevada, (USA) aut NATIONALLICENCE 773 0- Journal of Radioanalytical and Nuclear Chemistry Kluwer Academic Publishers 142/1(1990-09-01), 113-118 0236-5731 142:1<113 1990 142 10967 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer