XPS and XRD studies of samples from the natural fission reactors in the Oklo uranium deposits
- Whiteshell Research Labs., Manitoba (Canada)
Mineral samples from the natural fission reactors 10 and 13 in the Oklo uranium deposits were studied using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) to gain information about the long-term behaviour of UO{sub 2} fuel in a geological disposal vault. Two samples from reactor zone 10 (samples No. D81N-190292 and D73-88) and one sample from reactor zone 13 (sample No. SD37-S2/CD) were analysed. Low-resolution XPS spectra were recorded to determine the major elements present in the ore. High-resolution spectra were recorded to gain information about the chemical state of the elements present in the mineral samples. The samples show low values for the U{sup 6+}/U{sup 4+} ratio. The oxidation state of uranium in these samples is even lower than that in U{sub 4}O{sub 9}.The binding energies of the Pb 4f bands indicate most of the Pb is in the +2 oxidation state in these samples. The C ls band indicates the presence of organic carbon. XRD analysis shows that the main uranium-bearing phase is uraninite and lead is present mainly as galena. The significance of the results for nuclear fuel waste management is discussed.
- OSTI ID:
- 47906
- Report Number(s):
- CONF-931108-Vol.333; TRN: 95:011414
- Resource Relation:
- Conference: Fall meeting of the Materials Research Society (MRS), Boston, MA (United States), 29 Nov - 3 Dec 1993; Other Information: PBD: 1994; Related Information: Is Part Of Scientific basis for nuclear waste management XVII; Barkatt, A. [ed.] [Catholic Univ. of America, Washington, DC (United States)]; Van Konynenburg, R.A. [ed.] [Lawrence Livermore National Lab., CA (United States)]; PB: 964 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
The effects of water radiolysis on local redox conditions in the Oklo, Gabon, natural fission reactors 10 and 16
THE FATE OF THE EPSILON PHASE IN UO2 OF THE OKLO NATURAL FISSON REACTORS