Gauthier-Lafaye

F. Gauthier-Lafay, P. Holliger, and P.-L. Blanc, Geochim. Cosmochim. Acta 60, 4831—4851 (1996). 

Nagy B, Gauthier-Lafaye F, Holliger P, Davis DW, Mossman DJ, Leventhal JS, Rigali MJ, Parnell J (1991) Nature 354 472... 

Gauthier-Lafaye, F., 2002, 2 billion year old natural analogs for nuclear waste disposal the natural nuclear fission reactors in Gabon (Africa). C. R. Physiquee 3 839-849. 

Bros, R., Turpin, L., Gauthier-Lafaye, F., Holliger, P., Stille, P. 1993. Occurrence of naturally enriched (super 235) U implications for plutonium behaviour in natural environments. Geochimica et Cosmochimica Acta, 57, 1351-1356. 

Gauthier-Lafaye, J. Perron, R. Methanol and Carbonylation Editions-Technip, Paris 1987, p. 152. 

Gauthier-Lafaye, J. Perron, R. Eur. Pat. Appl. 22 038, 1980. Pretzer, W.R. Habib, M.M. Proc. Symp. on Catalytic Conversion of Syngas and Alcohols, 17th Middle Atlantic Regional Mtg., Am. Chem. Soc., 1983. 

The Oklo natural reactors in Gabon are the best natural analogues for assessing the geological behaviour of fission products and actinides (see also Gauthier-Lafaye et al. 2004). Elements that were compatible with the U ore structure were retained, whereas elements that... 

Gauthier-Lafaye, F., Stille, P. Bros, R. 2004. The Gabon and Cigar Lake uranium ore deposits. In GlERE, R. Stillf., P. (eds). Energy, Waste, and the Environment a Geochemical Perspective. Geological Society, London, Special Publications, 236, 123-134. 

Stille, P., Gauthier-Lafaye, F. et al. 2003. REE mobility in groundwater proximate to the natural fission reactor at Bangombe (Gabon). Chemical Geology, 198, 289-304. 

Le Gal, X., Crovisier, J.-L., Gauthier-Lafaye, F., Honnorez, J. Grambow, B. 1999. Meteoric alteration of Icelandic volcanic glass long-term changes in the mechanism. Comptes Rendus de l Academie de Sciences, Paris - Serie Ila. Sciences de la Terre et des Planetes, 329, 175-181. 

The size of the reactors is quite variable. In length, the biggest reactor has dimensions of 12 x 18 m and has a thickness of 20 to 50 cm (Fig. la). The core of the reactors consists of a 5 to 20 cm thick layer of uraninite embedded in clays (illite and chlorite). Clays around the reactors result from the hydrothermal alteration of the host sandstone during the fission reactions. This alteration occurred at a temperature close to 400 °C in the core. Temperature decreased drastically toward the vicinity with a thermal gradient of 100 °C/m (Pourcelot Gauthier-Lafaye 1999). The uranium content of the core ranges between 40 and 60%. Accessory minerals are mainly sulphides (pyrite and galena), hematite and phosphates (mainly hydroxyapatite). 

It has been recognized that some fission and decay products had almost completely been retained, whereas others had been almost totally lost from the vicinity of the reactors (Gauthier-Lafaye et al. 1996) (Fig. 3). Elements that had been retained essentially within the core of the reactors are Pu, Th, REE, Zr, Ru, Rh, and Pd. These... 

Br acre, G., Salah, S. Gauthier-Lafaye, F. 2001. Weathering process at the natural fission reactor of Bangombe. Environmental Geology, 40, 403-408. 

Gauthier-Lafaye, F. 1986. Les gisements d uranium du Gabon ct les reacteurs d Oklo. Modele metallo-genique de gites a fortes teneurs du Proterozoique inferieur. Memoire Sciences Geologiques, 78, 206. 

Gauthier-Lafaye, F. Wf.ber, F. 1981. Les concentration uraniferes du Francevillien du Gabon ... 

Gauthier-Lafaye, F. Weber, F. 1989. The Fran-cevillian (Lower Proterozoic) uranium ore deposits of Gabon. Economic Geology, 84, 2267-2285. 

Hidaka, H., Holliger, P. Gauthier-Lafaye, F. 1999. Tc/Ru fractionation in the Oklo and Bangombe natural fission reactors (Gabon). Chemical Geology, 155, 323-333. 

Pourcelot, L. Gauthier-Lafaye, F. 1999. Hydrothermal and supergen clays of the Oklo natural reactors conditions of radionuclide release, migration and retention. Chemical Geology, 157, 155-174. 

Jensen, K. A., Janeczek, J., Ewing, R. C., Stille, P., Gauthier-Lafaye, F. Salah, S. 2000. Cran-dallites and coffinite retardation of nuclear fission products at the Bangombe nuclear fission reactor. Material Research Society Symposium Proceedings, 608, 525-532. 

Dr. Francois Gauthier-Lafaye, Centre de Geochimie de la Surface, ULP-EOST-CNRS, 1 rue Blessig, F-67084 Strasbourg, France. 

Gauthier-Lafaye O, Boucaud P, Julien FH, Prazeres R, Glotin F, Ortega JM, Thierry-Mieg V, Planel R, Leburton JP, Berger V (1997) Appl Phys Lett 70 3197... 

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