HAL : in2p3-00273035, version 1
 Journal of Nuclear Materials 373 (2008) 112-118
 Study of radiogenic helium diffusion in the β-thorium phosphate diphosphate ceramic
 A. Ozgümüs1, E. Gilabert2, N. Dacheux1, C. Tamain1, B. Lavielle2
 (2008)
 $\beta$-Thorium phosphate diphosphate polycrystalline ceramic is considered as a promising candidate for the immobilization of actinides in the field of a long-term storage. In order to study the behavior of the ceramic in relation with the evacuation of helium produced by actinides and daughters disintegrations, the release of radiogenic helium from a sintered pellet aged over an about six year period was studied by thermal desorption and high resolution mass spectrometry. The apparent diffusion coefficients are determined for different annealing sequences and are approximately the same for zircon and britholite at low temperature and uranium dioxide ceramic at high temperature. The apparent diffusion coefficients are found to be (7 ± 3) x 10^-22 m^2 s^-1 and (1.5 ± 0.5) · 10^-20 m^2 s^-1 at 20 °C and 120°C, respectively. The activation energy for the apparent diffusion process encompassing both volume and inter-granular diffusion is estimated at 45 ± 15 kJ mol^-1 in the studied temperature range (20–1020° C).
 Thème(s) : Physique/Physique/Chimie-Physique
 in2p3-00273035, version 1 http://hal.in2p3.fr/in2p3-00273035 oai:hal.in2p3.fr:in2p3-00273035 Contributeur : Suzanne Robert <> Soumis le : Lundi 14 Avril 2008, 12:00:27 Dernière modification le : Mardi 17 Juin 2008, 11:22:45