Self-irradiation effects in dense and tailored porosity U1−yAmyO2−x (y=0.10; 0.15) compounds

Application of the UMACS process to highly dense U1−xAmxO2±δ MABB fuel fabrication for the DIAMINO irradiation

“…Dense and porous U 0.85 Am 0.15 O 2±d lattice parameters are respectively 5.468(1) and 5.473(1) Å, while those of U 0.925 Am 0.075 O 2±d dense and porous samples were found to be, respectively, 5.469(1) and 5.472(1) Å. These values are consistent with those previously reported for these materials [6].…”

“…This novel method for MABB fuel fabrication, based on conventional sintering, differs from that usually developed for MOX or MABB fabrications, as reactive sintering under a controlled atmosphere is traditionally employed to prepare such samples. The porous samples were fabricated following a process previously used for the MARIOS program [3][4][5][6][7] which offers a reliable way to prepare pellets exhibiting a high open-porosity ratio. As this process has been previously described, this paper first details the general description of the UMACS process and then briefly discusses the mechanism associated to the porous process (Part 2).…”

Melting behaviour of americium-doped uranium dioxide

“…However, because a delay of few weeks (for XRD) to a couple of months (for XAS) was inevitable between the laser heating/cooling treatments and the post-melting material characterisation, the samples underwent some self-irradiation damage, notably those with the highest Am content. This could be viewed as a partial explanation for the complex phase splitting and higher O/M ratio observed in the U 0.8 Am 0.2 O 2+d sample as several studies have shown that a-selfirradiation-induced structural effects on (U, Am)O 2 compounds are limited to lattice swelling reaching up to 0.8 vol.% and a small structural disorder increase [45,46,[52][53][54].…”

Alpha self-irradiation effect on the local structure of the U0.85Am0.15O2±x solid solution

“…Given above mentioned mean free paths of both Np nuclei and a particle, it is mainly possible to study damages associated to the emission of 237 Np nucleus. Regarding uranium-americium mixed-oxide fuels, a first Positron Annihilation Lifetime Spectroscopy (PALS) study showed the presence of vacancy-type defects due to the cumulative decay dose [15,16]. It was also shown that self-irradiation implies at the macroscopic scale important changes such as fuel swelling.…”