Structural study of Pu1−xAmxO2 (x=0.2; 0.5; 0.8) obtained by oxalate co-conversion

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

“…It leads to a significant self irradiation inducing structural defects formation and lattice parameter expansion [5][6][7][8]. Besides, swelling phenomenon at the macroscopic scale is also observed [4][5][6][7][8][9].…”

“…In this study, we proposed a new description of the pellet diameter variation using the exponential relations (1) and (2) which are similar to that currently used to describe the lattice parameter expansion [4][5][6][7]. …”

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

“…The latter causes to a hundred of atomic displacements which are mainly located at the end of the a particle mean free path (10 mm). Thus, self-irradiation could lead to well-known phenomena at the structural scale such as amorphization [6], allotropic transitions [7], lattice parameter expansion [5,8,9], defect formation [10,11] and pellet swelling at the macroscopic scale [12]. These self-irradiation-induced phenomena were notably studied for MA-bearing fuels by X-ray Absorption Spectroscopy (XAS) and X-ray Diffraction (XRD) measurements [7,[13][14].…”

Lattice thermal expansion of Pu1−y Am y O2−x plutonium–americium mixed oxides

“…These two compositions were determined by calculation based on both the production date and isotopic composition of the two initial PuO 2 raw powders. The Pu 0.79 Am 0.21 O 2Àx , Pu 0.51 Am 0.49 O 2Àx , Pu 0.20 Am 0.80 O 2Àx and AmO 2Àx powders were produced by (co-)precipitation of the respective nitrate solutions with oxalic acid to form the associated oxalates and the associated Am/(Pu+Am) ratio was verified by chemical analysis (Arab-Chapelet et al, 2007;Jankowiak et al, 2008Jankowiak et al, , 2009Grandjean et al, 2009). The particles were heated in air in order to convert the oxalate into its respective oxide.…”

“…The particles were heated in air in order to convert the oxalate into its respective oxide. The Pu 0.79 Am 0.21 O 2Àx , Pu 0.51 Am 0.49 O 2Àx and Pu 0.20 Am 0.80 O 2Àx mixed oxide powders were prepared within the EUROTRANS program, FUTURE project (Jankowiak et al, 2008(Jankowiak et al, , 2009Delage et al, 2011;Staicu et al, 2015). Prior to this study, these three powders were pelletized and sintered to obtain dense samples of about 1 g.…”