Dopant solubility and lattice contraction in gadolinia and gadolinia–chromia doped UO2 fuels

Lattice contraction and lattice deformation of UO 2 and ThO 2 doped with Gd 2 O 3

“…The contraction determined in the present study agrees well with the observations of Leyva et al [6], Hirai et al [7] and, except for one measurement, also with the observations of Ohmichi et al [2]. The observations of Fukushima et al [5] and Cardinaels et al [3] show a slightly lesser contraction as function of the Gd concentration. The data set of Durazzo et al [4] deviates substantially from the other data sets.…”

“…[2] also agree with our data set and those of Leyva et al and Hirai et al The results of Cardinaels et al[3] and Fukushima et al[5] show a slightly lesser lattice contraction. A possible reason for the lesser lattice contraction in the latter two studies may be attributed to the fact that the samples of Cardinaels et al contained non-negligible amounts of free UO 2 and the sintering conditions of Fukushima et al were highly reducing (Ar-8% H 2 ) and were analyzed without post-sintering oxygen equilibration.…”

“…4). [3] À16.2 ± 0.1 0.9999 Durazzo et al [4] À16.0 ± 0.1 0.9956 Fukushima et al [5] À16.9 ± 0.2 0.9991 Leyva et al [6] À17.5 ± 0.3 0.9991 Hirai et al [7] À17.9 ± 0.7 0.9939 a Restriction is made to the stoichiometric data set. The X-ray diffraction analysis of the (Th 1Àx Gd x )O 2Àx/2 series evidences that the fluorite lattice parameter continues to contract linearly until the limiting concentration of the solid solution (see Fig.…”

Synthesis of UO2 and ThO2 doped with Gd2O3

“…4). The observed lattice contraction with increasing gadolinium doping is as expected [36,38,39,48].…”

Cubic Phases in the Gd2O3-ZrO2 and Dy2O3-TiO2 Systems for Nuclear Industry Applications

“…This is controlled by using burnable neutron absorbers or neutron poisons, that is, by inclusion into the fuel assembly materials with a large neutron cross section. If the absorbers are incorporated directly into the fuel, they are called continuous or homogeneous [1,2]. When the burnable neutron absorbers are dispersed into an inert matrix, they are called discrete or inhomogeneous and they are distributed among the fuel pellets.…”