Thermal expansion measurement of (U,Pu)O2-x in oxygen partial pressure-controlled atmosphere

Thermal and mechanical properties of CeO2

“…Development of nuclear fuel materials and processes requires assessment of numerous properties that govern thermodynamic stability, heat transport, and other factors. Many recent examples exist to demonstrate such efforts to characterize PuO 2 and mixed actinide oxides such as (U,Pu)O 2 . Cerium dioxide has historically been considered as a surrogate due primarily to its 3+ and 4+ valence states, which match the readily accessible oxidation states of Pu .…”

Optimization of a new interatomic potential to investigate the thermodynamic properties of hypo-stoichiometric mixed oxide fuel U1−y Pu y O2−x

“…We did however find several papers giving experimental lattice parameter data and associated recommendations for hypo-stoichiometric MOX at room temperature. The most reliable references in the literature are from Schmitz et al [38], Philipponneau [39], Harding et al [40], Benedict et al [41], Omichi et al [42] and Kato et al [43]. Belin et al [44] have measured lattice parameters of hypo-stoichiometric MOX from 298 K to 1750 K using in situ high temperature X-ray diffraction (XRD) for Pu contents of 0.14, 0.24, 0.35, 0.46, 0.54 and 0.62 but the O/M ratio of their samples during the measurements are unknown.…”

“…The effect of stoichiometry on thermal expansion of MOX has been investigated using thermal dilatometry measurements in a recent study from Kato et al [43] for Pu contents of 0.30 and 0.48, in a temperature range from 1400 K to 1950 K and for three O/M ratios (1.99, 1.98 and 1.97). Kato et al [43] have controlled oxygen partial pressure by adjusting the hydrogen partial pressure to moisture partial pressure ratio in a Ar/H2/H2O gas mixture to hold a constant oxygen to metal ratio in the U1-yPuyO2-x during the measurement. The O/M ratio in their study was stated to be stable during the measurement, and uncertainty was estimated to be ± 0.004 for the variation of the O/M ratio during measurements.…”

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

“…More precisely, thermal expansion behaviour is a key property for evaluating fuel-cladding interactions under irradiation (Fee & Johnson, 1981;Crawford et al, 2007;Olander, 2009;Gué neau et al, 2012;Lee et al, 2013). Since most of the current nuclear reactors operate with uranium dioxide or uranium-plutonium mixed oxide fuel (known as MOX), thermal expansion of these materials has been investigated for decades (Baldock et al, 1966;Martin, 1988;Momin et al, 1991;Yamashita et al, 1997;Tsuji et al, 2002;Uchida et al, 2014;Kato et al, 2016). To our knowledge, no similar studies have been performed on plutonium-americium mixed oxides, probably as a result of both the scarcity of these samples and the intrinsic difficulty in handling such radiotoxic MA-bearing solids in a glove-box.…”