Oxygen diffusion in uranium-plutonium oxide fuels at low temperatures

Self-radiation damage in plutonium and uranium mixed dioxide

“…In addition, the difference might be explained by the fact that MOX is composed of many cations having various ionic radii as discussed below. Table 6 compares activation energies which correspond to thermal recovery of lattice expansion in MOX obtained in this study, thermal recovery of point defects in UO 2 [18][19][20][21][22] and diffusion of oxygen, uranium and plutonium ions in MOX [23][24][25]. As shown in Table 6, uranium interstitial type defects can be annealed around 763 K with an activation energy of 0.1-0.4 eV and oxygen ions can migrate with an activation energy of 0.2-0.7 eV in the temperature range from 473 to 1273 K. Since the lattice defects in the first recovery stage can be completely recovered at temperatures below 673 K with low activation energy of 0.12 eV, the first recovery stage is considered to correspond to the recovery of anion Frenkel defects that can be easily annihilated with the lowest activation energy among the three kinds of defects noted above.…”

Oxygen diffusion in the fluorite-type oxides CeO2, ThO2, UO2, PuO2, and (U, Pu)O2

“…Previous studies have measured oxygen self-diffusion and chemical diffusion coefficients (Watanabe et al, 2017;Vauchy et al, 2015;Sari, 1978;Murch and Catlow, 1987;Lorenzelli and El Sayed Ali, 1977;Kato et al, 2013;Kato et al, 2009;Garcia et al, 2010;Deaton and Wiedenheft, 1973;D'Annucci and Sari, 1977;Contamin et al, 1972;Breitung, 1978;Belle, 1969;Bayoglu and Lorenzelli, 1984;Bayoglu and Lorenzelli, 1979;Auskern and Belle, 1961;Ando et al, 1976;Watanabe and Kato, 2012;Kim and Olander, 1981;Floyd, 1973;Kamiya et al, 2000;Millot and Mierry, 1985;Gotte et al, 2007). The oxygen diffusion coefficients data set used in this review is shown in Table A1.…”

“…The data were measured using various methods, such as the isotope method, thermogravimetry, electrical conductivity measurement, and thermal dilatometry. It was difficult to assess changes dependent on temperature and O/M ratio because the data were scattered (Floyd, 1973;Gotte et al, 2007;Kamiya et al, 2000;Millot and Mierry, 1985;Ando et al, 1976;Dornelas and Lacombe, 1967;Matzke, 1987;Ligeon et al, 1970;Dorado et al, 2011;Lay, 1970;Bittel et al, 1969;Ruello et al, 2004;Kato et al, 2013;Mullins, 1972;Deaton and Wiedenheft, 1973;Bayoglu et al, 1983;Bayoglu and Lorenzelli, 1979;Chereau and Wadier, 1973;Bayoglu and Lorenzelli, 1980;Bayoglu and Lorenzelli, 1984;D'Annucci and Sari, 1977;Kato et al, 2009;Watanabe et al, 2017;Watanabe et al, 2020;Vauchy et al, 2015).…”