Thermal Energy Transport in Oxide Nuclear Fuel

Abstract

To efficiently capture the energy of the nuclear bond, advanced nuclear reactor concepts seek solid fuels that must withstand unprecedented temperature and radiation extremes. In these advanced fuels, thermal energy transport under irradiation is directly related to reactor performance as well as reactor safety. The science of thermal transport in nuclear fuel is a grand challenge due to both computational and experimental complexities. Here, we provide a comprehensive review of thermal transport research on two actinide oxides: one currently in use in commercial nuclear reactors, uranium dioxide (UO2), and one advanced fuel candidate material, thorium dioxide (ThO2). In both materials, 5Concluding Remarks .

Inferring relative dose-dependent color center populations in proton irradiated thoria single crystals using optical spectroscopy

“…2 Under coupled extremes of temperature, energetic particle bombardment, mechanical stress, or corrosive environments, the microstructure of these materials can rapidly evolve and lead to the formation of atomic level as well as extended structural defects. 8 These defects introduce distortions in the crystal lattice that act as scattering sites for phonons and can drastically alter thermal 9–11 and elastic 12 properties. Furthermore, the optical properties of metal oxides may also be dramatically affected by the presence of point defects.…”

Structural dynamics of Schottky and Frenkel defects in ThO2: a density-functional theory study

“…to the formation of defects, then it is reasonable to suggest that this may be benecial from a safety perspective compared to UO 2 . 88 Further research in this direction will require reliable means to identify and quantify defects in real materials and to assess their impact on the physical properties; modelling can play an important role in this, for example, as we have shown, by identifying spectral signatures that could be measured using routine spectroscopic techniques.…”

Advances in actinide thin films: synthesis, properties, and future directions

“…Several techniques have been used to measure the thermophysical properties of bulk actinide materials [4]. However, thin films have been targeted in specific cases as a means to increase measurement accuracy while using non-destructive techniques.…”

“…It is here where photothermal approaches offer a viable option for studying samples with small physical dimensions without damage to the sample or the need for destructive sample preparation approaches [95]. Several comprehensive reviews have been recently published on the thermophysical properties of actinide oxides [4], nitrides [96], and carbides [97,98] due to the importance of these compounds to nuclear science and industry.…”

“…They also exhibit divergent magnetic properties, from nearly magnetic (Np and Pu) to transition-metal-like behavior (Th, Pa, U) [2]. Technologically, the most widely used actinide compound to date has been UO 2 , in its role as the primary fuel for commercial nuclear energy production [3,4]. Despite these unique physical properties, their scarcity, inherent radioactivity, and challenges concerning their synthesis mean that actinide materials are still some of the least understood elements.…”