Abstract Scope |
The earliest development of nuclear energy and weapons required understanding the thermodynamics and phase equilibria of actinide and related systems, with references dating as early as 1943. Standard fluorite-structured UO<sub>2</sub> fuel is itself complex, exhibiting substantial hyper- and hypo-stoichiometry and has been the subject of modeling efforts for well over 50 years. That coupled with the generation of fission product elements, high temperatures and a steep thermal gradient, and radiation make it exceptionally challenging to thermochemically understand oxide fuel behavior. Similar comments can be made regarding the various alternative fuel systems explored over the decades, and some of which are being considered today in accident tolerant fuel options such as silicide, borides, nitrides, and carbides, metallic alloys, and molten salts. This paper will review thermochemical modeling of oxide fuels and remaining challenges, and explore the state of understanding for alternatives such as actinide silicides and molten salts. |