Transient interactions of boron carbide with molten uranium oxide

0547884 - ÚACH 2022 RIV NL eng J - Journal Article
Journeau, C. - Kiselová, M. - Pozniak, I. - Bezdička, Petr - Svora, Petr - Šubrt, Jan - Bechta, S.
Transient interactions of boron carbide with molten uranium oxide.
Nuclear Materials and Energy. Roč. 29, DEC (2021), č. článku 101078. E-ISSN 2352-1791
Institutional support: RVO:61388980
Keywords : Severe Accident * Sodium-cooled Fast Reactor (SFR) * Uranium dioxide * Boron carbide * Molten pool * Aerosol release
OECD category: Inorganic and nuclear chemistry
Impact factor: 3.037, year: 2021
Method of publishing: Open access

Thermodynamic equilibrium calculations have shown that, at the elevated temperatures anticipated during se-vere accidents, uranium oxide-boron carbide interactions are likely to result in significant boron volatilization and the formation of uranium borides. This interaction is further investigated through transient experiments whereby boron carbide pellets are submerged in uranium dioxide melts held at elevated temperatures beneath inert atmospheres. X-ray diffraction and electron-microscopy analyses revealed the aerosols generated by the interaction to be rich in boron sesquioxide (B2O3) and uranium oxide. The solidified melt ingots recovered post-test exhibited highly heterogeneous chemistry with some samples richer in UO2 and others richer in U3O8. Thermodynamic equilibrium calculations indicate that this could be explained by heterogeneity in redox envi-ronment. The second, larger-scale, interaction, with an increased boron inventory, indicated uranium oxideboron carbide reaction formed either uranium boride or uranium borocarbide.
Permanent Link: http://hdl.handle.net/11104/0324050