Oxidation and hydrolysis of thorium doped uranium nitride fuel for use in LWR
Journal article, 2021

Uranium nitride is being investigated as a replacement for UO2 as it shows enhanced thermal properties and seems to be a promising accident tolerant fuel (ATF) candidate. The main drawback of UN fuel is its innate low oxidation resistance in air/water environments. This becomes a challenge for the implementation of UN fuel in water-cooled reactors. The effect of thorium doping in the stability of uranium nitride microspheres and pellets sintered by spark plasma sintering (SPS) was investigated in oxidizing environments using thermogravimetric analysis and autoclave testing. It was found that during oxidation in air the density had a noticeable effect, increasing the reaction onset temperatures in pellets with higher densities. In addition, thorium doping improved the oxidation resistance of pellets in air by increasing the maximal reaction rate temperature by approximately 50 K. However, this effect was almost nonexistent in highly porous doped microspheres. The interaction with water at 373 K showed that pellets manufactured using SPS can survive unchanged for at least six hours in boiling water, which is an improvement to cold-pressed pellets. At 473 and 573 K, the pellets were oxidized and disintegration into an oxide powder was observed. Thorium-doped uranium nitride pellets did not present any improvement with respect to the oxidation resistance of UN in water at these temperatures.

Porosity

Doped uranium nitride

Autoclave test

Oxidation

SPS

Theoretical density

Corrosion

Author

Luis Guillermo Gonzalez Fonseca

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Nuclear Chemistry

Marcus Hedberg

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Nuclear Chemistry

Teodora Retegan Vollmer

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Nuclear Chemistry

Journal of Nuclear Materials

0022-3115 (ISSN)

Vol. 555 153150

Subject Categories

Inorganic Chemistry

Ceramics

Materials Chemistry

DOI

10.1016/j.jnucmat.2021.153150

More information

Latest update

7/15/2021