This paper investigates the dynamics of a postulated criticality in a powder used as part of fuel processing. Numerical simulations are performed in 2D and 3D geometries in which layers of MOX, UO2 and zinc stearate (acting as a moderating lubricant) powders become supercritical. The system simulated here were initialised with a step reactivity insertion of 1$, 2$ and 5$. The coupled radiation and multiphase–multicomponent simulations showed complex dynamics with an increase of powder temperature and mixing of the moderator into the MOX.
Gomes, J. L. M. A., Pain, C. C., Eaton, M. D., Goddard, A. J. H., Piggott, M. D., Ziver, A. K., de Oliveira, C. R. E., & Yamane, Y. (2008). Investigation of nuclear criticality within a powder using coupled neutronics and thermofluids. Annals of Nuclear Energy, 35(11), 2073-2092. https://doi.org/10.1016/j.anucene.2008.05.012