Kinetics analysis based on reactivity change mechanism obtained by Monte Carlo and CFD calculation for Windscale Works criticality accident

Fukuda, Kodai 

To clarify the possible criticality scenario of the Windscale Works criticality accident, a multi-physics analysis has been performed using the CFD toolbox OpenFOAM, the Monte Carlo neutron transport code Serpent2, and the point kinetics code AGNES2. The results show that the periodic wavy reactivity changes might have dominated the criticality, and there is a possible scenario with the number of calculated fissions consistent with the reported value.