Design and criticality analysis of colloidal slurry nuclear reactors

A novel nuclear reactor concept is presented in this paper which can sustain the controlled fission reaction and has an innovative mechanism of reactivity control. The concept of this reactor is based on the stability of colloidal suspensions. These suspensions consist of colloidal fuel particles suspended in a moderator with a controllable separation distance. The packing factor of the colloidal suspension can be controlled by slightly modifying the ionic concentration of the suspension medium, effectively controlling the criticality of the reactor. Based on local average separation distance between particles, thermalization of neutrons can be varied and can be used to manipulate neutron multiplication factor k∞. Numerical calculations are performed with the help of MCNP software to obtain optimal configuration of critical assemblies. For the numerical case studies presented in this paper, uranium dioxide (UO2) fuel particles with size ⩾10 μm in different liquid solvents are considered. The fuel particles are simulated as hard spheres packed in Bravais lattice structures within the solvent medium. Simulations involve neutron interactions of a uniform colloidal suspension of spherical fuel elements of diameters 5 cm-0.001 cm. The homogeneous fuel equivalence was found to occur for particles sized below 0.010 cm diameter. Criticality curves are generated for fuel particle configurations with varying particle density, confirming fuel configurations can be controlled by only modifying particle packing factor. Additional criticality curves are generated for various cylindrical geometries of fuel suspension vessels with modular form factors. Triethylene glycol is substituted as a moderator and suspension fluid with higher boiling point as compared to water. The type of moderator or solvent does not have any significant impact on criticality performance.