Neutron absorber coatings for criticality control in annular tanks employed in spent fuel reprocessing

Computational analysis has been carried out to evaluate the effectiveness of neutron absorber coatings for criticality control in an annular tank used in fast reactor spent fuel reprocessing unit. The effect of composition, thickness and coating configuration for a given tank design and fuel solution concentration was evaluated on the basis of the multiplication factor (keff) calculated using the Monte Carlo N-Particle (MCNP) code. The neutron absorbers considered for the study were pure boron carbide (B4C), B4C/Ni–Cr combination and colmonoy. The effect of enriched boron was also analyzed. The results show that the coatings can enhance the storage capacity up to 30% for the annular tank studied.