Void reactivity and pin power calculation for a CANDU cell using the SEU-43 fuel bundle

The CANDU type reactors have the ability to accommodate a wide variety of fuel types. For all the used fuel types the void coefficient of the reactivity is positive. In our paper a heterogeneous two-stratified coolant model is used for SEU-43 fuel bundle type. This is slightly enriched uranium (near 1%) with 43 fuel rods developed in INR Pitesti. The coolant is treated as a two-phase (liquid and vapour) medium, gravitationally separated. Eigenvalues are computed with the transport code CP_2D at different void fractions and burnup points. For the fresh fuel the MCNP results on the two-startified model a homogeneous model is used to benchmark CP_2D results.