UWFDM-1272 Three-Dimensional Neutronics Assessment of Dual Coolant Molten Salt Blankets with Comparison to One-Dimensional Results

Detailed three-dimensional (3-D) neutronics calculations have been performed for the dual coolant molten salt blanket designs. The model includes the detailed heterogeneous geometrical arrangement of the inboard (IB) and outboard (OB) blanket sectors. The total tritium breeding ratio (TBR) is ~1.07. The 1-D calculations tend to overestimate nuclear heating in the blanket by ~8% resulting in overestimating the plant thermal power. The approximate 1-D calculations overestimate damage and nuclear heating in the first wall (FW) and front zone of the blanket by factors of 1.3-1.7 but result in a steeper radial drop leading to significant underestimation (by up to a factor of 3) of nuclear parameters at the back. The 1-D calculations significantly underestimate radiation damage in the shield and vacuum vessel behind the blanket.