Initial Activation Assessment for ARIES Compact Stellarator Power Plant

As the safety assessment frequently requires knowledge of the activation parameters, we estimated the highest possible activity, decay heat, and waste disposal rating on the time scale after shutdown for the compact stellarator power plant ARIES-CS. We selected two widely different systems employing SiC/SiC composites and low-activation ferritic steel (FS) as structural materials. Our results show that components of both systems qualify as Class C low-level waste (LLW) at the end of a 100 y storage period following the decommissioning of the plant. The SiC blanket, vacuum vessel, and magnet offer very low waste disposal rating to the extent that a Class A LLW seems achievable for these components. On this last point, we discussed the split between the Class A and Class C wastes, emphasizing our motivation to lower the level of ARIES-CS radioactive waste