Waste classification assessment of nuclear steels for fusion power applications

Abstract

Fusion power is an attractive option for the world's future energy needs. An important goal for fusion is to avoid the severe radioactive waste issues associated with nuclear fission. However, the neutrons produced in the fusion plasma reaction impinge on the surrounding reactor structure causing nuclear activation. It is hoped that activated material from fusion facilities can be disposed of as low level waste 50-100 years after operation ceases, but recent work suggests this may be difficult to achieve. This work presents inventory simulations for a number of potential fusion steels, for two neutron irradiation conditions typical of the DEMO reactor concept. The results are used to determine if the steels meet low level waste regulations, for a number of different international waste management systems. These results show that steels do not appear able to consistently meet low level waste requirements when exposed to near-plasma neutron fluxes. They have more success when exposed to lower fluxes, but traditional steels will still struggle to meet low level waste requirements in a fusion environment.