Conditioning methods for beryllium waste from fusion reactors

Future fusion power plants will generate large quantities of neutron-irradiated beryllium. Although recycling is the primary waste management option for this material, considerable amounts of beryllium will require permanent geological disposal after an interim storage period of 50–100 years. For this waste, appropriate conditioning methods need to be developed. For technical beryllium grades irradiated in a fusion reactor the γ-dose rate and inhalation dose are, after a decay time of 100 years, dominated by transmutation products from impurities present in the metal. Assuming detritiation of the beryllium shortly after its service-life in the reactor, the main radionuclides contributing to γ-dose rate and inhalation dose are 60Co and actinides. In this paper, we discuss four conditioning methods: cementation, bituminisation, vitrification and phosphatisation. When comparing the different conditioning techniques, we place the emphasis on the long-term behaviour of beryllium in the chemical environment of the immobilisation matrix. From this exercise, vitrification resulted as a viable method to immobilise the beryllium waste.