Utilization of irradiated graphite as embedding material for radioactive waste

摘要

About 200,000 tons of irradiated graphite (i-graphite) worldwide from nuclear fission reactors has to be managed as nuclear waste in near future. However the already performed work for the waste management of i-graphite from shows, that waste management of even low contaminated graphite could be expensive and requires special retrieval, treatment and disposal technologies for safe long term storage as low or medium radioactive waste. Graphite itself is a geologically stable material proven by its natural occurrence. However its porous structure does not allow the use of graphite as long term stable waste matrix for final disposal. Furthermore a slow corrosion in aquatic phases can be induced by high irradiation doses. The porous structure is related to large surface areas and therefore the radiation induced corrosions process cannot be neglected for final disposal. Furthermore aqueous phases will penetrate into the pore system and radionuclides adsorbed on the surface will be dissolved.