Decontamination of nuclear graphite Original Research Article

Graphite is used in gas-cooled reactors (e.g. AGR, MAGNOX, HTR) and Russian RMBK reactors as a moderator and reflector. About 250,000 Mg of irradiated graphite (i-graphite) has to be considered as radioactive waste in the next few centuries. Fission products and activation of impurities in the graphite contaminate this graphite during reactor operation. Key nuclides for waste management are Co-60 during decommissioning, if decommissioning is performed immediately after reactor shutdown, and the long living radionuclides 14C and 36Cl for long-term safety in the case of direct disposal. Most radioisotopes can, in principle, be removed by using the purification methods already applied during the manufacture of nuclear graphite. However, due to the same chemical behaviour as 12C, this does not seem to be applicable to 14C.