Waste arising from dismantling operations: melting contaminated scrap iron

The 'Institut de Protection et de Surete Nucleaire' (IPSN) assessed the safety of melting operations for contaminated scrap iron which are carried out in an arc furnace with a capacity of 15 tonnes, located at Marcoule. The 'Unite de Demantelement des Installations Nucleaires' (Unit for Nuclear Installations Dismantling) of the CEA 'Direction du Cycle du Combustible' (Fuel Cycle Direction), is responsible for operating this furnace. To day, more than 5,000 tonnes of radioactive iron have been melted, of which 4,000 tonnes resulted from the dismantling of the coolant systems (CO2) and the auxiliary equipment of the G2 and G3 reactors. Initially, the iron was cast into 25 kg ingots and into 4 tonne blocks which were placed in interim storage in the G2 and G3 facilities. Then, the scrap iron was made directly into either biological shielding or into cast iron containers for packaging highly radioactive waste. The radioactive spectrum of scrap iron from dismantling of the G2 and G3 reactors was composed of 60Co (95%) and 137Cs. (author)