Surface decontamination of primary circuit structures of IWW-2M reactor

A process is described of decontamination of surfaces of steel and aluminium alloy structures of the IVV-2M reactor primary circuit performed to improve the environmental radioactivity, to remove fuel material and radionuclides from deposits and to ensure normal conditions for maintenance operations. Problems of selecting decontamination method, radiometric and chemical analyses during decontamination are considered. Decontamination is performed as a two-stage process. Mixture containing 0.1% of Na2CO3 and 0.025% of B trilon is used as solution for the first stage, that of 0.1% of oxalic acid and 0.025% of B trilon - for the second stage. Upon decontamination a considerable improvement of the environmental radioactivity at the reactor has been observed. Specific activity practically of all radionuclides monitored in the coolant decreased by an order as compared to the activity for the period preceding decontamination