Investigation of the formation possibilities of alkyl iodides in nuclear power plants

The radiolytic decomposition of ion-exchange resins used in Czechoslovak nuclear power plants for the purification of the reactor coolant and chemical control of H3B03 concentration in the coolant was studied with regard to the determination of sources of aliphatic hydrocarbons, which are potential precursors of alkyl iodides. On irradiation of ion-exchange resins in deaerated borate solution, C1-C4 hydrocarbons are formed. These hydrocarbons are produced also in the radiolysis of the emulsion of turbine oil in the same solution. The radiation stability of cation-exchange resins is higher than that of anion-exchange resins. Radiolytic and thermal reactions occuring in the gaseous mixtures containing I2, CH4, H20, and air/Ar give rise to CH3I. CH3I is produced also in the radiolysis of aqueous solutions containing CH4 and I2 or I-. (author)