The chemistry of iodine in accident conditions

We report continued work on the oxidation of aqueous I-providing information for the assessment of hazards in reactor accidents with emphasis on experiments at low concentrations. H2O2 oxidises I-, in the presence of boric acid, with a rate constant 0.014 M-1s-1 at 250C and an activation energy 54 kJ/mole. Radiolysis of I-, concentration 10-6 to 10-1M, with boric acid and oxygen present, proceeded to a maximum conversion to I2 of the order 1%. Laboratory results were modelled by a scheme of radiolytic reactions which when applied to a reactor accident predicted a significantly greater conversion because of the large vapour to liquid volume ratio. (author)