Identification of iodine species released from fuel using a commercial volatile radioiodine species sampler

Experiments have been carried out to verify the manufacturer's claims for an iodine species sampler which differentiates between I2, CH3I and HOI, the main volatile forms of iodine expected in nuclear installations after radioactive releases from fuel. This sampler consists of five components: a filter paper to retain particulates; CdI2 on a matrix of chromosorb-P to retain I and I2; iodophenol on a matrix of activated alumina to retain HOI; 30-50 mesh silver zeolite for CH3I; and lastly 40-50 mesh TEDA-impregnated (5%) charcoal to capture any iodine which escapes the preceding filter elements. Calibration experiments used radioactively labelled CH3I and I2. 95% of the methyl iodide was trapped in the silver zeolite, and 87% of the I2 in the CdI2. These figures are almost identical to those of the manufacturer