Separation Technology for Radioactive Iodine from Off-Gas Streams of Nuclear Facilities

Iodine separation technology using an inorganic adsorption material has been investigated in order to apply the technology to the off-gas treatment systems of nuclear facilities. Iodine removal efficiencies were checked by laboratory experiments using simulated off-gas streams of various conditions and the developed adsorbent, silver impregnated alumina (AgA). Laboratory test results demonstrated effective iodine removal with high decontamination factors (DF's) at relatively high temperatures (≥100°C). Then the removal efficiency were confirmed using actual off-gas streams sampled from the dissolver off-gas treatment system of the Karlsruhe reprocessing plant. The DF's were over 103 with the AgA bed depth of 10 cm and showed little change during the adsorption period, which indicated applicability of the iodine removal technology with AgA to nuclear fuel reprocessing plants. Iodine adsorption capacity and its release property were also investigated using simulated off-gas streams. The former had a value o...