Literature Survey: Methods for the Removal of Iodine Species from off-Gases and Liquid Waste Streams of Nuclear Power and Nuclear Fuel Reprocessing Plants, with Emphasis on Solid Sorbents

摘要

Emphasis was focused on the operating parameters that most strongly affected the optimization of the processes used to treat actual process or feed streams which simulated actual compositions occurring at nuclear facilities. These parameters included gas superficial velocity, temperature, types of organic and inorganic contaminants, relative humidity, iodine feed-gas concentration, iodine species, column design (for both acid-scrub and solid sorbent-based processes), sorbent particle size, run time, intense radiation (solid sorbents only), and scrub-acid concentration. The most promising acid-scrub process for removal of iodine species from off-gases appears to be Iodox. The most promising solid sorbent for removal of iodine species from off-gases is the West German Ag-KTB--AgNO sub 3 -impregnated amorphous silicic acid. The tandem silver mordenite--lead mordenite sorbent system is also quite attractive. Only a limited number of processes have thus far been studied for removal of iodine species from low-level liquid waste streams. The most extensive successful operating experience has been obtained with anion exchange resins utilized at nuclear power reactors. Bench-scale engineering tests have indicated that the best process for removal of all types of iodine species from liquid waste streams may be treatment on a packed bed containing a mixture of sorbents with affinity for both elemental and anionic species of iodine. 154 references, 7 figures, 21 tables. (ERA citation 04:018090)