Stability study of iodine adsorbed on silver impregnated adsorbents for interim storage

To determine the stability of iodine adsorbed on silver impregnated adsorbents for interim storage, silver alumina, silver silica gel and silver zeolite have been tested for their resistance to volatilization and leaching. No iodine was removed from iodine loaded silver alumina and silver silica gel when these adsorbents were heated to 5000C, above 5000C, however, iodine was volatilized as AgI. For silver zeolite, physically adsorbed iodine was released at lower temperatures, but about 40% of the adsorbed iodine remained at 12000C. When iodine loaded adsorbent particles were in contact with water, iodine was leached out, mainly from the soluble AgIO3 in cases of silver alumina and silver silica gel, and from physically adsorbed iodine for silver zeolite. The silver alumina adsorbents were proved to be leach resistant when they were heated once to 4500C in order to decompose AgIO3 into insoluble AgI. This tendency was also observed when the adsorbents were immobilized in Portland cement. (author)