SILICA GEL-BASED SORBING AGENT FOR RADIOIODINE RECOVERY Russian patent published in 2009 - IPC G21F9/02 B01J20/22 

FIELD: physics; nuclear physics.

SUBSTANCE: invention relates to production of sorbing agents for volatile radioiodine recovery and is designed to prevent the radionuclide release into environment during normal operation of nuclear power plants, as well as in case of nuclear accidents. Also, sorbing agent may be used to remove volatile radioiodine componds from steam-air streams in spent nuclear fuel reprocessing. Granulated inorganic absorbent is prepared from macroporous silica gel silver-impregnated by treating it with silver nitrate aqueous solution. Total silver content in absobent is 3-7 wt %. 30-70% of silver is reduced to metal by nitrogen-containing bases. The following reagents may be used as nitrogen-containing bases: hydrazine hydrate, hydroxyl amine or salts thereof, ammonia. Advantages of the absorbent are as follows: highly efficient sorption of volatile radioiodine compounds, including methyl iodide, from steam-air streams, i.e. reliable containment; heat resistance up to 300°C; sorption properties retained after contact with water; utilisation of commercially available coarse silica gel "КСКГ", which is widely used for various sorbing agents and catalysts production.

EFFECT: highly efficient sorption of volatile radioiodine compounds, including methyl iodide, from steam-air streams, ie reliable containment; heat resistance up to 300°C; sorption properties retained after contact with water; utilisation of commercially available coarse silica gel "КСКГ", which is widely used for various sorbing agents and catalysts production.

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