METHOD AND DEVICE FOR RECOVERING ALKALI METAL CONTAMINATED WITH RADIOACTIVE IMPURITIES Russian patent published in 2003 - IPC

FIELD: nuclear power engineering; disposal of liquid alkali-metal coolants. SUBSTANCE: method includes mixing of molten alkali metal in inert atmosphere with dispersed inorganic oxidizing agent taken in ample amount compared with that required for oxidation, mixture heating, and cooling of end product. Mixture is heated to 200 C. Composition of ferric, silicon, aluminum, and calcium oxides is used as oxidizing agent, their proportion in composition being 40-55, 34-36, 5-6, and 4-16 mas.%, respectively. Granular slug produced in heavy nonferrous metal manufacture may be used as oxidizing agent. Mixture may be heated due to pre-heating of molten metal and/or oxidizing agent. Device implementing this method has heating chamber incorporating heater and crucible, alkali metal supply system, curing agent supply system, and gas control system. Heating chamber has top and bottom parts interconnected through sealed joint for separation. Bottom part of heating chamber designed for crucible installation is free to move and has at least two degrees of freedom. Its top part is fixed in position and communicates with alkali metal and curing agent supply systems. Heating chamber is also equipped with curing agent batcher and gate valve installed under curing agent batcher. In some cases alkali metal supply system may be provided with alkali metal batcher and heater. EFFECT: enhanced reliability of preventing formation of radioactive alkali solutions and explosive products in alkali metal recovery; reduced volume of end product; enhanced capacity of wasteless recovery process. 5 cl, 3 dwg