Radioactive isotopes entrapped in cancrinite - to protect the environment, by reacting caustic liquor with clay and sodium nitrate

摘要

Caustic liq. radioactive scrap contg. sodium nitrate as solid relatively insoluble and heat stable cancrinite charged with salts is reacted with an aluminosilicate clay selected from kaolin, bentonite, dickite halloysite and pyrophillite at 30-110 degrees C to imprison the radioactive isotopes in the matrix of aluminosilicate and cancrinite. Radioactive isotopes such as Cs+, Sr++ etc (neutralised Purex waste) can be trapped in the matrix of a highly insoluble substance so that it can be buried deeply away from civilisation. Process is simple and does not need an external supply of heat. The clays used are relatively cheap and readily disposable. The leachability of the solid is of the order of 10-7-10-10g/cm-day.