Iodine-129 and carbon-14 are of lesser importance than many other radionuclides in nuclear waste management because of their relatively low radiotoxicity. Their safe immobilization and disposal, however, is a significant challenge because their chemical properties are quite different from most other components of nuclear fuel waste. The authors have sought thermodynamically defensible inorganic waste forms for both of these radioisotopes.

This paper discusses the stability and solubility of inorganic iodides as they relate to the selection of a waste form for iodine-129. The best candidates appear to be silver iodide (AgI), either alone or in combination with silver chloride (AgCl), and a combination of Bi₅O₇I and Bi₂O₃. Neither is completely satisfactory. The principal drawback of AgI is its relative ease of reduction. High chloride concentrations also increase the solubility of Agl, but it is insensitive to carbonate. The main disadvantage of bismuth oxyiodide is its susceptibility to displacement reactions with dissolved chloride and carbonate; also, it is unstable under strongly reducing conditions.