Properties of Novel Selective Ion Exchangers for Nuclear Plant Applications

A new family of ion exchange and sorption media has been developed and applied for the removal of radioactive contaminants from aqueous streams in nuclear power plant operations. The general principle in the development of these materials is optimization of their selectivity for species that significantly contribute to the radioactivity of these streams (e.g., cesium, iodine, and cobalt) in the presence of a large excess of other ions (e.g., sodium, potassium, magnesium, calcium, chlorine, and SO₄). This results in improved effective capacity and service lifetime of these new materials compared with the performance of conventional broad-spectrum ion exchange resins. Other advantages include higher decontamination factors, shorter contact times, greater stability, and convenience of disposals. Examples of the new materials include Durasil 10, a high-capacity ion exchange medium for cesium and strontium, and Durasil 60 and 70, which are highly effective in the removal of iodine and cobalt, respectively. The performance of these new media has been characterized in laboratory studies, engineering-scale demonstration tests, and 1 to 2 yr of experience with the Durasil media in routine waste-water treatment in several nuclear power plants.