Studies on the Radiation Stability of Several Polymeric Flat Sheets used for Actinide Ion Separation from Radioactive Feeds

Membrane based separation methods have been used for the remediation of industrial waste water emanating from a large number of industries. The major challenge in such studies has been the membrane fouling which arises due to a large number of suspended particles. In view of the highefficiency of the membrane based separation systems, attempts are made, oflate, to employ them in the nuclear industry for radioactive waste streams aswell. The radioactive wastes are categorized as low, medium and high level wastes depending on their radioactivity content. Though low level wastes have been treated by membrane based separation methods at large scales, it is really a challenge to employ membrane separations to high level wastes.

This is due to the large amount of radiation dose prevailing in the high level waste mainly due to the high beta gamma containing isotopes such as 137Cs and 90Sr. Secondly, most of the membrane based separation methods employ polymericmembranes which are highly susceptible to radiolytic degradation. Radioactive waste management is one of the major challenges of the nuclear power program and there are reports on the application of membrane based separation methods for the separation of actinide and fission product nuclides from radioactive wastes. Though low level wastes have been treated using polymeric membranes, the latter can be reused and recycled for a significantly long period of time due to the low dose rates (<microcuries per litre of the waste solution) of these wastes. On the other hand, high level waste processing can be done using radiation resistant polymers.