Membrane technologies for liquid radioactive waste treatment

The paper deals with some problems concerning reduction of radioactivity of liquid low-level nuclear waste streams (LLLW). The membrane processes as u ltrafiltration (UF), seeded ultrafiltration (SUF), reverse osmosis (RO) and membrane distillation (MD) were examined. Ultrafiltration enables the remo val of particles with molecular weight above cut-off of UF membranes and ca n be only used as a pre-treatment stage. The improvement of removal is achi eved by SUF, employing macromolecular ligands binding radioactive ions. The reduction of radioactivity in LLLW to very low level were achieved with RO membranes. The results of experiments led the authors to the design and co nstruction of UF+2RO pilot plant. The. development of membrane distillation improve the selectivity of membrane process in some cases. The possibility of utilisation of waste heat from cooling system of nuclear reactors as a preferable energy source can significantly reduce the cost of operation.