Most PWR stations have experienced leakages of boric acid and oil into liquid radwaste systems. Typically, these wastes have been concentrated by an evaporator system. Based on operating plant experiences, boric acid and oil are the majority of the solid loading for disposal and tend to decrease the efficiency significantly. The objective of these studies is to develop pretreatment techniques for the recovery of boric acid and for the removal of oil from such wastes for improving the evaporator performance. To these objectives, lab. scale reverse osmosis (RO) membrane and filtration/coalescence processes are introduced, which can separate boric acid and oil into waste streams. (Author).