Removal of technetium-99 and iodine-129 from alkaline radioactive wastes remaining from weapons processing is necessary as these radionuclides are long-lived and environmentally mobile in their most stable chemical forms (TcO4- and I-). Technetium-99 and iodine-129 are ill-suited to thermal processing because of the volatility of their high-temperature species. Resins based on Aqueous Biphasic Extraction Chromatography, ABEC, selectively extract TcO4- and I- from alkaline radioactive wastes and offer the advantage that stripping is accomplished by eluting with water. To date, most studies of ABEC resins have been performed using materials designed for analytical separations that are not suitable for process-scale applications. The development of ABEC resins compatible with a large-scale chromatographic apparatus is reported. ABEC resins of 50-100 mesh size showing <10% swelling during crossover from a 4 M NaOH load to a water strip and volume distribution ratios for pertechnetate as high as 160 have been synthesized, and their properties are discussed.