Transport of uranyl ion across a supported liquid membrane made from Aliquat 336 in CHCl3 as the carrier was investigated from an aqueous feed containing hydrochloric acid. The transport rates were correlated with the pore size, carrier concentration, nature of organic carrier and the feed acidity. Maximum transport was observed for a carrier concentration of 30% (v/v) and a feed acidity of 6 M HCl. Significant transport of the feed acid was observed when Aliquat 336 was used as the carrier. Species of the type [R3R'N+]center dot[UO2HCl4-] appears to be transported along with the ion-pairs [R3R'N+](2)center dot[UO2Cl42-] and [R3R'N+]center dot[UO2Cl3-] which is responsible for the acid transport. The transport behaviour of several fission products obtained from an irradiated target of natural U was also investigated. Selective separation of U was possible from most of the radionuclides with the exception of Mo, Tc and I, whose permeation was <10%. A separation method for trace amount of U-233 from bulk thoriurn matrix was also developed which could find application in the processing THOREX feed solutions. (C) 2006 Elsevier B.V. All rights reserved.