Speciation of radionuclides in low-salinity liquid radioactive wastes (LRW) formed in the course of reprocessing and storage of radioactive wastes at the Radon Moscow Research and Production Association was studied. 137Cs is present in LRW mainly in the ionic form; α-emitting radionuclides, in the colloidal form; and 90Sr, in both colloidal and ionic forms. Coagulation methods with FeCl3 and methods of peroxide and permanganate oxidation were tested for removing organic substances from LRW. A two-step reverse-osmosis apparatus was tested for removing the major fraction of radionuclides and salts from the LRW. Laboratory experiments on sorption refinement of the permeate from the first step of reverse osmosis were performed with ionexchange resins and an NZhS type ferrocyanide sorbent. A new flowsheet for a water-treatment installation (WTI), allowing considerable reduction of the volume of secondary radioactive wastes, was suggested. The WTI was put into operation in 2010.