Progress is reported on development of liquid metal and water cooled reactors. Details are included concerning the EBWR, Borax V, ZPR-III, ZPR-VI, AFSR, EBR-I, EBR-II, and FARET. Developments in general reactor technology are reported in applied reactor physics, reactor fuel and components development, heat engineering, and chemical separations. Advanced systems research and development was devoted to the Argonne Advanced Research Reactor and a conduction- cooled reactor to substitute for isotope heat sources. Safety studies are reported on thermal and fast reactors. (J.R.D.).