Development progress is reported on fast reactors, liquid metal cooled reactors, ZPR-III, ZPR-VI, ZPR-IX, Borax-V, Faret, EBR-I, EBR-II, Treat, Fermi Fast Breeder Reactor, critical assemblies, Argonne Fast Source Reactor, EBWR, Argonne Advanced Research Reactor, magnetohydrodynamic cells, fuel cells, and boiling water reactors. Reactor technology is reported on fuel development and properties, physics, heat engineering, materials development, chemical separations, nuclear safety, and nondestructive testing. (N.W.R.)