Research and development activities are reported on Borax-V, ZPR-III No. 44, ZPR-VI No. 1, ZPR-IX, EBR-I, EBR-II, EBWR, Treat, Faret, Rapsodie Reactor, critical assemblies, fast reactors, Argonne Low Power Research Reactor, Topsy, Godiva, Argonaut Reactor, Argonne Advanced Research Reactor, Rocket Fuel Test Reactor, magnetohydrodynamic cells, and fuel cells. Reactor technology and investigations are reported in reactor physics, fuels and materials development, component development, heat engineering, and chemical separations. Nuclear safety development in thermal and fast reactors is discussed. (N.W.R.)