Progress in nuclear safety research and development is reported. Topics covered include: reactivity effects of fuel displacements in a pool-type reactor, release of fission products on out-of-pile melting of reactor fuels, release of fission products on in-pile melting of reactor fuels, fission product transport evaluations, characterization and control of accident-released fission products, nuclear safety pilot plant, preparation of reactor containment hardbook, and radiochemical plant safety studies. (M.C.G.)