The electrical resistivities of polycrystalline samples of La, Pr, Nd, and Sm are reported in the temperature range 1.3 to 300 deg K. La exhibits a superconducting transition at 5.8 deg K. The curve for Pr has slope changes at 61 and 95 deg K. The Nd curve shows small jumps at 5 and 20 deg K. Sm shows slope changes at 14 and 106 deg K. (auth)

Safety precautions utilized for control and cominement of fissionable and radioactive materials in the various aqueous reprocessing operations performed at the Idaho Chemical Processing Plant are presented. Three primary nuclear safety controls, geometrical, mass limitation, and concentration control, are used. Operations are penformed according to standard operating procedures which are set up to prevent circumvention of the primary nuclear safety controls. The various processing operations with their particular safety features are discussed. The operations include receipt, handling, and storage of irradiated fuel elements, dissolution of the fuel elements in various reagents, separation of the unburned fissionable material from fission products and fuel element structural materials by solvent extraction, salvage or recycle operations of off- specifications product or waste solutions that exceed the dispossble fuel concentrationalimits, product packaging, storage and shipment, fission product recovery, and waste collection, handling and disposal. The originai plant design and later additions and modifications included built-in geometrical control wherever practical with allowances for possible neutron interaction between vessels. The standard operating procedures specificaily state mass limits and concentration controls required for certain operations which involve appreciable quantities of uranium. Administrative control insures compliance with the standard operating procedures. (auth)