Activitiee are described in an investigation to develop refractory U materiala for superior reactor fuels. Uranium carbide was prepared by cold pressing in pellets with densitier of 92 to 96% of theoretical. Uranium nitride was synthesized, and it was found that dense specimens (95% of theoretical) could be obtained in N-deficient powder, however in stochiometric compositions the maximum density obtained was 85% of theoretical. In other work dense uranium silicide was prepared and several properties of UC, UN, and U/sub 3/Si/sub 2/ were studied. (J.R.D.)