[en] A description of phase diagram of the U-N system is given. The technology of production of uranium nitrides is presented. Besides, the technological methods of core fabrication of uranium mononitride are described: sintering, hot pressing. Considered are physical and mechanical properties (heat capacity, heat and formation free energy, entropy, thermal conductivity and thermal expansion, electrical resistance, hardness, elastic properties, bending strength, thermal stability, creep and self-diffusion) and chemical properties (interaction with gases, water, acids, alkalis, metals, alloys and refractory compounds) of uranium mononitride. Uranium carbonitride properties are briefly described