MINUTE FUEL ELEMENT OF SPACE-BASED NUCLEAR POWER PLANT

FIELD: physics, nuclear physics. ^ SUBSTANCE: invention is related to the field of nuclear power engineering and may be used in ultrahigh-temperature space reactors. Minute fuel element comprises microsphere of oxygen-free uranium fuel and four-layer protective coating, in which the third layer from microsphere is made of zirconium carbide or niobium carbide, and there is layer of zirconium nitride. The first protective coating layer from microsphere is made of zirconium nitride with columnar structure oriented in radial direction. The second and fourth layers are made from composition zirconium carbon-carbide with content of carbon phase that monotonously changes by radius within the limits of (5-10) wt % - (90-95) wt %. Carbon phase content makes (5-10) wt % at the borders of the second and fourth layers with the third layer. ^ EFFECT: improved corrosion resistance of power coats from zirconium or niobium carbides, which provides for prolongation of operation resource both in stationary radiation conditions and in heat cycling conditions with forced energy release.