Improving of bearing capacity of ceramics with a limited plasticity in a broad tem­perature range should be done taking into account operation parameters. For fuel elements of the first sections of the HRA operating in the brittle-damage temperature range, it is necessary first of all to decrease the defectiveness of ceramic using various hardening methods capable to elevate the strength. Optimizing hardening methods by modification of stressed surface state the strength of elements can be enhanced up to 100% (Table7.1).

The optimal choice of the parameters of traditional isothermal sintering of ZrC samples in different media (hydrogen, argon, and vacuum) allows achieving a high density (not less than 95%) and the bending strength about 550MPa at sintering temperatures 2,500-2,700K [2, 14].