FIELD: recovery of highly radioactive waste. SUBSTANCE: highly active concentrate is mixed up with zirconyl nitrate solution in molar proportion of (0.20- 0.35):(0.80-0.65) in terms of metal oxides and nickel nitrate solution is introduced in mixture. Quantity of introduced nickel nitrate in terms of metal nickel is at least molar amount relative to sum of zirconium dioxide and oxides of transplutonium and rare-earth elements. Mixture of solutions obtained is calcined and calcined product is subjected to hot molding in inert environment. Cermet block obtained is, essentially, zirconium-dioxide solid-solution cube stabilized by oxides of transplutonium and rare-earth elements dispersed in metal nickel matrix. EFFECT: improved heat conductance of cermet block which prevents its cracking in the course of long-time storage. 3 tbl
