fissionable nuclear material in the form of fabricated elements for loading into the reactor core of a civilnuclear power plant or research reactor, fissionable material that has been enriched to a composition that will support a self-sustaining fission chain reaction when used to fuel a nuclear reactor, thereby producing energy (usually in the form of heat or useful radiation) for use in other processes, materjal, millest saab tuuma lõhustumise abil energiat toota