EXTRACTION OF URANIUM NITRIDE PELLETS DURING EXTRACTION OF LEAD FROM BREST REACTOR FUEL-ELEMENT SIMULATORS BY MELTING

摘要

Spent fuel from the BREST-OD-300 fast reactor, which is now under development, is supposed to be reprocessed directly at the nuclear power plant by a water-free technology. The first operation is separation of the fuel (uranium and plu-tonium mononitride pellets) from the jacket. In BREST-OD-300 reactor fuel elements, the gap between the fuel pellets and the steel jacket is filled with lead. There are several known methods for separating the stainless-steel jacket from ceramic pellets: mechanical cutting, melting steel at 1500℃, and dissolving steel jackets in low-melting metal melts. Mechanical cutting of fuel elements filled with congealed lead will not separate the fuel and the jacket. Melting a steel jacket requires high temperatures and, aside from large amounts of energy and technical difficulties, it will lead to vaporization of the lead and premature destruction of the fuel. Dissolving in zinc will complicate the technology for opening fuel elements and will result in additional wastes.