Technology for the reduction of highly radioactive waste from spent nuclear fuel. In ADTT, the proton beam created by the accelerator is aimed at a heavy atom target (e.g., tungsten, lead, or depleted uranium). The heavy nuclei are excited and emit bursts of neutrons during deexcitation. This process is called spallation. The spallation target is surrounded by a blanket from spent fuel material. Neutrons can induce fission in such material, transmuting it into shorter-lived or even stable isotopes. This process could generate energy and reduce the number of long-lived radioisotopes in nuclear waste. This technology is still in development.