Thorium was also abandoned because it could not be used to make atomic bombs. Production of bombs during the cold war required more nuclear reactors to create enriched uranium for bomb grade material. When the Soviet Union collapsed Nuclear power should have been abandoned in favor of thorium but the entrenched industry lobbied our elected leaders to keep thorium out and uranium in. The Thorium reactor was an experimental science project and just proved the theory that it could be made for commercial electrical generation.