Project PACER, carried out at Los Alamos National Laboratory (LANL) in the mid-1970s, explored the possibility of a fusion power system that would involve exploding small hydrogen bombs (fusion bombs)—or, as stated in a later proposal, fission bombs—inside an underground cavity. Its proponents claimed[1] that the system is the only fusion power system that could be demonstrated to work using existing technology. It would also require a continuous supply of nuclear explosives and contemporary economics studies[2] demonstrated that these could not be produced at a competitive price compared to conventional energy sources.