 In the mid-1970s, Project PACER, carried out at Los Alamos National Laboratory (LANL) explored the possibility of a fusion power system that would involve exploding small hydrogen bombs (fusion bombs) inside an underground cavity.As an energy source, the system is the only fusion power system that could be demonstrated to work using existing technology.It would also require a large, continuous supply of nuclear bombs, however, making the economics of such a system rather questionable.