 Among Plowshare's many concepts was the Project PACER, which intended to produce electrical power from the explosions of nuclear weapons in caverns.Nuckolls was struck by the size of the caverns needed to contain the explosions, and began to wonder if they could be scaled down.The secondary relies on neutrons to carry out a chain reaction that converts lithium deuteride (LiD) into deuterium and tritium which then undergoes fusion.