TRIGA is a class of small nuclear reactor designed and manufactured by General Atomics. The design team for TRIGA, which included Edward Teller, was led by the physicist Freeman Dyson. Dyson says it may be one of the few reactors that ever made a profit for the company that made it, and that many research hospitals have them. Seventy exist worldwide.TRIGA is the acronym of Training, Research, Isotopes, General Atomic.