Many young American scientists and engineers worked for and studied under these nuclear pioneers. Truman's decision to transfer this research from military to civilian control made it possible for those scientists and their young proteges to focus on non-military research . For those studying the nuclear chain reaction, that meant research into peaceful uses of the atom, particularly nuclear power plants and nuclear medicine. The first use of nuclear energy to produce electricity came in 1951, at an Argonne reactor located in Idaho. The year 1953 marked the first successful tests of a submarine prototype reactor, also developed by Argonne, which led to today's fleet of nuclear-powered submarines.
Nuclear power is also key to space exploration.
It is the only available compact source of reliable, long-term power in space. Today about half of all hospital patients are diagnosed or treated using some form of nuclear medicine. Radioisotopes occur naturally only in limited quantities, but they can be created in large quantities through nuclear reactions. Through research, radioisotopes can now be tailored for particular applications based on an isotope's chemical behavior and the type and energy of its radiation. More than 10 million nuclear imaging procedures are performed each year in the United States.