Oak Ridge National Laboratory was completed, later renamed to "Oak Ridge National Laboratory". The site was chosen for the X-10 Graphite Reactor, used to show that plutonium can be created from enriched uranium. Enrico Fermi and his colleagues developed the world's second self-sustaining nuclear reactor after Fermi's previous experiment, the Chicago Pile-1. The X-10 was the first reactor designed for continuous operation. After the end of World War II the demand for weapons-grade plutonium fell and the reactor and the laboratory's 1000 employees were no longer involved in nuclear weapons. Instead, it was used for scientific research. In 1946 the first medical isotopes were
RA-1 Enrico Fermi used for research and teaching. RA-1 Enrico Fermi RA-1 Enrico Fermi is a research reactor in Argentina and the first nuclear reactor to be built in that country. Construction started April 1957, with first criticality 17 January 1958. It produced the first medical and industrial radioisotopes made in Argentina, and was used to train staff for the first two nuclear power stations there. It is a pool type, with enriched uranium oxide fuel (20% U-235), light water coolant and moderator, and a graphite reflector. It produces 40 kilowatts of thermal energy at full authorised power. It has been modernised on