The Argonne National Laboratory is an American centre for research in nuclear and high-energy physics, located at Argonne, Illinois., near Chicago. It was founded in 1946 and is operated by the University of Chicago and Argonne Universities Association for the US Department of Energy. The staff of about 5000 conduct research into the peaceful uses of nuclear energy and related environmental problems. The first experimental boiling water reactor was constructed here in 1956. Current facilities include breeder reactors and an intense pulsed neutron source. Its protonaccelerator, called the zero-gradient synchrotron, or ZGS, was shut down in 1970. Research Argonne National Laboratory