31 1963 Experimental Breeder Reactor No. II EBR-II achieved its first criticality in November 1963, representing the next evolutionary step in the march toward commercial-sized breeder reactors. Located inside a landmark containment shell at the newly established Argonne-West area, EBR-II was 20 times larger than EBR-I and investigated the feasibility of on-site fuel reprocessing adjacent to a fast-neutron breeder reactor. In August 1964, it first produced electricity, generating 20 megawatts of electrical power.The reactor supplied all the Argonne-West power, with excess for the NRTS grid, until EBR-II was shut down in 1994.