1940-49 || 1950-59 || 1960-69 || 1970-79 || 1980-89 || 1990-99 || 2000-present

Argonne Highlights: 1942-1949

1942

December 2 -- Enrico Fermi's team produces the world's first sustained nuclear chain reaction.

1943

March 20 -- Chicago Pile 2 achieves criticality. It was CP-1, Fermi's first reactor, dismantled and reassembled at the Argonne Forest site in the Cook Country Forest Preserve.

1944

May 15 -- Walter Zinn starts Chicago Pile 3, the world's first heavy-water-moderated nuclear reactor, at Site A.

1946

April 19 -- Argonne's birthday: The University of Chicago accepts a letter contract to operate an Argonne National Laboratory, as yet unnamed and not officially in existence.

July 1 -- The name of the Manhattan Engineering District's Metallurgical Laboratory is officially changed to Argonne National Laboratory, with Walter Zinn as director.

August 1 -- Pres. Harry Truman signs the Atomic Energy Act.

October 7 -- The University of Chicago Board of Governors discusses for the first time the organization of Argonne, its scientific programs, and cooperation between participating institutions and the laboratory.

October 31 -- University of Chicago signs a contract to operate Argonne.

December 31 -- President Harry S Truman signs an executive order officially transferring to civilian control all activities of the Manhattan Engineering District, effective at midnight.

1947

January 1 -- The Atomic Energy Commission (AEC) assumes jurisdiction and sponsorship for Argonne with the University of Chicago operating the laboratory.

January 23 -- The Atomic Energy Commission (AEC) authorizes Argonne's purchase of 3,700 acres in DuPage County.

January 29 -- General Leslie Groves approves Argonne's purchase of about 3,700 acres of land in DuPage County to become Argonne's new site.

January 31 -- Argonne begins design of a thermal, water-cooled submarine reactor.

November 19 -- The AEC authorizes Argonne to design and build a liquid-metal-cooled, fast-neutron reactor. Alternately referred to as "Chicago Pile 4" and "Zinn's Infernal Pile," it becomes EBR-I.

December 31 -- The AEC gives Argonne approval to develop nuclear submarine power plant.

1948

January 1 -- The AEC designates Argonne its principal reactor-development center.

April 22 -- Walter Zinn proposes that the AEC establish a national reactor proving ground. His proposal results in the establishment of the National Reactor Testing Station, the forerunner of today's Idaho National Laboratory.

August 25 -- Argonne and Westinghouse announce a program of scientific and technical cooperation to commercialize nuclear power.

September 9 -- First Argonne Picnic held.

December 3 -- Walter Zinn establishes the Naval Reactor Division.

1949

February 8 -- A bottle containing 31 grams of enriched uranium, about one-sixtieth the amount needed for a nuclear weapon, is discovered missing from an Argonne vault. Investigation finds that all but about seven grams had been shipped to Oak Ridge National Laboratory. The remaining seven grams are found in a trash container in Argonne's landfill. Subsequent congressional investigation leads to a tightening of Argonne's record-keeping procedures for "sensitive materials."

February 18 -- The AEC approves the Idaho site for construction of the National Reactor Testing Station.

March 21 -- Walter Zinn determines that a water-cooled reactor is the surest approach to a successful naval reactor.

March 28 -- Materials Testing Reactor named top priority in nation's reactor development program.

October 5 -- The Argonne Credit Union is chartered as an Illinois corporation as the result of a petition by 11 Argonne employees wishing to deposit a total of $55.

1940-49 || 1950-59 || 1960-69 || 1970-79 || 1980-89 || 1990-99 || 2000-present