| Original caption: “The first nuclear reactor was erected in 1942 in the West Stands section of Stagg Field at the University of Chicago. On December 2, 1942 a group of scientists achieved the first self-sustaining chain reaction and thereby initiated the controlled release of nuclear energy. The reactor consisted of uranium and uranium oxide lumps spaced in a cubic lattice imbedded in graphite. In 1943 it was dismantled and reassembled at the Palos Park unit of the Argonne National Laboratory where it is still functioning. The sketch is by Melvin A. Miller of the Argonne National Laboratory.” Drawing of the nuclear reactor erected beneath the west stands of the University of Chicago’s Stagg Field. With this 1st nuclear pile, a group of scientists achieved the 1st self-sustaining chain reaction, a controlled release of nuclear energy on December 2, 1942. The reactor consisted of uranium and uranium oxide lumps spaced in a cubic lattice embedded in graphite. In 1943, it was dismantled and reassembled at the Argonne National Laboratory. Melvin A. Miller’s (September 18, 1922 – September 6, 2001) drawing of the world’s 1st atomic reactor in which the 1st self-sustaining chain reaction of splitting atoms and releasing their energy under controlled conditions was achieved. Because of wartime secrecy, no photos were ever made of the completed reactor built by Enrico Fermi and his associates under the University of Chicago’s old football field stands. The reactor was controlled by 3 sets of neutron-absorbing cadmium rods inserted at right angles to the uranium bars encased in the graphite pile. 1 set was automatic and could be controlled from the balcony (upper left) from which Fermi directed the reactor startup. A 2nd set was rope-controlled (the rope would be cut by a scientist armed with an axe) for emergency use. The 3rd control rod was hand-operated (lower left) and the 1 which actually held the reaction in check until withdrawn the proper distance. Primary purpose of the reactor was to test the feasibility of producing the materials for the bombs which brought World War II to a close. Although the reactor produced no power, it led to the development of today’s nuclear power plants. The reactor and the grandstand, under which it was built, have since been dismantled. The location of the reactor is now marked by a bronze plaque which reads “On December 2, 1942, man achieved here the first self-sustaining chain reaction and thereby initiated the controlled release of nuclear energy.” Miller was a draftsman at the University of Chicago Metallurgical Laboratory with the Argonne National Laboratory staff. 2 drawings of the 1st pile were executed by Miller in the fall of 1946. They are based on descriptions given Miller by the men who built the 1st “pile.” | |
| Image Filename | wwii1987.jpg |
| Image Size | 1.66 MB |
| Image Dimensions | 2936 x 2284 |
| Photographer | Mervin A. Miller |
| Photographer Title | Argonne National Laboratory |
| Caption Author | Written or Adapted by Jason McDonald |
| Date Photographed | December 2, 1942 |
| Location | |
| City | Chicago |
| State or Province | Illinois |
| Country | United States |
| Archive | National Archives and Records Administration |
| Record Number | NWDNS-434-RF-62(1) |
| Status | Caption ©2026 MFA Productions LLC Please Do Not Duplicate or Distribute Without Permission; Image in the Public Domain |
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