Argonne nuclear pioneers: Chicago Pile 1 on YouTube (by Argonne National Laboratory) On December 2, 1942, 49 scientists, led by Enrico Fermi, made history when Chicago Pile 1 (CP-1) went critical and produced the world's first self-sustaining, controlled nuclear chain reaction. Click on photo to view a larger image. 8 hours ago December 2, 1942, was the coldest day in Chicago in almost fifty years. CP-2 (Chicago Pile 2 Reactor) In early 1943, Chicago Pile 1 was dismantled at the University of Chicago, moved to the Argonne Forest section of the Palos Hills Forest Preserve, and renamed Chicago Pile 2.

Chicago Weather: Cool Sunday Before A Big Warmup In The WeekSunday will be a sunny and cool day for the Chicago area but still warmer than Saturday. Chicago Pile 2 (CP-2) - pictured in March 1943 - was born in early 1943, when Chicago Pile 1, the world's first nuclear reactor, was dismantled …