Harold Geisler takes Plum Brook reactor critical
Harold Geisler takes Plum Brook reactor critical for the first time on the evening of 14 June 1961. NASA's Plum Brook facilities are located near the Glenn Research Center in Ohio. This first self-sustaining chain reaction was conducted at very low power. It wasn't until the following April that the reactor reached its full potential of sixty megawatts. By July 1963, the reactor had completed its first experimental cycle while critical.
Image number: C-1961-56899
Date: June 14, 1961