Aiken County · Marker 02-36
P Reactor
Road F, Savannah River Site (Not Open to the Public)
Front inscription
One of five production reactors at Savannah River Plant, now Savannah River Site, P Reactor was the site of cutting-edge neutrino research. In 1956, Drs. Clyde Cowan, Jr., and Frederick Reines used P Reactor to confirm for the first time the existence of the free neutrino, a sub-atomic particle of extremely small mass. As a result, Reines won the 1995 Nobel Prize in Physics.
Reverse inscription
P Reactor not only generated prize-winning research but also produced plutonium and tritium for national defense. Built from 1951-1954, it was the second of five reactors here to go on line, running from initial start-up, Feb. 20, 1954, until final shutdown in 1988. During that period, it had the best safety record of any nuclear reactor at the Savannah River Plant.