P Reactor
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.
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.
Where it stands. Road F, Savannah River Site (Not Open to the Public), Savannah River Site