A third of these are warheads — dubbed W76 — which, since 1978, have been deployed atop submarine - based ballistic missiles or stored in what is known as the Enduring Nuclear Stockpile, according to Hans Kristensen, director of the Nuclear Information Project at the Washington, D.C. - based Federation of American Scientists (FAS), an organization founded by the creators of the original nuclear weapon in 1945 that has been monitoring the nation's
nuclear arsenal ever since.