Based on Strategic Air Command's Deep Underground Support Center (DUSC) planned near the Cheyenne Mountain Complex nuclear bunker,[1]: 363 the DUCC plan was recommended to President John F. Kennedy for fiscal year 1965 funding shortly before his assassination,[1]: 318, 364 but the underground DUCC, SAC's DUSC, and NORAD's Super Combat Centers were never built.
His view of nuclear war was brought home to me by his reaction at the final meeting in 1965 on the military budget to an item listed as DUCCS.
In response to his question as to what this was, he was told it stood for Deep Underground Command and Control Site, a facility that would be located several thousand feet underground, between the White House and the Pentagon, designed to survive a ground burst of a 20-megaton bomb and sustain the president and key advisers for several months until it would be safe to exit through tunnels emerging many miles outside Washington.
After a brief puzzled expression, Johnson let loose with a string of Johnsonian expletives making clear he thought this was the stupidest idea he had ever heard and that he had no intention of hiding in an expensive hole while the rest of Washington and probably the United States were burned to a crisp.
[2] Other contemporary underground installations did see upgrades, such as the 1953 Site R which was "hardened further to about 140 psi blast resistance by 1963,"[1]: 315 or completion, such as the NORAD's Canadian bunker in 1963, and NORAD's Combat Operations Center & Space Defense Center in the Cheyenne Mountain bunker became operational in 1966.