The BBC also made the excellent "The War Game" in the 1960s - which was withdrawn from being broadcast as "the effect of the film has been judged by the BBC to be too horrifying for the medium of broadcasting. It will, however, be shown to invited audiences...".
https://en.wikipedia.org/wiki/The_War_Game
"The blast wave from a thermonuclear explosion has been likened to an enormous door slamming in the depths of hell"