Yep! (What's "emulsion paint"?)

Of course, "duck and cover" wouldn't save anybody from an A-bomb. I think the idea was to save us all from flash-blindness and the broken glass of the shockwave (because of course it was a 60s school, and so mostly glass).

So while I'm not entirely sure Jack would hold on to that level of anti-Soviet paranoia that far into his adult life, he would certainly have grown up with that...