I remember films like this. Of course, being a little younger than this film, the scare was more hydrogen bombs. My grade school years were in the shadow of the Cuban missile crisis. By that time, thermonuclear weapons made the idea of Duck and Cover kind of silly. Still, I remember this film. The school must have gotten a deal on the print. I remember joking with the other kids that it wasn’t Duck and Cover anymore. The joke was “Put your head between your knees and kiss your a** goodbye”.
It became really evident by 1965 or so, that a nuclear war wasn’t survivable. Now, about 45% of the nuclear energy the United States uses comes from decommissioned nuclear weapons we buy from countries that used to be part of the former Soviet Union. They still have 2800 nukes pointed at us. We still have 2200 nukes pointed at them.