I remember the nuns just used to let us pray at our desks. More rational than the duck and cover.
Out nuclear drills in Kansas doubled as tornado drills. Out in the halls, on your knees, head against the wall. That’s where survivors were usually found. Prayer optional.
When Duck and Cover first appeared it actually made sense. Delivery systems were very limited. The likelihood of more than one bomb on a city was limited. The bombs themselves were small by later standards, fission not fusion. A 50kt exploding 5K ft over Times Square would break windows in eastern Queens. The mocking of Duck and Cover is valid as delivery systems and explosive power grew exponentially, but when I was doing it in the early grades it may well have worked.