It's also misleading because it's talking about a bomb 1/10th the size of the Hiroshima nuclear detonation, while today, even just India and Pakistan alone have nuclear capabilities that are a hundred times beyond that. The implications not just from the initial strikes but the infrastructural devastation that would follow are impossible to estimate.
I suspect the kind of civil defence training described on that page would probably help with a small scale terrorist level attack. However, I don't think it would achieve very much in a full scale attack and certainly not the scale of attacks likely during the 1980s and on densely populated areas of Europe.
Where I sit now in Scotland is within range of about 5 different high value Cold War targets - I don't think Duck and Cover would achieve very much.
