Children of the Dust by Louise Lawrence 1985

See the New Year in with a bang as humainity goes out with a wimper in this eighties YA book.

Everyone thought, when the school bell rang, that it was just another fire alarm but the first bombs had already fallen.
Sarah and her family have to stay sealed up in the kitchen for days on end, dreading radioactive fall-out and a slow, torturous death, which may be preferable to surviving in a grey, dead world, choked by dust.

But then, from out of the dust and destruction, children are born with strange mutations is this new life a new future?