§ Mr. David Youngasked the Secretary of State for the Home Department if he will estimate the effect of a one kilotonne nuclear explosion over (a) Manchester and (b) Bolton in terms of the radius of casualties, communications and damage; and if he will make a statement.
§ Mr. MayhewThe broad estimates which follow assume that such a weapon was detonated over Manchester or Bolton at a height calculated to maximise casualties and damage—800 ft—and that the population was given warning of attack.
Within a radius of 1,300 ft from the point on the ground immediately below the explosion —ground zero—most people would be killed; houses would be totally destroyed.
Within a ring from 1,300 to 1,900 ft from ground zero, a high proportion of people would be killed and a high proportion of the remainder seriously injured; houses would be irreparably damaged.
Within a ring from 1,900 to 5,000 ft, a small proportion would be killed and some seriously injured; houses would be severely to moderately damaged.
Within a ring from 5,000 to 10,000 ft, very few people would be killed and a small proportion would suffer injuries, mostly light; houses would be slightly damaged.
Damage to communications would be localised.