Cratering and radioactivity results from a nuclear cratering detonation in basalt

Abstract

A summary of the cratering and radioactivity release data from project Danny Boy, a recent 0.42-kt nuclear cratering detonation in basalt, is presented. The detonation was at a depth of 33.5 m and produced a crater about 32.5 m in radius and 19 m deep. Comparison of the crater dimensions with past cratering results in basalt shows that the Danny Boy crater agrees with these data when W1/3.4 scaling is used and an equivalence between chemical and nuclear explosives is assumed. Integration of the fallout pattern shows that about 4 per cent of the radioactivity produced in the explosion escaped from the crater and appeared as fallout. The disposition of the radioactivity in the crater area and in the fallout is given. On the basis of the above results, it is concluded that both the cratering results and the radioactivity-release results are well within predictions made before the event.