Chapter XI : 9 – CALCULATIONAL STUDY OF BANEBERRY*

Baneberry, a 42-TJ (10-kt) nuclear device, was detonated at a depth of 278 m in hole U8d at the Nevada Test Site on 18 December 1970. About 3.5 min after the nuclear explosion, radioactive gases and debris began venting through a shock-induced fissure that had opened earlier near surface ground zero. This report presents results from five computer calculations. The first calculation, BANE 1, provided results in reasonable agreement with all the measurements and observations made on Baneberry. The other four calculations isolate contributions to the shock phenomenology from: a saturated clay-rich tuff layer that surrounded the explosion, a double fault system, a high impedance Paleozoic surface 2.1 cavity radii below the detonation, the free surface and changes in media properties. By varying certain geologic features and material properties their relative effect on ground motion and the residual stress field was determined. Calculational results show how the above features interact with the shock wave to produce: strong compressive reflections, shock wave refraction and focusing, horizontal rebound, asymmetric cavity growth and spalling. These effects are interpreted to explain the observed vent path.