Probabilistic consequence study of residual radiological effects from a hypothetical ten-ton inadvertent nuclear yield. Weapons Safety Program

摘要

In this paper we study the potential radiological consequences of a strategic bomber accident, in which one of the assumed on-board nuclear weapons explodes with an arbitrarily chosen 10-ton nuclear yield. The frequency of such an occurrence is infinitesimal. The safety design features in today s nuclear weapons' systems essentially forbid its occurrence. We have a chosen a military base which has the feature of being a representative combination of urban and rural populations. The assumed ''crash site'' is near the northwest comer of the military base, close to civilian housing located just across the street from the base. A worst case wind would be from the ESE (east south east). This would cause fission debris to be dispersed toward the largest population centers and, thus, would lead to the largest Pu ''collective'' doses (i.e., a dose integrated over time and summed over individuals). Also, if an ESE wind were blowing at accident time, some people in nearby housing could receive lethal gamma-ray doses from fallout before evacuation could occur. It is assumed only one weapon undergoes nuclear yield; the other on-board weapons would HE detonate and the Pu would be aerosolized and lofted. We assume an activity-size distribution and lofting similar to those used to predict fallout measured at NTS. The main thrust of our study is to provide estimates of probabilistic radiological risks to the population local to a strategic bomber crash site. The studied radiological consequences are: cloud-passage doses from Pu inhalation; doses from groundshine due to gamma-producing radionuclides; and areal contamination from Pu and the long-lived fission products Cs-137 and Sr-90.