Probabilistic Characterization of Nuclear-Blast Loads

Abstract

With increasing stockpiles of nuclear warheads, it has become essential to fortify critical infrastructure against nuclear blast. Therefore, a reliable estimation of nuclear-blast load is crucial for design of such hardened facilities. Several previous studies analyzed nonnuclear explosion scenarios without specific attention to nuclear explosions. In this paper, a standard nuclear-blast model from the literature is compared with the declassified nuclear test data, and it is observed that the standard model reasonably captures the mean trend of the decay portion of the air-overpressure history. This study accounts for the uncertainties associated with (1) the standard model, (2) occurrence of an explosion, and (3) inherent variability of nuclear-attack parameters (range, yield, and height of burst) by (1) comparing the field data with the model estimates, (2) developing a probabilistic threat scenario model, and (3) assigning appropriate probability distributions to the nuclear-attack parameters, respectively. The incorporation of these uncertainties into the standard model leads to the probabilistic characterization of nuclear-blast loads. For direct use in design, two simple equations are proposed for peak overpressure and positive phase duration in terms of probability of exceedance, and an equation is proposed that represents a normalized air-overpressure history.