NBC Hazard Prediction Model Capability Analysis

This report provides a limited operational assessment of the DoD standard NBC hazard prediction models, focusing on the VLSTRACK and HPAC models. The motivation for this effort was a concern about variance in hazard predictions produced by operational users. The study team conducted a survey of users at the CINCs and many of the major commands. There was little evidence of standardization or institutionalization of hazard prediction in general or the use of models such as HPAC or VLSTRACK in particular. There were significant differences in focus, opportunities for model use, and skills at the various levels of command that are likely to have a considerable impact on the employment of the models. In comparing the models, even in simple scenarios, the models sometimes produced very different predictions. In several cases, there were significant differences in source term and toxicological assumptions. Accounting for these differences led to outputs that were more similar in some, but not all, cases. A significant portion of the variation appears to be due to fundamental differences in the modeling of transport and dispersion.