News Media Resources: DTRA Fact Sheets - Hazard Prediction and Assessment Capability (HPAC)
Hazard Prediction and Assessment Capability
The Hazard Prediction and Assessment Capability (HPAC) automated software system provides the means to accurately predict the effects of hazardous material released into the atmosphere and its impact on civilian and military
populations. The system uses integrated source terms, high-resolution weather forecasts and atmospheric transport & dispersion analyses to model hazard areas produced by military or terrorist incidents and industrial accidents.
About the HPAC system
Operation Desert Storm illustrated the need for an automated hazard prediction tool. During that campaign, predictions of the collateral effects of potential weapons-of-mass-destruction use were inefficient and untimely. Predictions were conducted by sending requests for analysis from the theater of operations to the Defense Nuclear Agency (a predecessor organization to the Defense Threat Reduction Agency - DTRA) for technical analysis. Analytical products were then sent back to the theatre. This experience prompted the effort to make hazard prediction and collateral effects tools available to the theatre of operations. DTRA's background of more than 50 years of research blast effects and analysis provided a strong platform to accomplish this mission.
HPAC features
The Hazard Prediction and Assessment Capability system is a forward-deployable, counterproliferation-counterforce collateral-effects assessment tool available by license for government, government-related or academic use. It provides the means to accurately predict the effects of hazardous material releases into the atmosphere and its impact on civilian and military populations. It models nuclear, biological, chemical, radiological and high explosive collateral effects resulting from conventional weapon strikes against enemy weapons of mass destruction production and storage facilities. The HPAC system also predicts downwind hazard areas resulting from a nuclear weapon strike or reactor accident and has the capability to model nuclear, chemical and biological weapon strikes or accidental releases.
Relevant real-world hazard prediction requires timely and accurate weather data in the area of concern. The HPAC system allows the user easy access to forecast weather and real-time weather (observations) data by using a variety of DTRA supported Meteorological Data Server systems. The HPAC system also has embedded climatology or historical weather data for use when planning incidents beyond the normal time associated with credible weather forecast data. One-kilometer terrain data and supporting wind-flow models calculate the local winds field in the area of concern. Other weather sources are also available upon request to DTRA.
The HPAC system can also help answer the question, “How good is the prediction?” by providing probabilistic calculations. The h azard area feature estimate s the weather uncertainty and turbulence effects on possible plume trajectories and calculates the areas of hazard impact and the degree of confidence of the prediction.
Although the HPAC system is primarily a personal computer-based model, it is also available on a UNIX platform.
Recent enhancements to the HPAC 4.0.4 series:
Map-based graphical user interface
Client-server distributed architecture
Urban modeling capability
Industrial facility model and industrial transportation model
Quicker access and expanded network to weather services
The Hazard Prediction and Assessment Capability (HPAC) automated software system provides the means to accurately predict the effects of hazardous material released into the atmosphere and its impact on civilian and military 