STRRAP system—A software for hazardous materials risk assessment and safe distances calculation

This work presents a powerful computational tool (Stochastic Toxic Release Risk Assessment Package, STRRAP) useful in risk assessment and emergency planning (safe distance calculation), which allows to handle the stochastic uncertainty of atmospheric parameters, critical for risk calculation when diffusion of hazardous gases or particulate matter occur as a consequence of an emission or accidental release. In fact, the random behaviour of wind intensity, wind direction, atmospheric stability and temperature, given a time horizon, (a season or a complete year), is taken into account considering also the day or night condition.STRRAP can be used for releases or emissions from static sources (for example a stack or a fixed tank in a facility) or from transportation accidents (road, rail, maritime and pipeline transport) involving different scenarios.After a stochastic simulation based on well-known diffusion models (dense and light gases, particulate matter) is carried out, the downwind pollutant concentrations are obtained, in order to compute safe distances and/or individual and societal risks.Some study cases are analyzed to show STRRAP capabilities.