A Multiple Ant Colony Metaheuristic for the Air Refueling Tanker Assignment Problem

The performance of the Nuclear Facility (NFAC) incident module in modeling a nuclear reactor accident is evaluated. Fallout predictions are compared with air concentration measurements of I-131 in Europe over a five-day period. Two categories of source term specifications are used: NFAC-generated source terms based on plant conditions and accident severity, and user-defined source terms based on specifying the release of I-131. The Atmospheric Transport Model Evaluation Study report source term provided the needed detailed release information. The Air Force Combat Climatology Center provided weather data covering Europe during the release\u27s 11-day duration. For the NFAC-generated source terms as few as 20% and as many as 52% of the values are within the intended accuracy, depending on which source term specification was selected. For the user-defined source terms, values ranged 35% to 56% being within the intended accuracy, again depending on which source term specification was used. Performance improved in all cases for monitoring sites closest to Chernobyl, with up to 87% of the values falling within the intended accuracy. This indicates there may be a limit for selecting the spatial domain, making HPAC more useful as a tool for smaller spatial domains, rather than on a continental scale