Airborne radioactive source terms in compartment fires

Pacific Northwest Laboratory (PNL) has developed source terms for the releases of radioactive aerosols during fires. The work was performed in a joint effort with Los Alamos National Laboratpry and Union Carbide Corporation to provide an accident analysis handbook on nuclear fuel cycle facilities for the US Nuclear Regulatory Commission. Source terms models were developed for the following release mechanisms: burning of contaminated combustible solids; burning of contaminated combustible liquids; heating of noncombustible contaminated surfaces; heating of unpressurized radioactive liquids; pressurized releases of radioactive powders; pressurized releases of radioactive liquids; spills of radioactive powders; and spills of radioactive liquids. Using an idealized burning model and incorporating compartment effects (boundary effects) with the above radioactive source models into a computer code (FIRIN1), PNL has performed a scoping analysis on the magnitude of airborne releases of radioactivity for a number of fuel cycle facility fires. The types of fires considered were general MOX facility fires involving glove boxes, stored combustible waste fires, and solvent extraction fires in waste reprocessing facilities. Several fire scenarios were developed for each fire type based upon the available ranges of both combustible and radioactive loadings in the compartment, as well as the sources of ignition and ventilation rates