Nuclear Technology / Volume 161 / Number 2 / February 2008 / Pages 190-202
Technical Note / Miscellaneous
This paper summarizes the results of an independent review of information from the available literature on plutonium release parameters obtained in worldwide studies on accidental fires that might occur in nuclear facilities and generates technically justifiable recommendations on plutonium releases based on this review. This work was limited to the accidental fires in nuclear facilities involving plutonium-contaminated waste materials that can be in either solid or liquid form, as well as involving plutonium metal itself. Releases of plutonium are expressed in terms of the airborne release fraction (ARF), defined as the total fraction of initial material released in the accident, or the airborne release rate, which is the average rate at which ARF is released for the duration of the accident. Respirable fraction of the mass of plutonium dispersed in the air is conditionally assumed to include particles having aerodynamic diameters smaller than 10 m (aerodynamic diameter of a particle is defined as the diameter of a unit density sphere having the same aerodynamic properties as the particle; particles of any shape or density will have the same aerodynamic diameter if their settling velocity is the same). For intense fires in solid waste storage areas or large explosions associated with plutonium metal, up to 50% of the plutonium contamination may be released as respirable aerosol.