Characterization of aerosols from industrial fabrication of mixed-oxide nuclear reactor fuels

Information on the characteristics of aerosols in three industrial facilities during fabrication of uranium and plutonium mixed-oxide reactor fuels is summarized. Aerosol characterization included measurements of air concentrations particle size distributions, particle morphology, aerosol electrostatic charge characteristics and in vitro dissolution. These were the physicochemical properties considered most relevant to evaluating the consequences of potential accidents wherein aerosols might be released from their normal containment and inhaled by workers. Alpha radioactivity concentrations in air ranged about 1-15,000 nCi/l, depending on the fabrication step and facility. Particle size distributions were approximately log-normal, and activity median aerodynamic diameter (AMAD) ranged 1.6-3.5 μm, with a geometric standard deviation of about 1.6. Electron microscopy indicated that particles were irregularly shaped agglomerates. In vitro dissolution half-times were on the order of years, with some dependence on aerosol size, temperature history and fabrication step. No unique potential exposure conditions were found in any step of the fabrication processes