Estimation of Effects of Filtration and Ventilation on Worker Inhalation Dose from Aerosols Produced during Nuclear Decommissioning Processes.

Abstract: During the decommissioning of nuclear power plants, radioactive contaminants may be released into the work environment in the form of aerosols, which can expose workers through inhalation, ingestion, and submersion pathways. During dismantlement work, aerosol concentrations may increase due to release from materials. Typical engineering controls to reduce concentrations include air exchange as well as air filtration, which captures aerosols at their source. This work presents a model of radioactive aerosol concentration to estimate the reduction of (a) effluent aerosol concentration into the environment and (b) worker committed effective dose. Controlling the aerosol concentration mitigates the dose that the workers receive. Given that there exists a variety of filtration methods of varying efficiencies and throughputs, a method of estimating dose reduction for a variety of work scenarios is desirable. This work models the time-evolution of radionuclide aerosol concentration as a function of dismantlement work parameters such as work time, aerosol source rate, air exchange, and air filtration. The committed effective dose to a worker as well as the environmental radionuclide aerosol emissions are estimated over a typical 10-h work shift.