Source term is an important issue in safety assessment of nuclear power plants. Therefore, modeling of particulate concentration in reactor coolant systems during normal operation and hypothesized accidents is of continuing interest. We report here on exploration of a numerical solution of the Reeks-Hall equation with the use of the fractional resuspension rate in its original integral form. The numerical results for particulate concentration are compared with those obtained from the exact expression given by Williams and experimental data provided by Wells et al. The numerical results agree very well with exact results and also agree well with the data of Wells et al. Applications of the numerical method to problems with a time-dependent resuspension rate (for which exact solutions are not available) are explored, and some typical results are reported. The numerical method will be useful for verifying approximate techniques that are used for aerosol modeling in nuclear source term computer programs.