Understanding and improving modeling of aerosol evolution in nuclear reactor accidents are important in estimations of the nuclear source term. We explore here the nature of some approximations inherent in the widely used sectional technique for both single- and multicomponent aerosols and the influence these have on results. We also describe our efforts toward improving the fidelity of the sectional technique to the actual physics by coupling the sectional technique with the direct simulation Monte Carlo simulations, and why such coupling has proved difficult.