A numerical study of the effect produced on the performance of a tokamak reactor by injecting deuterium-tritium pellets is described. The research was carried out with a one-dimensional space-time plasma physics model describing the energy and particle balance in a tokamak reactor plasma subject to the combined effects of various transport processes, including anomalous processes. The energy parameters of the reactor are defined as functions of fuel consumption and the velocity and frequency of fuel pellet injection. © 1979 IOP Publishing Ltd.