The results of an investigation of the beam dynamics in a high-power proton accelerator-driver intended for operation as part of a subcritical electronuclear facility are presented. The initial normally conducting part of the accelerator at current 10 mA with current-passage ratio >95% has been developed. A channel with current-passage ratio 100% has been developed for the superconducting part of the accelerator. Modeling of the accelerating cavities for all velocity ranges has been done. High electrodynamic performance has been attained as a result of optimization.