The concept of utilizing processed fission product wastes as a heat source to produce low-pressure steam in a nuclear waste boiler (NWB) has been analyzed. The conceptual NWB design utilizes solidified wastes from spent fuel reprocessing plants in a natural circulation boiler that is sectionalized to permit continuous operation during refueling. Any one of several proposed commercial solidification processes provides wastes in a containerized form suitable, without modification, to be used in this concept. The NWB is analyzed in terms of its fuel cycle, design, safety, and economic potential. It is competitive with fossil plants of similar capacity in limited applications when substantial quantities of waste are available.