The efficacy of uranium and thorium waste in a blanket of a thermonuclear plant, whose tasks are breeding of tritium as fuel for a thermonuclear plant and the production of fuel for thermal reactors, are compared: 239Pu on loading raw uranium and 233U on loading thorium as well as power generation. Different blanket arrangements are considered and investigated. It is shown that the tasks can be fulfilled only within the framework of a lithium-uranium blanket, whose characteristics in the considered variants are significantly higher compared to lithium-thorium.