FIELD: nuclear power engineering; spacecraft power and propulsion plants. SUBSTANCE: power plant has thermionic converter reactor that functions as power supply to transport loads and to continuous power users at reduced power level; thermionic converter reactor core is formed by power-generating fuel assemblies having emitter cladding that accommodates fissionable material and fuel assembly switching system provided with current leads. Reactor core is built of two groups of power-generating fuel assemblies of different service periods; first group incorporates fuel assemblies whose service period is not over operating time of transport loads and service life of second-group fuel assemblies equals to or is longer than total operating time of transport loads and continuous power users; each group of power- generating fuel assemblies is provided with respective switching system and independent current leads. In this way proposed power plant can perform two quite different functions with respect to power capacity and service period. EFFECT: enhanced service period at reduced power level; improved quality of power plant harnessing under ground conditions. 5 cl, 4 dwg
