Abstract: The invention relates to nuclear power engineering and is intended for using in power plants with a reactor with a heavy liquid metal coolant (HLMC) based on lead or on lead-bismuth alloys. The invention makes it possible to increase the radiation protection efficiency for the in-vessel equipment of a nuclear reactor, to increase the heat storage capacity of the primary circuit, to reduce the nuclear reactor weight, and to improve its strength characteristics. In the in-vessel space of a nuclear reactor, which is not occupied by the necessary equipment, containers filled with a material that reflects or absorbs neutrons, with a heat capacity greater than that of the coolant, are installed with gaps ensuring the coolant flow, while the containers are placed in such a way that the resulting gaps form channels with a turbulent coolant flow to cool these containers at a flow rate corresponding to the nominal power output level of the nuclear reactor.

Abstract: Embodiments of the disclosure may include a reactor vessel with a lower chamber, a core, a hot chamber, an upper chamber, and heat exchangers. In some embodiments, the hot chamber may be located above the core and may include a substantially cylindrical body. In some embodiments, the hot chamber body may include an inner shell and an additional shell installed with a gap on the outside and being concentric with the inner shell of the hot chamber, forming at least one cooling channel. In some embodiments, the connecting pipe may include an inner shell and an additional shell installed with a gap on the outside, being concentric with the inner shell of the connecting pipe and forming at least one cooling channel of the connecting pipe, where the cooling channel of the hot chamber and the connecting pipe are in communication with the outlet of the heat exchangers.