This invention relates to electric power industry, and can be used in horizontal steam generators for nuclear power plants (NPP) with a water-water energetic reactor (VVER). We claim a steam generator primary circuit coolant header with U-shaped tubes of a horizontal heat-exchange bundle designed as a thick-wall welded vessel with a perforated central cylindrical part designed so as to allow installation and fastening of a U-shaped heat-exchange tube bundle in the same, wherein the tubes are grouped into banks and separated by vertical inter-tubular tunnels, a lower cylindrical part designed so as to allow welded connection with the steam generator vessel connection pipe, and an upper cylindrical part with a conical adapter to the flange connection of the manhole with a lid, wherein primary circuit header outer diameter D.sub.head in the central part is selected based on formula. The technical result of the invention involves assurance of strength of the header wall bridges between holes for fastening of heat-exchange tubes and leaktightness of heat-exchange tube connections with the header assuming that the outer surface of the perforated header part is more efficiently (fully) used for tubing.

A system (1) and method for operating a liquid gas evaporator (3), comprising an evaporator (3), a trough (5) carrying the evaporator (3), a housing (7) which surrounds the evaporator (3) on three sides, at least one detector (9) for sensing liquid gas arranged in the trough (5), a line (11) for the distribution of vapor D on the fourth, non-housed side of the evaporator (3) arranged at the margin of the trough (5) which is not closed off by the housing (7), a feed (13), connected to the line (11), and a regulating valve (15) provided on the feed (13) and connected to the detector (9) and at least one shut-off valve (17).

A compact pressurized water nuclear reactor having connected to the reactor pressure vessel a plurality of pressure vessels connected by nozzles, and connected by curved horizontal pressure vessel heads by having their central axis horizontal, with reduced stress and simple single connection between the respective nozzle of the reactor pressure vessel with the respective nozzle of each curved horizontal pressure vessel heads, all with the same internal and external design pressure.

A method is provided to vaporize a working fluid using a heat sourcing fluid. A first portion of the heat sourcing fluid passes through the first section, in counter-flow with the working fluid. A second portion of the heat sourcing fluid passes through the second section, in co-flow with the working fluid. Both the first and second portions pass through the third section, in overall counter-flow with the working fluid. The working fluid passes sequentially through the third section, the first section, and the second section. The method may be used in a Rankine cycle for waste heat recovery or in a refrigerant cycle.

A nuclear steam supply system having a shutdown system for removing residual decay heat generated by a nuclear fuel core. The steam supply system may utilize gravity-driven primary coolant circulation through hydraulic-ally interconnected reactor and steam generating vessels forming the steam supply system. The shutdown system may comprise primary and secondary coolant systems. The primary coolant cooling system may include a jet pump comprising an injection nozzle disposed inside the steam generating vessel A portion of the circulating primary coolant is extracted, pressurized and returned to the steam generating vessel to induce coolant circulation under reactor shutdown conditions. The extracted primary coolant may further be cooled before return to the steam generating vessel in some operating modes. The secondary coolant cooling system includes a pumped and cooled flow circuit operating to circulate and cool the secondary coolant, which in tun extracts heat from and cools the primary coolant.

A nuclear steam supply system having a start-up sub-system for heating a primary coolant. In one embodiment, the invention can be a nuclear steam supply system comprising: a reactor vessel having an internal cavity, a reactor core comprising nuclear fuel disposed within the internal cavity; a steam generating vessel fluidly coupled to the reactor vessel; a primary coolant loop formed within the reactor vessel and the steam generating vessel, a primary coolant in the primary coolant loop; and a start-up sub-system fluidly coupled to the primary coolant loop, the start-up sub-system configured to: (1) receive a portion of the primary coolant from the primary coolant loop; (2) heat the portion of the primary coolant to form a heated portion of the primary coolant; and (3) inject the heated portion of the primary coolant into the primary coolant loop.

A method for generating process steam using condensate recycled in the form of feed water is described and illustrated. In order to be able to achieve a higher efficiency with the method, it is proposed that the process steam is delivered to a consumer device (V) to form a condensate by at least partial condensation of the process steam, that the condensate from the consumer device (V) is fed to a feed water treatment for treatment, that feed water from the feed water treatment is separated into a steam phase and a liquid phase in a flash tank, that the liquid phase of the feed water is evaporated in an evaporator to form a raw steam, and that the steam phase of the feed water and the raw steam are compressed in at least one compressor to form process steam.

A method for generating process steam using condensate recycled in the form of feed water is described and illustrated. In order to be able to achieve a higher efficiency with the method, it is proposed that the process steam is delivered to a consumer device (V) to form a condensate by at least partial condensation of the process steam, that the condensate from the consumer device (V) is fed to a feed water treatment for treatment, that feed water from the feed water treatment is separated into a steam phase and a liquid phase in a flash tank, that the liquid phase of the feed water is evaporated in an evaporator to form a raw steam, and that the steam phase of the feed water and the raw steam are compressed in at least one compressor to form process steam.

A sodium-chlorine generator generates electricity. Chlorine gas is combined with sodium metal in a boiler. The reaction is exothermic and generates sodium chloride as a biproduct. The heat can be used to boil water to generate steam. The steam generated can be used to turn a turbine, which produces electricity. The reactor can use a heat exchanger to connect a boiler that is separated from reactor. The rate and output of the reaction can be changed by pressurizing the chlorine gas with the reactor and by preheating the sodium before the reaction. The sodium chloride can be recycled to generate sodium metal and chlorine gas for a subsequent use.

A sodium-chlorine generator generates electricity. Chlorine gas is combined with sodium metal in a boiler. The reaction is exothermic and generates sodium chloride as a biproduct. The heat can be used to boil water to generate steam. The steam generated can be used to turn a turbine, which produces electricity. The reactor can use a heat exchanger to connect a boiler that is separated from reactor. The rate and output of the reaction can be changed by pressurizing the chlorine gas with the reactor and by preheating the sodium before the reaction. The sodium chloride can be recycled to generate sodium metal and chlorine gas for a subsequent use.