Abstract: Aspects of the invention generally provide a heat engine system and a method for activating a turbopump within the heat engine system during a start-up process. The heat engine system utilizes a working fluid circulated within a working fluid circuit for capturing thermal energy. In one exemplary aspect, a start-up process for a turbopump in the heat engine system is provided such that the turbopump achieves self-sustained operation in a supercritical Rankine cycle. Bypass and check valves of a start pump and the turbopump, a drive turbine throttle valve, and other valves, lines, or pumps within the working fluid circuit are controlled during the turbopump start-up process. A process control system may utilize advanced control techniques of the control sequence to provide a successful start-up process of the turbopump without over pressurizing the working fluid circuit or damaging the turbopump via low bearing pressure.

Abstract: A steam generator for a nuclear reactor comprises plenums proximate with a first plane, wherein the first plane intersects a bottom portion of a riser column of a reactor vessel. The steam generator may further comprise plenums proximate with a second plane, approximately parallel with the first plane, wherein the second plane intersects a top portion of the riser column of the reactor vessel. The steam generator may further include a plurality of steam generator tubes that convey coolant from a plenum located proximate with the first plane to one of the plenums proximate with the second plane.

Abstract: A nuclear reactor in which a primary coolant is contained, the primary coolant moves upwardly from the core by an operation thereof. An annular steam generator is arranged in an upper side of the core into which the upwardly moving primary coolant flows and transfers heat in the primary coolant into water therein to generate a steam. A passage structure defines a coolant passage for the primary coolant to an outside of the core. The heat-transferred primary coolant in the annular steam generator flows downwardly in the coolant passage so as to flow into the core, thereby moving upwardly. A reactor vessel is arranged to surround the coolant passage so as to contain the core, the annular steam generator and the passage means therein.

Abstract: A pressure vessel of a reactor has a flow space between the reactor core and a separation device for separating water from water steam. The cross-section area of the flow section of the space expands upstream of the separation device. This makes it possible to pre-separate a water-water steam mixture coming from the reactor core. Due to the pre-separation, only the central area is provided with a cyclone device, and only drying equipment is disposed near the cyclone device. The novel approach makes it possible to reduce the height of the pressure vessel of a reactor.

Abstract: The disclosed power plant can attain an extremely high thermal efficiency, as compared with that of the conventional power plant. The power plant comprises a steam system and a mixed medium system. The steam system comprises a heat source (1) for generating steam; a steam turbine (3) driven by the steam generated by the heat source; a steam condenser (81) for forming condensed water by condensing exhaust of the steam turbine; and a condensed water feeding pump (9) for feeding the water condensed by the steam condenser to the heat source.

Abstract: A natural circulation type boiling light-water reactor comprises a pressure vessel, a reactor core disposed within said pressure vessel to heat light water so as to generate main steam, a steam outlet provided in a wall of said pressure vessel for drawing out the main steam therethrough to supply the same to a turbine system, and a steam path along which the main steam flows from the reactor core to the steam outlet. The reactor further comprises a steam guide for prolonging the steam path and/or a radially increased chimney for reducing the velocity of the main steam flowing through the steam path. These causes radioactive isotope .sup.16 N contained in the main steam to flow within the pressure vessel for a time period exceeding its own half-life, so that the inventory of .sup.16 N in the main steam directed towards the turbine system is reduced remarkably. In consequence, shield structures for piping and turbine systems can be reduced in size and weight.

Abstract: A steam separating system for boiling water nuclear reactors comprising a combination of mechanical steam separators with steam collecting and transferring units.

Abstract: In moisture separator reheaters of a nuclear power plant, a control valve is mounted in a steam vent line of the plant to control the flow rate of vent steam in conformity with the load applied to the plant, to thereby avoid the occurrence of any instable flow phenomenon in the entire range of loads applied to the plant.

Abstract: The present invention is related to nuclear reactors. More specifically, this invention is directed to a means for venting pressurized water reactors.

Abstract: A main steam line apparatus of a boiling water nuclear reactor plant including piping for introducing a steam produced in a pressure vessel into a turbine, a main steam valve for rapidly stopping the steam being supplied to the turbine through the piping, and a header. The header is located in the piping between the pressure vessel and the main steam valve. The header causes the pressure wave which occurs when the main steam valve is rapidly closed to be attenuated and an increase in pressure vessel pressure to be suppressed.