A thermal control system for a reactor pressure vessel comprises a plate having a substantially circular shape that is attached to a wall of the reactor pressure vessel. The plate divides the reactor pressure vessel into an upper reactor pressure vessel region and a lower reactor pressure vessel region. Additionally, the plate is configured to provide a thermal barrier between a pressurized volume located within the upper reactor pressure vessel region and primary coolant located within the lower reactor pressure vessel region. One or more plenums provide a passageway for a plurality of heat transfer tubes to pass through the wall of the reactor pressure vessel. The plurality of heat transfer tubes are connected to the plate.

An organic Rankine cycle machine and a supplementary reservoir of water, distinct from the pool, the energy stored in the pool being the hot source for the organic Rankine cycle evaporator, the supplementary reservoir of water feeding the organic Rankine cycle condenser directly via a dedicated pump to constitute the cold source of the organic Rankine cycle condenser.

Claimed embodiments of the integral nuclear reactor relate to nuclear technology and can be used in reactors with different types of heat transfer fluids with a high boiling point, such as, for example, liquid metals, molten salts, etc. Design features of the invention embodiments claimed which have a coil heat exchanger sectioned along the secondary heat carrier circuit provides for an improvement in technical and economic features due to a decrease in metal consumption of the reactor; efficient use of the internal volume of the reactor; improved safety in case of the heat exchanger tube leaks; enabling the removal of residual heat during the time after removal of the protective plug before fuel discharge operations.

A multipurpose small modular fluoride-salt-cooled high-temperature reactor energy system includes: a reactor body system, a passive residual heat removal system, a compact supercritical carbon dioxide Brayton cycle system, a secondary loop system, and a comprehensive utilization supercritical carbon dioxide Brayton cycle system. Nuclear reactor adopts helical cruciform fuel and graphite matrix material filled with TRISO element, which can improve heat transfer performance and inherent safety. Thermal efficiency of the compact supercritical carbon dioxide Brayton cycle system is above 48%, which can be used in places with limited space. Thermal efficiency of the comprehensive utilization supercritical carbon dioxide Brayton cycle system is above 54%, which can be applied to places with abundant resources. The present invention not only realizes efficient and compact utilization of energy, but also meets the needs of multiple purposes, integrated production, storage and conversion of energy.

The present invention provides an integrated passive reactor system comprising a pressure vessel, a containment vessel arranged outside the pressure vessel and a reactor core arranged inside the pressure vessel, wherein the primary loop operates in full natural circulation. The integrated reactor system is also provided with a secondary side passive residual heat removal system comprising primary loop heat exchanger(s) arranged inside the pressure vessel and passive residual heat removal heat exchanger(s) arranged outside the containment vessel, wherein the primary loop heat exchanger(s) is/are arranged above the reactor core, the passive residual heat removal heat exchanger(s) is/are arranged inside water tank(s) which is/are fixed outside the containment vessel, and the primary heat exchanger(s) and the passive residual heat removal heat exchanger(s) are connected by heat exchanger inlet pipelines and heat exchanger outlet pipelines. By adopting passive safety technology and passive residual heat removal system, and with the help of top double-layer structure of pressure vessel and break isolation measures, the integrated reactor system according to the present invention can reduce the loss of coolant to the greatest extent, thus meeting the requirements for mitigating design basis accidents, ensuring reactor safety and simplifying the design of the system.

An aft plenum assembly for use with a nuclear thermal reactor including a pressure vessel and a nozzle assembly having a top plenum plate disposed within the pressure vessel, the top plenum plate defining a first plurality of fuel flow apertures, a bottom plenum plate disposed within the pressure vessel, the bottom plenum plate being parallel to the top plenum plate thereby defining a plenum space therebetween, the bottom plenum plate defining a second plurality of fuel flow apertures, and a plurality of tubular connections extending between the first plurality of fuel flow apertures of the top plenum plate and the second plurality of fuel flow apertures of the bottom plenum plate, wherein the aft plenum assembly is disposed between the pressure vessel and the nozzle assembly.

The present relates to the integration of the primary functional elements of graphite moderator and reactor vessel and/or primary heat exchangers and/or control rods into an integral molten salt nuclear reactor (IMSR). Once the design life of the IMSR is reached, for example, in the range of 3 to 10 years, it is disconnected, removed and replaced as a unit. The spent IMSR functions as the medium or long term storage of the radioactive graphite and/or heat exchangers and/or control rods and/or fuel salt contained in the vessel of the IMSR. The present also relates to a nuclear reactor that has a buffer salt surrounding the nuclear vessel. During normal operation of the nuclear reactor, the nuclear reactor operates at a temperature that is lower than the melting point of the buffer salt and the buffer salt acts as a thermal insulator. Upon loss of external cooling, the temperature of the nuclear reactor increases and melts the buffer salt, which can then transfer heat from the nuclear core to a cooled containment vessel.

Methods of fabricating structures, such as parts for use in nuclear power generation systems, are described herein. A representative method of fabricating a part for a nuclear reactor system includes coating a plurality of particles of a powder of a first material with a second material, and then pressing and/or heating the coated powder into a monolithic structure. The second material can be substantially solidly insoluble with the first material such that, after pressing and/or heating, the particles of the first material define grains of the monolithic structure and the second material substantially encapsulates the grains in the monolithic structure. The first material can be susceptible to corrosion by a select process, and the second material can be resistant to corrosion by the select process such that the bulk first material of the monolithic structure is resistant to corrosion by the select process.

Steam generator systems including tubesheet assemblies, such as for use in nuclear reactor systems, and associated devices and methods are described herein. A representative steam generator system can be installed in a nuclear reactor vessel positioned to house a primary coolant. The steam generator system can include a tubesheet assembly defining a plenum and comprising a tubesheet and a flexible connection portion coupling the tubesheet to the reactor vessel. The tubesheet can include a plurality of perforations fluidly coupled to the plenum. The steam generator system can further comprise a plurality of heat transfer tubes fluidly coupled to the perforations and configured to receive a flow of a secondary coolant. The connection portion can be more flexible than the tubesheet and the reactor vessel to reduce stresses on the tubesheet and the connections (e.g., tube-to-tubesheet (TTS) welds) between the tubes and the tubesheet during operation of the nuclear reactor system.

The present relates to the integration of the primary functional elements of graphite moderator and reactor vessel and/or primary heat exchangers and/or control rods into an integral molten salt nuclear reactor (IMSR). Once the design life of the IMSR is reached, for example, in the range of 3 to 10 years, it is disconnected, removed and replaced as a unit. The spent IMSR functions as the medium or long term storage of the radioactive graphite and/or heat exchangers and/or control rods and/or fuel salt contained in the vessel of the IMSR. The present also relates to a nuclear reactor that has a buffer salt surrounding the nuclear vessel. During normal operation of the nuclear reactor, the nuclear reactor operates at a temperature that is lower than the melting point of the buffer salt and the buffer salt acts as a thermal insulator. Upon loss of external cooling, the temperature of the nuclear reactor increases and melts the buffer salt, which can then transfer heat from the nuclear core to a cooled containment vessel.