A main heat and waste heat integrated thermal exchanger for a small nuclear reactor has a first coolant zone for a first main heat loop, a second coolant zone for a second main heat loop and a third coolant zone for a waste heat removal loop. The first coolant for the first main heat loop passes through the first coolant inlet, and then reaches the orifice plate, and finally flows out from the first coolant outlet. The second coolant for the second main heat loop passes through the second coolant inlet, and then reaches the lower tube sheet, and finally flows out from the second coolant outlet. The third coolant for the waste heat removal loop enters the entrance sleeve through the third coolant inlet, and then enters multiple tubes of the tube bundle, and then enters the exit sleeve, and finally flows out from the third coolant outlet.

A main heat and waste heat integrated thermal exchanger for a small nuclear reactor has a first coolant zone for a first main heat loop, a second coolant zone for a second main heat loop and a third coolant zone for a waste heat removal loop. The first coolant for the first main heat loop passes through the first coolant inlet, and then reaches the orifice plate, and finally flows out from the first coolant outlet. The second coolant for the second main heat loop passes through the second coolant inlet, and then reaches the lower tube sheet, and finally flows out from the second coolant outlet. The third coolant for the waste heat removal loop enters the entrance sleeve through the third coolant inlet, and then enters multiple tubes of the tube bundle, and then enters the exit sleeve, and finally flows out from the third coolant outlet.

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.

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.

A replacement thermal sleeve with a flange for a reactor vessel closure head penetration adapter housing. By altering a diameter of the flange, a replacement thermal sleeve can be installed through the narrow diameter of the penetration adapter housing opening from under the reactor vessel head. The flange can be compressible or expandable or the tubular wall of the thermal sleeve can be inserted in longitudinal sections, one at a time, into an opening in the underside of the penetration head adapter and reformed within the opening when fully inserted.

Provided is an apparatus for generating electricity, mechanical energy, and/or process and district heat using a gas propellant chamber fueled with fissile material and enclosed in a sealed containment vessel which also contains an operating gas. The system allows for the operating gas to be compressed as it enters the nuclear fuel chamber where it is heated. As the operating gas exits the nuclear fuel chamber, the kinetic energy of the gas is converted to rotational energy by a variety of methods. The rotational energy is further converted to electricity, mechanical energy, and/or process and district heat. The operating gas circulates in the containment vessel and is cooled prior to re-entering the gas propellant chamber. The apparatus thereby provides a simpler and safer design that is both scalable and adaptable. The apparatus is easily and safely transportable and can be designed to be highly nuclear-proliferation-resistant.

Provided is an apparatus for generating electricity, mechanical energy, and/or process and district heat using a gas propellant chamber fueled with fissile material and enclosed in a sealed containment vessel which also contains an operating gas. The system allows for the operating gas to be compressed as it enters the nuclear fuel chamber where it is heated. As the operating gas exits the nuclear fuel chamber, the kinetic energy of the gas is converted to rotational energy by a variety of methods. The rotational energy is further converted to electricity, mechanical energy, and/or process and district heat. The operating gas circulates in the containment vessel and is cooled prior to re-entering the gas propellant chamber. The apparatus thereby provides a simpler and safer design that is both scalable and adaptable. The apparatus is easily and safely transportable and can be designed to be highly nuclear-proliferation-resistant.

Passive safety systems cool reactors using surrounding ground as a heat sink. A coolant flow channel may loop around the reactor and then pass outside, potentially through a containment building, into surrounding ground. No active components need be used in example embodiment safety systems, which may be driven entirely by gravity-based natural circulation. The coolant loop may be air-tight and seismically-hardened and filled with any coolant such as water, air, nitrogen, a noble gas, a refrigerant, etc. The ground may include a soil of grey limestone, soft grey fine sandy clay, grey slightly silty sandy gravel, etc. or any other fill with desired heat-transfer characteristics. Coolant fins and/or jackets with secondary coolants may be used on the coolant loop. The coolant loop may be buried at any constant or variable depth, and the reactor and containment may also be buried in the ground.

A nuclear reactor is designed to couple the load path of the control elements with the reactor core, thus reducing the opportunity for differential movement between the control elements and the reactor core. A cartridge core barrel can be fabricated in a manufacturing facility to include the reactor core, control element supports, and control element drive system. The cartridge core barrel can be mounted to a reactor vessel head, and any movement, such as through seismic forces, transmits an equal direction and magnitude to the control elements and the reactor core, thus inhibiting the opportunity for differential movement.

A nuclear reactor facility may include a reactor building, a reactor vessel housed within the reactor building, and an auxiliary cooling system integrated with the reactor building. The reactor building has a visible section above a ground level and a buried section below the ground level. The reactor vessel contains a fuel core and is housed within the buried section of the reactor building below the ground level. The auxiliary cooling system includes a plurality of ducts integrated with the reactor building and is configured to passively cool the reactor vessel via natural air circulation.