A nuclear reactor core includes a plurality of core assemblies. The core assemblies have a cooperating structure formed at one or more load pads that mechanically couple the plurality of core assemblies together to limit relative motion between core assemblies in a kinematically determinate way. A shear key on one core assembly is configured to fit in a tab slot on an adjacent core assembly. Motion of one core assembly is transferred to a second core assembly and the core assemblies move together.

A nuclear reactor core includes a plurality of core assemblies. The core assemblies have a cooperating structure formed at one or more load pads that mechanically couple the plurality of core assemblies together to limit relative motion between core assemblies in a kinematically determinate way. A shear key on one core assembly is configured to fit in a tab slot on an adjacent core assembly. Motion of one core assembly is transferred to a second core assembly and the core assemblies move together.

Plurality of layers form a nuclear fission reactor structure, each layer having an inner segment body, an intermediate segment body, and an outer segment body (each segment body separated by an interface). The layers include a plurality of cladding arms having involute curve shapes that spirally radiate outward from a radially inner end to a radially outer end. Chambers in the involute curve shaped cladding arm contain fuel compositions (and/or other materials such as moderators and poisons). The design of the involute curve shaped cladding arms and the composition of the materials conform to neutronic and thermal management requirements for the nuclear fission reactor and are of sufficiently common design and/or have sufficiently few variations as to reduce manufacturing complexity and manufacturing variability.

Plurality of layers form a nuclear fission reactor structure, each layer having an inner segment body, an intermediate segment body, and an outer segment body (each segment body separated by an interface). The layers include a plurality of cladding arms having involute curve shapes that spirally radiate outward from a radially inner end to a radially outer end. Chambers in the involute curve shaped cladding arm contain fuel compositions (and/or other materials such as moderators and poisons). The design of the involute curve shaped cladding arms and the composition of the materials conform to neutronic and thermal management requirements for the nuclear fission reactor and are of sufficiently common design and/or have sufficiently few variations as to reduce manufacturing complexity and manufacturing variability.

This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

This disclosure describes various configurations and components of a molten fuel fast or thermal nuclear reactor in which one or more primary heat exchangers are located above the reactor core of the nuclear reactor.

A nuclear reactor including a nuclear reactor core. The nuclear reactor core includes a plurality of moderator elements, and an inverted fuel moderator block array of one or more inverted fuel moderator blocks. The one or more inverted fuel moderator blocks include a high-temperature matrix; a plurality of fuel particles embedded inside the high-temperature matrix; and at least one moderator opening for disposition of at least one of the moderator elements therein. The one or more inverted fuel moderator blocks also include at least one coolant passage formed in the high-temperature matrix to flow a coolant. The nuclear reactor can also include a reactivity control system, which can include one or more control drums, one or more control rods, or a combination thereof.

A nuclear reactor including a nuclear reactor core. The nuclear reactor core includes a plurality of moderator elements, and an inverted fuel moderator block array of one or more inverted fuel moderator blocks. The one or more inverted fuel moderator blocks include a high-temperature matrix; a plurality of fuel particles embedded inside the high-temperature matrix; and at least one moderator opening for disposition of at least one of the moderator elements therein. The one or more inverted fuel moderator blocks also include at least one coolant passage formed in the high-temperature matrix to flow a coolant. The nuclear reactor can also include a reactivity control system, which can include one or more control drums, one or more control rods, or a combination thereof.

Plurality of layers form a nuclear fission reactor structure, each layer having an inner segment body, an intermediate segment body, and an outer segment body (each segment body separated by an interface). The layers include a plurality of cladding arms having involute curve shapes that spirally radiate outward from a radially inner end to a radially outer end. Chambers in the involute curve shaped cladding arms contain fuel compositions (and/or other materials such as moderators and poisons). The design of the involute curve shaped cladding arms and the composition of the materials conform to neutronic and thermal management requirements for the nuclear fission reactor and are of sufficiently common design and/or have sufficiently few variations as to reduce manufacturing complexity and manufacturing variability.

Plurality of layers form a nuclear fission reactor structure, each layer having an inner segment body, an intermediate segment body, and an outer segment body (each segment body separated by an interface). The layers include a plurality of cladding arms having involute curve shapes that spirally radiate outward from a radially inner end to a radially outer end. Chambers in the involute curve shaped cladding arms contain fuel compositions (and/or other materials such as moderators and poisons). The design of the involute curve shaped cladding arms and the composition of the materials conform to neutronic and thermal management requirements for the nuclear fission reactor and are of sufficiently common design and/or have sufficiently few variations as to reduce manufacturing complexity and manufacturing variability.