While the described systems can include any suitable component, in some cases, they include a graphite reactor core defining an internal space that, in some cases, houses one or more fuel wedges, where each wedge defines one or more fuel channels that extend from a first end to a second end of the wedge. In some cases, one or more of the fuel wedges comprise multiple wedge sections that are coupled together end to end and/or in any other suitable manner. In some cases, one or more alignment pins also extend between two sections of a fuel wedge to align the sections. In some cases, one or more seals are also disposed between two sections of a fuel wedge. Thus, in some cases, the reactor core can be relatively long (e.g., to be a pipeline reactor). In some cases, the reactor core is also disposed within a graphite reflector. Other implementations are described.

While the described systems can include any suitable component, in some cases, they include a graphite reactor core defining an internal space that, in some cases, houses one or more fuel wedges, where each wedge defines one or more fuel channels that extend from a first end to a second end of the wedge. In some cases, one or more of the fuel wedges comprise multiple wedge sections that are coupled together end to end and/or in any other suitable manner. In some cases, one or more alignment pins also extend between two sections of a fuel wedge to align the sections. In some cases, one or more seals are also disposed between two sections of a fuel wedge. Thus, in some cases, the reactor core can be relatively long (e.g., to be a pipeline reactor). In some cases, the reactor core is also disposed within a graphite reflector. Other implementations are described.

Nuclear fuel spacers include a deflection-limited elastic rod contact. Spacers may additionally include a rigid contact without elastic functionality. A degree of deflection may be chosen based on plastic deformation threshold, maximum fuel rod movement, anticipated transverse loads related to fuel assembly, inspection, handling, transportation, operation, accidents, and/or any other operating characteristic. Spacers include deflection-limited elastic contacts and/or rigid contacts in several arrangements within the spacer and/or on a single fuel rod. Spacers are compatible with a simple fabrication method that forms rigid, deflection-limiting, and elastic components from a single substrate. Nuclear fuel spacers are useable with several fuel assembly types.

Nuclear fuel spacers include a deflection-limited elastic rod contact. Spacers may additionally include a rigid contact without elastic functionality. A degree of deflection may be chosen based on plastic deformation threshold, maximum fuel rod movement, anticipated transverse loads related to fuel assembly, inspection, handling, transportation, operation, accidents, and/or any other operating characteristic. Spacers include deflection-limited elastic contacts and/or rigid contacts in several arrangements within the spacer and/or on a single fuel rod. Spacers are compatible with a simple fabrication method that forms rigid, deflection-limiting, and elastic components from a single substrate. Nuclear fuel spacers are useable with several fuel assembly types.

Systems and methods for providing and using molten salt reactors are described. While the systems can include any suitable component, in some cases, they include a graphite reactor core defining an internal space that houses one or more fuel wedges, where each wedge defines one or more fuel channels that extend from a first end to a second end of the wedge. In some cases, one or more of the fuel wedges comprise multiple wedge sections that are coupled together end to end and/or in any other suitable manner. In some cases, one or more alignment pins also extend between two sections of a fuel wedge to align the sections. In some cases, one or more seals are also disposed between two sections of a fuel wedge. Thus, in some cases, the reactor core can be relatively long (e.g., to be a pipeline reactor). Other implementations are also described.

Systems and methods for providing and using molten salt reactors are described. While the systems can include any suitable component, in some cases, they include a graphite reactor core defining an internal space that houses one or more fuel wedges, where each wedge defines one or more fuel channels that extend from a first end to a second end of the wedge. In some cases, one or more of the fuel wedges comprise multiple wedge sections that are coupled together end to end and/or in any other suitable manner. In some cases, one or more alignment pins also extend between two sections of a fuel wedge to align the sections. In some cases, one or more seals are also disposed between two sections of a fuel wedge. Thus, in some cases, the reactor core can be relatively long (e.g., to be a pipeline reactor). Other implementations are also described.

Insulated fuel assembly core with axially arranged fuel monoliths including channels and having a composition including a fissionable fuel component, exhaust support plate, exhaust shield assembly, and insulation layer. Fuel monoliths have an eccentric cylinder shape or a right circular cylinder shape with side surface keyway. The eccentric shape and/or a keyway (with associated alignment rod) provide alignment. Channels in the exhaust support plate are oriented so propellant gas flowing from the fuel monoliths through the exhaust support plate does not impinge the exhaust shield assembly. Insulated fuel assembly cores are manufactured by forming a tensioned fuel monolith stack mandrel assembly using mandrel spacers and internal tensioning components and mandrel winding an insulation layer on an outer surface of the tensioned fuel monolith stack mandrel assembly. Insulated fuel assembly cores can be incorporated into fuel assemblies of nuclear propulsion fission reactor structures, for example, a nuclear thermal propulsion engine.

Insulated fuel assembly core with axially arranged fuel monoliths including channels and having a composition including a fissionable fuel component, exhaust support plate, exhaust shield assembly, and insulation layer. Fuel monoliths have an eccentric cylinder shape or a right circular cylinder shape with side surface keyway. The eccentric shape and/or a keyway (with associated alignment rod) provide alignment. Channels in the exhaust support plate are oriented so propellant gas flowing from the fuel monoliths through the exhaust support plate does not impinge the exhaust shield assembly. Insulated fuel assembly cores are manufactured by forming a tensioned fuel monolith stack mandrel assembly using mandrel spacers and internal tensioning components and mandrel winding an insulation layer on an outer surface of the tensioned fuel monolith stack mandrel assembly. Insulated fuel assembly cores can be incorporated into fuel assemblies of nuclear propulsion fission reactor structures, for example, a nuclear thermal propulsion engine.

While the described systems can include any suitable component, in some cases, they include a graphite reactor core defining an internal space that, in some cases, houses one or more fuel wedges, where each wedge defines one or more fuel channels that extend from a first end to a second end of the wedge. In some cases, one or more of the fuel wedges comprise multiple wedge sections that are coupled together end to end and/or in any other suitable manner. In some cases, one or more alignment pins also extend between two sections of a fuel wedge to align the sections. In some cases, one or more seals are also disposed between two sections of a fuel wedge. Thus, in some cases, the reactor core can be relatively long (e.g., to be a pipeline reactor). In some cases, the reactor core is also disposed within a graphite reflector. Other implementations are described.

Systems and methods for providing and using molten salt reactors are described. While the systems can include any suitable component, in some cases, they include a graphite reactor core defining an internal space that houses one or more fuel wedges, where each wedge defines one or more fuel channels that extend from a first end to a second end of the wedge. In some cases, one or more of the fuel wedges comprise multiple wedge sections that are coupled together end to end and/or in any other suitable manner. In some cases, one or more alignment pins also extend between two sections of a fuel wedge to align the sections. In some cases, one or more seals are also disposed between two sections of a fuel wedge. Thus, in some cases, the reactor core can be relatively long (e.g., to be a pipeline reactor). Other implementations are also described.