Provided is a method for manufacturing a cylindrical member which includes end bending of respective end portions of a plate material in a longitudinal direction, primary grooving of respective end surfaces of the plate material subjected to end bending, bending of the plate material to a ring shape, secondary grooving of respective end surfaces of the plate material subjected to bending in a ring shape, and joining of respective end surfaces of the plate material. Therefore, it is possible to manufacture a high-quality cylindrical member.

Provided is a method for manufacturing a cylindrical member which includes end bending of respective end portions of a plate material in a longitudinal direction, primary grooving of respective end surfaces of the plate material subjected to end bending, bending of the plate material to a ring shape, secondary grooving of respective end surfaces of the plate material subjected to bending in a ring shape, and joining of respective end surfaces of the plate material. Therefore, it is possible to manufacture a high-quality cylindrical member.

A nuclear reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing and to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing, a shaft travel pin to control the travel of the shaft, and a flange to mount the support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

A centering pin for a nuclear reactor core within a reactor vessel includes a central part having a radially inner edge oriented toward the core and a horizontal thickness along the radially inner edge. The pin includes an upper hydrodynamic profile, which is disposed above the central part and forms a vertical wing leading edge extending from the central part and having an upper height above the central part. The pin includes a lower hydrodynamic profile, which is disposed below the central part and forms a vertical wing trailing edge extending from the central part and having a lower height below the central part. The upper height has a maximum variation of more or less 25% relative to the horizontal thickness. The lower height has a maximum variation of more or less 25% relative to the horizontal thickness.

A centering pin for a nuclear reactor core within a reactor vessel includes a central part having a radially inner edge oriented toward the core and a horizontal thickness along the radially inner edge. The pin includes an upper hydrodynamic profile, which is disposed above the central part and forms a vertical wing leading edge extending from the central part and having an upper height above the central part. The pin includes a lower hydrodynamic profile, which is disposed below the central part and forms a vertical wing trailing edge extending from the central part and having a lower height below the central part. The upper height has a maximum variation of more or less 25% relative to the horizontal thickness. The lower height has a maximum variation of more or less 25% relative to the horizontal thickness.

A nuclear reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing, a shaft travel pin, and a flange. The shaft is configured to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing. The shaft travel pin controls the travel of the shaft. The flange is configured to mount the nuclear reactor core mechanical support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

A nuclear reactor core mechanical support bracket is disclosed. The support bracket includes a housing, a spring disposed internally within the housing, a shaft slidingly disposed within the housing, a shaft travel pin, and a flange. The shaft is configured to engage the spring to compress and decompress the spring as the shaft travels in and out of the housing. The shaft travel pin controls the travel of the shaft. The flange is configured to mount the nuclear reactor core mechanical support bracket to a canister of a nuclear reactor. The shaft includes an inset configured to interface with a nuclear reactor core component.

A modular nuclear reactor system includes a lift-out, replaceable nuclear reactor core configured for replacement as a singular unit during a single lift-out event, such as rather than lifting and replacing individual fuel assemblies and/or fuel elements. The system includes a reactor vessel and a power generation system configured to convert thermal energy in a high temperature working fluid received from the reactor vessel into electrical energy. The reactor vessel includes: a vessel inlet and an adjacent vessel outlet arranged near a bottom on the vessel; a vessel receptacle configured to receive a unified core assembly; locating datums in the base of the vessel receptacle and configured to constrain a core assembly in multiple degrees of freedom; and an interstitial zone surrounding the vessel receptacle and housing a set of control or moderating drums.

A modular nuclear reactor system includes a lift-out, replaceable nuclear reactor core configured for replacement as a singular unit during a single lift-out event, such as rather than lifting and replacing individual fuel assemblies and/or fuel elements. The system includes a reactor vessel and a power generation system configured to convert thermal energy in a high temperature working fluid received from the reactor vessel into electrical energy. The reactor vessel includes: a vessel inlet and an adjacent vessel outlet arranged near a bottom on the vessel; a vessel receptacle configured to receive a unified core assembly; locating datums in the base of the vessel receptacle and configured to constrain a core assembly in multiple degrees of freedom; and an interstitial zone surrounding the vessel receptacle and housing a set of control or moderating drums.

A nuclear reactor has first and second plenum plates disposed in a pressure vessel. Both plenum plates have a plurality of apertures. The second plenum plate is parallel to the first plenum plate. A fuel element includes a fuel element coolant flow tube which extends through aligned apertures of the parallel plenum plates. A fuel element standoff spool is disposed about a portion of the fuel element coolant flow tube which is located between the plenum plates. The nuclear reactor is also usable in nuclear thermal propulsion.