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.

The present disclosure provides a lifting device for lifting a closure head assembly from a reactor vessel body in a nuclear power generation system. The lifting device comprises at least one lifting element having an engagement surface configured to engage an underside surface of the closure head assembly. The at least one lifting element is axially adjustable in height between a retracted position in which its axial height is such that the closure head assembly seals against the body of the reactor vessel and an extended position in which its axial height is such that the closure head assembly is raised above the body of the reactor vessel.

The present disclosure provides a lifting device for lifting a closure head assembly from a reactor vessel body in a nuclear power generation system. The lifting device comprises at least one lifting element having an engagement surface configured to engage an underside surface of the closure head assembly. The at least one lifting element is axially adjustable in height between a retracted position in which its axial height is such that the closure head assembly seals against the body of the reactor vessel and an extended position in which its axial height is such that the closure head assembly is raised above the body of the reactor vessel.

The present disclosure provides a refuelling device for lifting a fuel rod assembly from a reactor core of a nuclear power generation system in a deployment location and transporting it to a storage location. The refuelling device comprises a device body having an open base and defining a chamber for housing a coolant. A sealing plate is movable between an open position in which the chamber is open and a closed position in which the chamber is sealed. The device further comprises a shielding element formed of radioactive shielding material and moveably mounted within the chamber. It has a storage cavity having an open lower end, the shielding element being movable between a retracted position in which it is fully contained within the chamber and an extended position in which it extends from the chamber through the open base of the device body. The device further comprises a rod lifting system having a rod connector for releasable connection to the fuel rod assembly and configured to raise the fuel rod assembly to within the storage cavity when the device is in the deployment location, the sealing plate is in the open position and the shielding element is in its extended position.

The present disclosure provides a refuelling device for lifting a fuel rod assembly from a reactor core of a nuclear power generation system in a deployment location and transporting it to a storage location. The refuelling device comprises a device body having an open base and defining a chamber for housing a coolant. A sealing plate is movable between an open position in which the chamber is open and a closed position in which the chamber is sealed. The device further comprises a shielding element formed of radioactive shielding material and moveably mounted within the chamber. It has a storage cavity having an open lower end, the shielding element being movable between a retracted position in which it is fully contained within the chamber and an extended position in which it extends from the chamber through the open base of the device body. The device further comprises a rod lifting system having a rod connector for releasable connection to the fuel rod assembly and configured to raise the fuel rod assembly to within the storage cavity when the device is in the deployment location, the sealing plate is in the open position and the shielding element is in its extended position.

A combined blade guide and exchange tool, include a blade guide tool having a lower end and an upper end and a plurality of frame rails supporting a pair of lower collet housings at a lower end of the blade guide tool. A pair of fuel support grapple actuating rods are supported between the plurality of frame rails and have a first end engaging a pair of collets within the pair of lower collet housings and a second end disposed at the upper end of the blade guide tool. A blade exchange tool is releasably mounted to the upper end of the blade guide tool and includes a pair of upper collets for engaging the pair of fuel support grapple actuating rods. The blade exchange tool further including a slider and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging a control rod.

A combined blade guide and exchange tool, include a blade guide tool having a lower end and an upper end and a plurality of frame rails supporting a pair of lower collet housings at a lower end of the blade guide tool. A pair of fuel support grapple actuating rods are supported between the plurality of frame rails and have a first end engaging a pair of collets within the pair of lower collet housings and a second end disposed at the upper end of the blade guide tool. A blade exchange tool is releasably mounted to the upper end of the blade guide tool and includes a pair of upper collets for engaging the pair of fuel support grapple actuating rods. The blade exchange tool further including a slider and hook assembly attached to a cable guided by the blade exchange tool and adapted for engaging a control rod.

An extraction device for extracting a nuclear fuel rod or a cluster rod comprises an attachment portion configured to be inserted into a sleeve of the rod through an end without an end plug, and a grip portion, the attachment portion comprising an elongated body along a longitudinal axis and at least one tooth projecting from the body, the or each tooth being configured to allow the attachment portion to be forcibly inserted into the sleeve axially, and to engage with the inner surface of the sleeve so as to prevent the attachment portion from being extracted from the sleeve.

An extraction device for extracting a nuclear fuel rod or a cluster rod comprises an attachment portion configured to be inserted into a sleeve of the rod through an end without an end plug, and a grip portion, the attachment portion comprising an elongated body along a longitudinal axis and at least one tooth projecting from the body, the or each tooth being configured to allow the attachment portion to be forcibly inserted into the sleeve axially, and to engage with the inner surface of the sleeve so as to prevent the attachment portion from being extracted from the sleeve.