Abstract: Disclosed is a method of tensioning/detensioning closure studs of a nuclear reactor vessel. The closure studs are spaced about a circumference of the reactor vessel so as to attach an integrated head package (IHP) of the reactor vessel to a body of the reactor vessel. The method comprises supporting a first stud tensioner device on a trolley, moving the trolley across a movement surface from a stored position to a deployment position adjacent the reactor vessel, engaging the first stud tensioner device with one or more of the closure studs, and operating the first stud tensioner device to tension/detension the one or more closure studs.

Abstract: The present disclosure provides an integrated head package for a nuclear power generation system, the integrated head package comprising a closure head, and a control rod drive mechanism housed within a shroud. The control rod drive mechanism comprises at least one drive rod extending through the closure head and having a coupling element for releasably coupling to a control rod assembly within a reactor core. The at least one drive rod is movable to a maintenance/refuelling position in which the at least one drive rod is uncoupled from the control rod assembly and at least partially retracted into the integrated head package. The integrated head package further comprises at least one engagement feature for securing the at least one drive rod in the maintenance/refuelling position.

Abstract: Disclosed is a nuclear power generation system comprising a reactor vessel comprising a body defining a cavity housing a reactor core, and an integrated head package having a closure head for closing an opening to the cavity. The system also comprises a containment structure having a working floor surrounding and substantially vertically aligned with the opening to the cavity.

Abstract: The present disclosure provides a lifting and transport device for lifting upper internals from a reactor core of a nuclear power generation system in a deployment location and transporting them to a storage location. The lifting/transport device comprises a device body formed of radioactive shielding material, the device body defining a storage chamber having an open base. The device further comprises a movable sealing plate formed of radioactive shielding material, the sealing plate being movable between an open position in which the storage chamber is open and a closed position in which the storage chamber is sealed. There is also a lifting system mounted within the storage chamber having a lifting rig for releasable connection to the upper internals and configured to raise the upper internals to within the storage chamber when the device is in the deployment location and the plate is in the open position.

Abstract: 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.

Abstract: 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.