A fuel assembly (1) for a nuclear power plant includes at least one hollow rod (9, 9a,9b, 9c). The hollow rod is a control rod guide tube (9) of the fuel assembly (1) for the control rod assembly or an instrumentation tube. Each rod (9) is adapted to be filled with one or more containers (38) filled with material to be activated. The fuel assembly further comprises a damping element (36, 36a, 36b, 36c) at the lower end (32) of the hollow rod (9, 9a,9b, 9c).

A robotic arm for handling fuel in a nuclear reactor is provided, the robotic arm comprising a movement mechanism for moving the robotic arm along an x-axis. The movement mechanism can be coupled to an arm portion whose centre line is parallel with the x-axis, a grab head portion which is pivotally mounted to the arm portion. The grab head can be rotated vertically to be parallel to a z-axis, and have a telescopic portion that allows the grab head to extend along the z-axis and a grip mechanism at its distal end for gripping fuel assemblies of the nuclear reactor.

A robotic arm for handling fuel in a nuclear reactor is provided, the robotic arm comprising a movement mechanism for moving the robotic arm along an x-axis. The movement mechanism can be coupled to an arm portion whose centre line is parallel with the x-axis, a grab head portion which is pivotally mounted to the arm portion. The grab head can be rotated vertically to be parallel to a z-axis, and have a telescopic portion that allows the grab head to extend along the z-axis and a grip mechanism at its distal end for gripping fuel assemblies of the nuclear reactor.

Fuel cell lifting systems for nuclear reactors are disclosed. A fuel cell lifting system includes a radiation shield comprising: a first plate defining a first plane and comprising one or more first openings; and a second plate defining a second plane parallel to the first plane and comprising one or more second openings. At least one of the first plate or the second plate is rotatable around an axis perpendicular to the first plane and the second plane. A first opening of the first plate can be aligned with a second opening of the second plate to form a combined opening. A lifting motor is configured to extend and retract a tether through the combined opening of the radiation shield. The tether is attachable to a nuclear fuel cell.

Fuel, heat exchangers, and instrumentation for nuclear reactors are disclosed. A nuclear power system includes a plurality of nuclear fuel elements, each of the nuclear fuel elements including an annulus; and a plurality of heat pipes, each of the plurality of heat pipes configured to pass through the annulus of a respective one of the nuclear fuel elements in conductive thermal contact with the respective nuclear fuel element. A nuclear instrumentation module includes an assembly of optical fibers, each optical fiber comprising one or more sensors and configured for removable installation at one of the plurality of heat pipes. A heat exchanger includes a heat pipe including an evaporating region and a condensing region; and a tube bundle configured to wrap around the condensing region of the heat pipe and including one or more adjacent, parallel tubes, each tube forming a helix that is coaxial to the heat pipe.

An in-vessel fuel transfer machine may be permanently affixed to a nuclear reactor and remain in place during power operations. The in-vessel fuel transfer machine may include a pantograph machine that positions a grapple in order to access any fuel socket location within the core and move any of the core assemblies between the core, an in-vessel fuel storage area, and a fuel elevator. The grapple may be positioned through a combination of movements, such as, rotating a rotating plug assembly, rotating the in-vessel fuel transfer machine, extending the pantograph arms, and shuttling the grapple along a leg. The grapple may be compliant to accommodate deformed core assemblies and may be configured to pivot to more closely align to an eccentric core assembly handling socket or be moveable in a horizontal plane to accommodate a deformed core assembly during insertion or withdrawal.

An in-vessel fuel transfer machine may be permanently affixed to a nuclear reactor and remain in place during power operations. The in-vessel fuel transfer machine may include a pantograph machine that positions a grapple in order to access any fuel socket location within the core and move any of the core assemblies between the core, an in-vessel fuel storage area, and a fuel elevator. The grapple may be positioned through a combination of movements, such as, rotating a rotating plug assembly, rotating the in-vessel fuel transfer machine, extending the pantograph arms, and shuttling the grapple along a leg. The grapple may be compliant to accommodate deformed core assemblies and may be configured to pivot to more closely align to an eccentric core assembly handling socket or be moveable in a horizontal plane to accommodate a deformed core assembly during insertion or withdrawal.