A closed-vessel molten salt reactor (cvMSR) is described herein. A cvMSR may comprise a suspended container, such as a metallic container, within a trench surrounded by a concrete enclosure and a concrete cover having a number of channels. The container is rotatable between different orientations. The container may be hollow and a solution of fissile materials and salt materials may be provided within the container. The solution may be capable of undergoing a chain reaction nuclear fission process once a threshold temperature is reached. Heat generated by the solution may heat a fluid surrounding the container. The heated fluid may be transported, through the number of channels of the concrete cover, to an external location where the heated fluid may be used in distributing heat and/or electricity generation.

Position-indexed storage device comprising a support and a basket installed on the support, the basket comprising a plurality of compartments distributed around a longitudinal axis, the basket comprising a central passage with a longitudinal axis, the support comprising a shaft with a longitudinal axis, the shaft being housed in the passage such that relative displacement is possible between the basket and the support along the longitudinal axis, and mechanical means for displacement of the basket relative to the support by a given angle about the longitudinal axis are supported by the internal surface of the passage and the external surface of the shaft, said mechanical displacement means being actuated in each cycle, each cycle comprising a relative separation or approach displacement along the longitudinal axis of the basket and the support.

A travel system (20) for a canister storage, transfer, or transport system generally includes a support structure (22), at least one traveling device (24) for preparing, inspecting, and/or repairing the canister, and a base ring (26) for supporting the traveling device and providing for rotational movement of the traveling device relative to the support structure.

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.