The present application relates to the field of mechanical engineering technologies, and particularly to an unloading device. The unloading device includes a power mechanism, a transmission mechanism, and an execution mechanism that are connected in sequence from top to bottom; wherein the execution mechanism includes a shafting assembly and a turntable assembly that are connected in sequence from top to bottom; wherein the turntable assembly includes an upper auxiliary fence, a middle main disturbance disk, and a lower reclaiming portion that are arranged in sequence from top to bottom. The unloading device provided by the present application is easy to control, and ensures the reclaiming reliability of the spherical materials and the stability of the sphere flow unloading, which can meet the requirements of long life and reliable operation of the unloading device under light load and low speed working conditions and achieve the convenient maintenance.

The present disclosure relates to the technical field of reactor engineering, and particularly, to a nuclear power plant spent fuel negative pressure unloading system, comprising a fuel element transport pipe and a gas transport pipe. The fuel element transport pipe comprises a fuel element output pipe, a fuel element lifting pipe, and a fuel element unloading pipe connected in series. The fuel element unloading pipe is arranged obliquely downward in the direction of fuel element movement. The distal end of the fuel element unloading pipe is connected sequentially to fuel loading apparatus and a transfer apparatus. Two nozzles of the gas transport pipe are connected to set positions on the fuel element output pipe and the fuel element unloading pipe respectively. Gas driving mechanisms are connected to the gas transport pipe. An inlet of the gas driving mechanism is arranged at one end in proximity to the fuel element unloading pipe. The sealed system prevents significant oxidation of a spent fuel element due to high temperature, thus ensuring the integrity of the fuel element in the transfer apparatus, and the safety of the spent fuel unloading system can be ensured.

To manufacture shaped bodies (10) filled with powder (22) for introduction into the reactor core of a commercial nuclear power reactor a plate made of a metal and/or metalloid is provided with one or more blind holes (14), the blind holes (14) are filled with powder (22), the blind holes (14) filled with powder (22) are reversibly sealed and shaped bodies are cut from the plate so that each blind hole (14) filled with powder (22) is surrounded by a shell made of a metal or metalloid. The powder-filled shaped bodies (10) are used in a ball measuring system for commercial nuclear power reactors and/or for the generation of radionuclides in said reactors.