Nuclear power station fuel grid positioning device and method

Abstract

The invention discloses a nuclear power station fuel grid positioning device. The nuclear power station fuel grid positioning device comprises a positioning detection device, a translation mechanism of a hoist and a controller, wherein the positioning detection device is mounted at the bottom end of a hoist boom; the controller is connected with the positioning detection device and the translation device respectively; the positioning detection device comprises at least one proximity sensor; the proximity sensor is used for detecting a gap between the positioning and an inner wall of a fuel grid corresponding to the positioning device after the positioning device drops into the fuel grid, and transmitting a gap signal; the controller is used for calculating a gap deviation according to the gap signal, and transmitting a gap deviation signal in order to control the translation mechanism to perform micro-adjustment; the translation mechanism is used for translating the hoist boom in a micro-adjustment way in order to drive the positioning detection device to be translated in a micro-adjustment way, so that the gap deviation is lower than a preset deviation threshold value in order to obtain the position of a fuel component in the fuel grid. The invention further discloses a nuclear power station fuel grid positioning method. By adopting the positioning device and method, the positioning accuracy and positioning efficiency of the fuel grid can be increased.

Description

technical field [0001] The invention relates to the technical field of nuclear power plants, in particular to a fuel grid positioning device and method for nuclear power plants. Background technique [0002] The nuclear power plant is designed with a spent fuel pool, and a spent fuel storage rack is set in the pool, which can be used to store new fuel and spent fuel assemblies unloaded from the reactor building. The grab, release and transfer of fuel assemblies are mainly realized by a large-span bridge crane (hereinafter referred to as the spent crane). The spent crane includes a translation mechanism and a lifting mechanism. Running in the wide direction, the lifting mechanism drives the gripper to carry the component to do the lifting movement. Spent fuel has strong radioactivity and large decay heat, and contains a considerable amount of fissionable materials. The total gap between the fuel assembly and the storage grid cell is only 11mm. It is very important whether th...

AI Technical Summary

Problems solved by technology

[0005] However, artificial positioning has the following defects: (1) low efficiency

(2) Limited accuracy

Manual trampling work on the fuel grid, Ling Ao Phase II and subsequent projects have introduced foreign matter incidents

Due to the slender structure of the grid, the depth reaches 4425mm, it is extremely difficult to salvage foreign objects, and the grid is easily damaged during the salvage process

(4) Risk of personnel falling

The grid chamber has two specifications of 226mm wide and 250mm wide. When the debugger positions on the grid, it is very easy to step on the air and fall into the chamber. The depth of the chamber reaches 4425mm, which is extremely risky

(5) Cannot be implemented underwater

Since the positioning needs to be manually lowered to the top of the grid, it can only be carried out under dry conditions at present. Once the exhaust pool enters the water and finds that the grid is rusted, it will only cost more than 1,000 cubic meters of boron-containing water to be drained away.

At the same time, once the unit is loaded, the boron-containing water will be radioactive to a certain extent, making personnel at risk of radioactive exposure

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