Underwater replacement system and method for in-core instrumentation in nuclear power plant

Abstract

The invention provides an underwater replacement system and method for an in-core instrumentation in a nuclear power plant. The underwater replacement system and method for the in-core instrumentationin the nuclear power plant are used for replacing the in-core instrumentation in a reactor pit, the reactor pit is internally provided with a shielding water layer with the first preset depth, the underwater replacement system for the in-core instrumentation comprises a pulling-out device, a shearing device, a transferring device and a storage container which are arranged in the shielding water layer, the pulling-out device is used for pulling out the to-be-replaced in-core instrumentation and lifting the to-be-replaced in-core instrumentation to the second preset depth for positioning; the shearing device is used for shearing the positioned in-core instrumentation and real-timely adsorbing chippings generated in the shearing process; and the transferring device is used for loading the sheared in-core instrumentation into the storage container to be stored. According to the underwater replacement system and method for the in-core instrumentation in the nuclear power plant, underwaterreplacement of the in-core instrumentation is achieved, the risk of irradiation is reduced significantly, meanwhile, the operation process is simplified, and the equipment cost and the operation and maintenance management costs are saved.

Description

technical field [0001] The invention relates to the technical field of nuclear power construction, in particular to an underwater replacement system and method for nuclear power plant core measuring instruments. Background technique [0002] The nuclear power plant core measuring instrument enters the reactor from the reactor pressure vessel top cover penetrating piece, and the reactor internals have a supporting and guiding structure for the measuring instrument, and the core measuring instrument can be inserted or withdrawn from the end plug on the top of the supporting and guiding structure. In the conventional design, the service life of the core measuring instrument is less than the reactor life, and the instrument needs to be replaced within a certain period. There are mainly two options for replacing the existing core measurement instruments. One is to set up a special instrument replacement space in the reactor pool, and design a special shielding container for radia...

AI Technical Summary

Problems solved by technology

This method has no radioactive shielding measures when the core instrument is drawn out above the water surface, and the special gripper is easy to interfere with the adjacent instrument when operating the core, and particles may also be generated when the old instrument is sheared, polluting the coolant

[0003] On the other hand, after several fuel cycles, the radioactive dose of the core measurement instrument is relatively high. When the operator uses shielded containers and special equipment to approach the instrument area for replacement, the risk of exposure to radiation is high, and the operation is complicated and takes a long time. It occupies the critical path of refueling and overhaul, which is not conducive to the economic benefits of nuclear power plants; at the same time, when the shielding container is used for replacement operations, the shielding container itself will also become radioactive waste, which is not conducive to the minimization and control of radioactive waste

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