Power station in-situ preparation method of neutron flux measurement tube

Abstract

The invention relates to the technical field of nuclear power station maintenance, in particular to a power station in-situ preparation method of a neutron flux measurement tube. The preparation method comprises the following steps that the neutron flux tube is measured by using a 1E-level flexible rule, and after a 2mm margin is reserved on the neutron flux tube according to the preparation requirement, cutting is carried out; after a pipeline beveling machine is assembled, the beveling machine is used for carrying out groove machining verification on pipelines with the same size, the same model and the same material, the size of a groove is checked after machining is completed, and after the size of the groove is confirmed to be correct, groove welding machining is carried out on the cutend of the neutron flux tube; after groove machining is completed, a bullet head is welded to the end of the neutron flux tube through argon arc welding; after cooling, the weld reinforcement is cutoff through a reinforcement removal machine, and it is guaranteed that the weld reinforcement is not lower than that of a base metal after reinforcement removal and the surface smoothness is 1.6; andcheck is carried out by adopting general rules, and after the leakage detection is qualified, the neutron flux tube is stored in a preparation bearing frame for later use. Through the process, the technical conditions of the neutron flux tube to be mounted can be ensured to meet the precision requirement.

Description

technical field [0001] The invention relates to the technical field of nuclear power plant maintenance, in particular to a neutron flux measuring tube power plant on-site preparation method. Background technique [0002] Reactor neutron flux tubes in pressurized water reactor nuclear power plants, commonly known as bushings, are one of the key equipment in pressurized water reactor nuclear power plants. The number of neutron flux tubes varies with the size of the reactor. The number of sub-flux tubes is 20-50. As a measurement channel for the neutron flux of the core nuclear measurement system, the neutron flux tubes are evenly distributed in the channel of the core fuel assembly, run through the fuel assembly, and are exposed in the core. The neutron flux tube is the pressure boundary of the primary circuit, because the mechanical wear caused by radiation embrittlement and flow-induced vibration will make the tube wall thinner or even damaged, which will cause leakage and ...

AI Technical Summary

Problems solved by technology

[0005] During the first installation of the neutron flux tube and during the replacement of the neutron flux tube within the lifetime of the nuclear reactor, it is necessary to cut, form and process the end of the finger sleeve. The preparation process requires high precision, otherwise it may be Resulting in reduced strength and pressure resistance at the end of the neutron flux tube

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