A passive self-adaptive multifunctional detection device for nuclear fuel assemblies

Abstract

The invention provides a passive adaptive multifunctional detection device for a nuclear fuel assembly. The detection device includes an oxide film thickness detection mechanism, a probe flexible feeding mechanism and a deformation detection mechanism. The deformation detection mechanism is in contact with the to-be-detected nuclear fuel assembly. The probe flexible feeding mechanism is in rigid connection with the oxide film thickness detection mechanism and the deformation detection mechanism separately. The oxide film thickness detection mechanism includes a probe spline groove, a spline slide block, an eddy current probe, a guide wheel support and a guide wheel. The deformation detection mechanism includes a mounting housing, an end cover, an outer rotary rack, an inner rotary rack, apedestal, a connection rod, an LVDT sensor and a sleeve. The device is simple and compact in structure, convenient in mounting, good in sealing performance, can adapt to different transformation and attitudes of fuel rods, can have flexible contact with the fuel rods and performs flexible measurement on the fuel rods and has multiple detection functions.

Description

technical field [0001] The invention relates to the field of nuclear industry detection, in particular to a passive self-adaptive multifunctional detection device for nuclear fuel assemblies. Background technique [0002] Fuel rods are composed of hundreds of uranium dioxide ceramic pellets and zirconium alloy material cladding. Nuclear fuel assembly refers to the whole group that assembles several fuel rods, upper and lower tube seats, control rod guide tubes and positioning grids. fuel rods. The nuclear fuel assembly has the advantages of high output power, convenient loading and unloading, etc. It is the core component of the nuclear power plant. During the operation of the nuclear reactor, the nuclear fuel assembly is immersed in the coolant / moderator located in the core of the nuclear reactor, due to the oxidation reaction between the used coolant / moderator and the zirconium in the cladding of the zirconium alloy material, zirconium oxidation will accumulate on the nuc...

AI Technical Summary

Problems solved by technology

[0003] At present, in view of the safe operation of nuclear power plants, systematic and in-depth research work has been carried out at home and abroad on the detection of key parameters of nuclear fuel assemblies, and a variety of detection equipment have been developed, such as the patent document "The detector and the thickness of the oxide film of the fuel rod including the detector Measuring device (CN102867555A)" discloses a detector and a fuel rod oxide film thickness measuring device including the detector, which can be realized through the eddy current sensor while the detector equipped with an eddy current sensor and a conveying roller moves up and down. The detection of cladding oxide film thickness, but because the transmission area of ​​the detection device is parallel to the transmission support area, it cannot adapt to the local deformation of the nuclear fuel assembly. Counterpoint; the patent document "Spent Fuel Assembly Multifunctional Detection Equipment (CN107180658A)" discloses a spent fuel assembly multifunctional detection equipment, using the oxide film and diameter measurement module installed on the self-adaptive floating platform to simultaneously measure the fuel rod oxide film Accurately measure the thickness and diameter, install the adaptive floating platform on the two-degree-of-freedom transfer platform, realize the self-adaptive adjustment of the four-degree-of-freedom measurement module in the horizontal and vertical directions, and solve the alignment problem between the spent fuel assembly and the measurement module, making The local deformation of the spent fuel assembly can be adaptive and effectively protect the spent fuel assembly, but it cannot provide effective data on the relative displacement between the detection probe and the nuclear fuel assembly, and its measurement accuracy is limited; in addition, the micro displacement sensor can also be used for fuel rod oxidation The measurement of thickness, such as the patent document "the device and method for measuring the diameter of dense tube bundle and the thickness of oxide film on site (CN107274941A)" relates to a device and method for measuring the diameter of dense tube bundle and the thickness of oxide film on site. The three-dimensional mobile platform cooperates with the installation groove and the guide wheel to realize the self-adaptive alignment of the nuclear fuel assembly and the measurement module, and realizes the accurate measurement of the thickness of the oxide film. Adaptation, its safety guarantee is poor, and its diameter detection module is arranged separately from the oxide film detection module, which cannot realize multi-parameter detection of nuclear fuel assemblies at the same time

[0004] To sum up, the existing detection devices have preliminarily realized the detection of key parameters such as the oxide film thickness of nuclear fuel assemblies through different detection methods, but most detection devices cannot simultaneously perform multi-parameter detection of nuclear fuel assemblies, resulting in low measurement efficiency. ; The relative displacement and positioning accuracy between the detection probe and the nuclear fuel assembly are poor, resulting in low measurement accuracy; the alignment between the detection probe and the nuclear fuel assembly is complicated; the inability to adapt to the local deformation of the nuclear fuel assembly results in poor safety assurance

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