Device and method for detecting green body strength of nuclear fuel element

Abstract

The invention discloses a device for detecting green body strength of a nuclear fuel element. The device comprises a base, a vertical sliding mechanism, a clamping mechanism and a force measuring mechanism, wherein the vertical sliding mechanism is fixedly arranged on the base along a vertical direction; the clamping mechanism is transversely arranged along a horizontal direction; the clamping mechanism is provided with a mounting part and a clamping part used for clamping a green body; the mounting part of the clamping mechanism is connected with the vertical sliding mechanism in a sliding manner, so that the clamping mechanism can slide up and down along the vertical direction, and the vertical sliding mechanism can control the vertical sliding height of the clamping mechanism; the force measuring mechanism comprises a force measuring sensor and an impact plate which is transversely arranged along the horizontal direction; the impact plate is arranged on the base and positioned just under the clamping part of the clamping mechanism; and the force measuring sensor is mounted on the impact force to be used for detecting the impact force of the green body. The invention further provides a method for detecting the core block strength by using the device. The method is capable of effectively detecting external impact force stressed by a fuel core block, and has the advantages of small measuring error, stable and accurate data and the like, and is capable of greatly improving the detection efficiency.

Description

technical field [0001] The invention relates to a nuclear fuel green body strength detection technology, in particular to a nuclear fuel element green body strength detection device and detection method. Background technique [0002] A fuel element green body, also known as a fuel pellet, is a small, usually cylindrical, stack of fuel elements stacked within a cladding to build a fuel element. Green fuel is the core part of the fuel element. In the field of nuclear fuel, uranium oxide, thorium oxide, plutonium oxide, uranium dioxide pellets (UO2) and other oxides are widely used. Among them, uranium dioxide pellets (UO2 ) is the main fuel for all light water reactors and heavy water reactors. At present, nuclear power plants at home and abroad widely use uranium dioxide pellets as nuclear fuel elements. In order to ensure the safe operation of reactors, very strict quality indicators have been formulated for nuclear fuel elements. Among many quality indicators, the density ...

AI Technical Summary

Problems solved by technology

However, there are the following deficiencies in manually detecting the strength of the pellets: 1. The aforementioned process of applying an external impact to the fuel pellets is generally to clamp the pellets vertically in a mechanism, and after confirming that the pellets are locked, operate the pressure plate from top to bottom The impact force is applied, but the size of the impact force cannot be detected. Since the impact force provided by the outside is not constant each time, a large impact force may cause a large amount of broken and fallen powder particles, and a small impact force may cause crushing. The amount of cracked powder particles is small, which makes the error of the pellet strength detection large and the reliability is not high

2. Since manual detection cannot accurately control the external impact force, when the same fuel pellet is tested multiple times, the repeatability error of manual detection results will be relatively large

3. Manual testing can only detect the strength of the pellet in the vertical direction, that is, it can only measure the impact force in a single direction of the pellet. If the strength of a certain part of the pellet is high and the strength of other parts is low, the pellet The measurement data of the strength is very inaccurate, poor in stability, and cannot reflect the overall strength of the pellet

4. The calculation of the strength of the fuel pellets is unreasonable, and the impact force on the fuel pellets is not considered in the calculation, resulting in poor accuracy of the test results of the pellet strength

5. Manual measurement of a single pellet often takes more than 2 minutes, and the detection efficiency is low, which can no longer meet the efficiency requirements of modern production lines

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