Experimental Research and Application for Subassembly Coding Automatic Identification of Sodium-cooled Fast Reactor

Abstract

The sodium-cooled fast reactor uses liquid metal sodium as the coolant, and the entire external and internal refueling operations are carried out in a fully enclosed environment, and the operation process of the components is not visible. To ensure the correctness of the sodium-cooled fast reactor components, the design converted the component number into a two-dimensional DataMatrix (DM) code and marked it on the head position of the component through direct identification technology (DPM). An industrial advanced and reliable code reading device (reader) was installed on the new component transfer equipment (new component loader). When the new component was put into the reactor, the code was automatically recognized by the reader, and the component code was converted into a component number and transmitted to the fuel operation monitoring system through communication. The monitoring system compared it with the component numbers in the refueling plan to determine whether the transported new components were correct, improving the reliability and safety of component operations. To determine the size and depth of component codes, 16 component codes consisting of 4 sizes and 4 depths were provided as the test sample library based on the engineering site conditions. In order to determine the optimal component code from the experimental sample library, combined with the engineering site conditions, four main factors affecting the determination of component code were analyzed and summarized through enumeration method: installation angle of code reading equipment, offset angle, component type, and component movement speed. Since these four factors had no interaction with each other, a single factor experimental plan was determined that each experiment only changed one influencing factor, and the rest were fixed as fixed values, which were constant factors. There are a total of 7 tests: control rod assembly code reading test, fuel rod assembly code reading test, reader installation angle code reading test, control rod coding offset angle test, fuel rod coding offset angle test, control rod coding motion test, and fuel rod coding motion test. The judgment basis for each experiment is that the average reading time and maximum reading time of the code reader are less than 500 ms, and the success rate of reading is 100%. Through the first two experiments, the experimental sample library was preliminarily optimized, and then the optimized sample library was used for testing the installation angle of the code reader to screen out the optimal installation angle. Then, the sample library was further streamlined and optimized through encoding offset angle experiments, and finally, the optimal component encoding was determined through encoding motion experiments.

Keywords

• subassembly coding
• test plan
• automatic identification