According to the simulation results and the experimental study of 45 ° test block, the ductile iron spent fuel container adopts the metal mold casting process, the outer side of the ductile iron spent fuel container adopts the metal mold, and the inner side adopts the direct external chill iron. The casting process of the spherical iron spent fuel container is shown in Figure 1. According to the results of simulation analysis, the casting process of ductile iron spent fuel container is optimized.
The diameter of hot spot circle of 100 ton ductile iron spent fuel container is more than 630mm. The solidification characteristics of hot spot are analyzed, and the casting process is adjusted and optimized according to the solidification characteristics of hot spot. The first chapter is to confirm that the ductile iron spent fuel container adopts the metal mold casting process, and to analyze the solidification characteristics of the hot spot under the metal mold casting process. This section analyzes the solidification and defects of ductile iron spent fuel container under the metal mold process, and provides direction and guidance for the optimization direction of its casting process. The solidification time distribution and defect distribution of hot spot of ductile iron spent fuel container in 300 mm metal mold casting process are shown in Figure 2.
Analysis of Figure 2 shows that the hot spot of nodular iron nuclear spent fuel container is finally solidified, and each layer of the hot spot solidifies to form a closed “ring”, and the layers are completely isolated. After the solidification of each layer is completed, it is difficult for the molten iron in the riser and uncooled parts to supplement the hot spot, and the tendency of shrinkage defects in the hot spot increases. Therefore, the capacity of nodular iron nuclear spent fuel container should be accelerated On the other hand, the solidification of the body part and the hot spot part of the spent fuel container should be coordinated to ensure the consistency of the structure and performance of the spent fuel container.