경수로 핵연료 지지격자체의 횡방향 충격강도 향상 방안 연구

The spacer grid assembly is one of the main structural components of the nuclear fuel assembly of a PWR. The spacer grid assembly supports and aligns the fuel rods, guides the fuel assemblies past each other during handling and, if needed, sustains lateral seismic loads. The ability of the spacer grid assembly to resist the lateral loads is usually characterized in terms of its dynamic and static crush strengths, which are acquired from tests. In this study, a finite element analysis on the dynamic crush strength of spacer grid assembly specimens is carried out. And also a parametric study on the crush strength of a spacer grid assembly is carried out by adjusting the weld bead size and weld penetration depth. Comparisons show that the analysis results are in good agreement with the test results to within an 8 % difference range.