Since the submodules as the most important structural component in Water-Cooled Ceramic Breeder (WCCB) Test Blanket Module (TBM) contributes to tritium breeding and extracting, structural integrity assessment is necessary to keep normal operation and function of WCCB TBM-set. Recently, the nonirradiated material properties of F82H which is considered as the structural material of submodule has been summarized following the requirement of RCC-MRx, combined with EU directive, French order, and pressure vessel construction code (RCC-MRx), structural integrity assessment is investigated under the ITER relevant thermo-mechanical load in this study. Meanwhile, cooling water conditions of WCCB TBM-set with its operation scenario, relationship, and detailed values (temperature and pressure) are constituted. Based on the determined structural integrity assessment procedure from RCC-MRx and numerical analysis results, structural integrity of current design of submodule in WCCB TBM-set could be validated. According to the current achievements and established structural integrity assessment procedure, further evaluation on structural integrity combined with electromagnetic load shall be investigated.