The Japanese Experiment Module (JEM) is the Japanese contribution to the International Space Station (ISS). The ISS program has established a strategy for managing the risk associated with the micrometeoroid and orbital debris (MM-OD) threat. A shield configuration was designed for the JEM Pressurized Module. Hypervelocity impact (HVI) tests and hydrocode simulations have been conducted to verify the JEM Pressurized Module shield and structural performance for MM-OD impacts. In this paper, we first report the latest hydrocode simulation results for JEM debris shield design evaluation against the strikes of debris. Next, we report the results of hydrocode simulation for large size (5 and 10 cm in diameter) debris impacts on the JEM shield and pressure structure which were conducted to evaluate the penetration hole size in the module wall.