High-temperature gas cooled reactor pebble-bed modular (HTR-PM) uses a dry storage system based on steel storage canisters to store and transport spent fuels on-site. For the canister, one of the key equipment, it is necessary to verify the reliability of the structural design in extreme events, especially under the accidental drop. Since there are 40,000 fuel elements in a canister, interfacial coupling effect between thin-walled storage canister and pebble bed cannot be ignored under the impact. Here, pebble bed and storage canister are modelled by discrete element model and finite element model, respectively. Using this interfacial coupling model, dynamic interactions between the inner surface of canister and spent fuel elements and inside the pebble bed self were analysed numerically. Interactive forces calculated during impact is well applied to diagnose the failure behaviour of fuel elements. The computation results are validated by the full-scale drop test of HTR-PM spent fuel canister.

高温气冷堆卵石床模块（HTR-PM）使用基于钢储罐的干式存储系统来现场存储和运输乏燃料。对于关键设备之一的罐来说，有必要在极端情况下，尤其是在意外跌落的情况下，验证结构设计的可靠性。由于碳罐中有40,000种燃料元素，因此薄壁存储碳罐与卵石床之间的界面耦合作用在冲击下不能忽略。在这里，卵石床和储罐分别通过离散元模型和有限元模型建模。使用该界面耦合模型，对罐内表面和乏燃料元件之间以及卵石床自身内部的动力相互作用进行了数值分析。在撞击过程中计算出的相互作用力可以很好地用于诊断燃料元件的故障行为。HTR-PM乏燃料罐的全面跌落测试验证了计算结果。