This paper aims to evaluate the structural dynamic responses and damage/failure of the nuclear fuel reprocessing plant under the free drop impact of spent fuel cask (SFC) and fuel assembly (FA) during the on-site transportation. At the present Part I of this paper, the large-scale SFC model free drop test and the corresponding numerical simulations are performed. Firstly, a composite target which is composed of the protective structure, i.e., a thin RC plate (representing the inverted U-shaped slab in the loading shaft) and/or an autoclaved aerated concrete (AAC) blocks sacrificial layer, as well as a thick RC plate (representing the bottom slab in the loading shaft) is designed and fabricated. Then, based on the large dropping tower, the free drop test of large-scale SFC model with the mass of 3 t is carried out from the height of 7 m–11 m. It indicates that the bottom slab in the loading shaft could not resist the free drop impact of SFC. The composite protective structure can effectively reduce the damage and vibrations of the bottom slab, and the inverted U-shaped slab could relieve the damage of the AAC blocks layer dramatically. Furthermore, based on the finite element (FE) program LS-DYNA, the corresponding refined numerical simulations are performed. By comparing the experimental and numerical damage and vibration accelerations of the composite structures, the present adopted numerical algorithms, constitutive models and parameters are validated, which will be applied in the further assessment of drop impact effects of full-scale SFC and FA on prototype nuclear fuel reprocessing plant in the next Part II of this paper.

本文旨在评估现场运输过程中乏燃料桶（SFC）和燃料组件（FA）自由落体冲击下核燃料后处理厂的结构动力响应和损坏/失效。在本文的第一部分，进行了大型SFC模型自由跌落试验和相应的数值模拟。首先，由保护结构组成的复合靶，即薄 RC 板（代表装载井中的倒 U 形板）和/或蒸压加气混凝土 (AAC) 块牺牲层，以及厚RC板（代表装载井中的底板）被设计和制造。然后，以大型落塔为基础，从7 m~11 m的高度进行了质量为3 t的大型SFC模型的自由落下试验。表明加载井中的底板无法抵抗 SFC 的自由落体冲击。复合保护结构能有效减少底板的损伤和振动，倒U型板能显着减轻AAC砌块层的损伤。此外，基于有限元（FE）程序LS-DYNA，进行了相应的精细数值模拟。通过比较复合结构的实验和数值损伤和振动加速度，验证了目前采用的数值算法、本构模型和参数，将应用于进一步评估全尺寸 SFC 和 FA 对原型核的跌落影响。燃料后处理厂在本文的下一部分中。