LOCA极端条件下芳香族化合物接枝纳米颗粒提高聚乙烯绝缘性能的作用机理及其优化

核电站失水事故(LOCA)是导致核泄漏、危害人类生存环境的重要原因，提高安全壳内电缆绝缘对LOCA时高剂量率γ线辐射、高温、酸碱液腐蚀极端条件的耐受性，对保障核电安全具有重要意义。本项目提出采用具有高能电子俘获能力的芳香族化合物(AVS)接枝无机纳米颗粒，掺杂改性电缆绝缘材料聚乙烯(PE)。协同发挥AVS和纳米颗粒的散能、阻氧效应和对绝缘性能的调控作用，提高PE的LOCA耐受性。研究LOCA极端条件下复合材料的绝缘和力学性能劣化失效的演变规律和机理，揭示AVS和纳米颗粒在抵御LOCA导致的材料结构、绝缘及力学性能劣化过程中的本质作用，阐明可有效提高PE的LOCA耐受性的添加物结构特征，确立优化的复合材料制备工艺和条件参数。研究结果将有助于理解LOCA极端条件下电缆绝缘劣化失效的机理，也给提高绝缘材料的LOCA耐受性提出了一种全新思路，为保障核电运行安全提供理论和实验依据。

Loss of Coolant Accident (LOCA) occurred in Nuclear Power Plant (NPP) is one of the most serious reasons for nuclear leakage that threatens the living environment of human beings, the improvement of insulation tolerance of power cable installed in the containment to LOCA conditions, including high dose rate gamma-ray irradiation, elevated temperature and erosion of acid/alkali solution, is very important for the safety of NPP. In this project, attempts will be made to employ cable insulation material polyethylene (PE) as the base material and inorganic nanoparticle grafted by aromatic voltage stabilizer (AVS) with the ability to capture high energy electron as the filler to prepare PE based composite, which aims at presenting the ability of the fillers on radiation energy dispersion and oxygen diffusion blocking and on the modulation of insulation performance, so as to improve the PE tolerance to LOCA. It is planned to conduct an in-depth investigation on the effect of LOCA on degradation mechanism of insulation and mechanical properties of the composite, revealing the role of AVS and nanoparticle in resisting the change in material structure, insulation as well as mechanical properties caused by LOCA, extracting the general structure feature of the filler that would effectively improve the tolerance of PE to LOCA, afterwards clarifying the method and the parameters for preparing such composite. Obtained results will help the understanding of cable insulation ageing under LOCA and provide novel idea to the improvement of LOCA tolerance for insulating materials used in NPP, which will provide theoretical and experimental basis for the safe operation of NPP.