Levet A, Colombani J, Duponchel L
IRSN/PSN-RES, Cadarache, St Paul lez Durance 13115, France; LASIR CNRS UMR 8516, Université Lille 1, Sciences et Technologies, 59655 Villeneuve d'Ascq Cedex, France.
IRSN/PSN-RES, Cadarache, St Paul lez Durance 13115, France.
Talanta. 2017 Sep 1;172:139-146. doi: 10.1016/j.talanta.2017.05.046. Epub 2017 May 16.
Due to the willingness to extend the nuclear power plants length of life, it is of prime importance to understand long term ageing effect on all constitutive materials. For this purpose gamma-irradiation effects on insulation of instrumentation and control cables are studied. Mid-infrared spectroscopy and principal components analysis (PCA) were used to highlight molecular modifications induced by gamma-irradiation under oxidizing conditions. In order to be closer to real world conditions, a low dose rate of 11Gyh was used to irradiate insulations in full cable or alone with a dose up to 58 kGy. Spectral differences according to irradiation dose were extracted using PCA. It was then possible to observe different behaviors of the insulation constitutive compounds i.e. ethylene vinyl acetate (EVA), ethylene propylene diene monomer (EPDM) and aluminium trihydrate (ATH). Irradiation of insulations led to the oxidation of their constitutive polymers and a modification of filler-polymer ratio. Moreover all these modifications were observed for insulations alone or in full cable indicating that oxygen easily diffuses into the material. Spectral contributions were discussed considering different degradation mechanisms.
由于延长核电站使用寿命的意愿，了解所有组成材料的长期老化效应至关重要。为此，研究了伽马辐射对仪表和控制电缆绝缘的影响。利用中红外光谱和主成分分析（PCA）来突出氧化条件下伽马辐射引起的分子变化。为了更接近实际情况，采用11Gy/h的低剂量率对整根电缆中的绝缘材料或单独的绝缘材料进行辐照，剂量高达58kGy。使用PCA提取根据辐照剂量的光谱差异。然后可以观察到绝缘组成化合物，即乙烯醋酸乙烯酯（EVA）、乙丙二烯单体（EPDM）和三水合铝（ATH）的不同行为。绝缘材料的辐照导致其组成聚合物的氧化以及填料-聚合物比例的改变。此外，无论是单独的绝缘材料还是整根电缆中的绝缘材料都观察到了所有这些变化，这表明氧气很容易扩散到材料中。考虑到不同的降解机制对光谱贡献进行了讨论。
