Safety‐related cables in nuclear power plants must be functional even during the occurrence of a severe accident. In this regard, flame‐retardant ethylene‐propylene‐diene rubber (FR‐EPR) widely used for electrical insulation in safety‐related cables was aged under several simulated severe accident conditions. Namely, ⁶⁰Co gamma rays were irradiated at two different dose rates to sheets of FR‐EPR at room temperature or 100°C. After that, saturated or superheated steam was exposed to several sheets at a constant temperature of 155 or 220°C, or at six stepwise elevating temperatures from 120 to 220°C. Various mechanical properties and complex permittivity were measured for these sheets. As a result, the effects of heat, gamma‐ray irradiation, and steam exposure on the degradation of FR‐EPR were clarified. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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辐射和蒸汽对阻燃乙丙橡胶的降解

即使在发生严重事故的情况下，核电厂中与安全相关的电缆也必须能够正常工作。因此，在一些模拟的严重事故情况下，广泛用于安全相关电缆的电气绝缘的阻燃乙丙橡胶（FR-EPR）老化了。即⁶⁰在室温或100°C下，以两种不同的剂量率将γ射线辐照到FR-EPR薄片上。之后，将饱和或过热的蒸汽在155或220°C的恒定温度下，或从120到220°C的六个逐步升高的温度下暴露于几张纸上。测量了这些片材的各种机械性能和复介电常数。结果，阐明了热量，伽马射线辐照和蒸汽暴露对FR-EPR降解的影响。©2020日本电气工程师学会。由Wiley Periodicals LLC发布。