Degradation of flame-retardant ethylene-propylene-diene rubber by radiation and steam

Jiayi You*, Hikaru Yamaguchi, Hiroyuki Ishii, Naoshi Hirai, Yoshimichi Ohki*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)1572-1579
Number of pages8
JournalIEEJ Transactions on Electrical and Electronic Engineering
Issue number11
Publication statusPublished - 2020 Nov 1


  • FR-EPR
  • aging
  • complex permittivity
  • elongation at break
  • indenter modulus
  • tensile strength

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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