Insulations and Jackets for Control and Power Cables in Thermal Reactor Nuclear Generating Stations

The permanent change in the physical strengths, rate of oxidation, dielectric loss, and electrical stability in 40-psig (142°C) steam and dielectric strength are reported for 13 elastomer-based insulation-jacket combinations after irradiation up to 108 rad in air at 5 ×105 rad/h from a cobalt 60 source. Threshold of damage for each property, overall threshold of damage, and highest dose rate still serviceable for the combinations are summarized. On the basis of these date, suggestions are made for IEEE nuclear environment classification of cable coverings rate for continuous 90°C and higher.