Effect of a simulated LOCA testing period on durabilities of insulating and jacketing materials for reactor cables

In the typical examples of LOCA (loss-of-coolant-accident) simulation, presented by IEEE Std 323-1974, the test period was estimated to be three months for BWR and one year for PWR. We studied test conditions which were expected to influence the deterioration of elastomeric materials used in a nuclear reactor, such as heating or cooling rate in the first transient part of a LOCA profile, dose rate effect, and effect of oxygen in the LOCA environment. Studies have progressed since 1979 in JAERI to verify an adequacy of qualification testing method. In this report, we present the effects of an exposure length in a simulated LOCA environment on the degradation of insulating and jacketing materials for reactor cables. In addition, the effect of temperature on the degradation rate of these materials during the cooling phase after a LOCA which follows the first transient phase.