Degradation of insulating polymer materials under LOCA (Loss of Coolant Accident) conditions

An apparatus was constructed to test cables for use in nuclear power plants, under simulated LOCA conditions. The simulator is designed to trace various sorts of LOCA profiles including rapid heating accurately, while the cables are exposed to radiation and electrically energized. By using the simulator, a study was made of the correlation between degradation of insulating polymer materials used in the cables and temperature of the latter period of LOCA simulation. The apparatus and experimental details are described. The materials tested were ethylene-propylene rubber, chlorosulfonated polyethylene, neoprene and silicone rubber. Results are reported and discussed. (U.K.)