Special Electrical lines designed to operate in severe accident conditions
In case of "Severe Accident" due to reactor core melting, some electrical functions are required. Because of the high temperature and radiation levels reached during and after such an accident, special electrical lines have been designed to assure the transmission of electrical signals from any devices inside the containment building up to the control room.
The SA line is a global concept, covering all the components of the transmission chain of the signal. The SA line starts from the SA device, goes outside containment through the Electrical Penetration, while maintaining the electrical integrity and pressure boundary of the containment building.
The SA line uses Mineral Insulated Calbes (MIC) and hermetic connectors. The MIC lines are connected on side to the Electrical Penetration and in the other side to the devices (Transmitters, limit switches, Thermocouples). Low voltage power supply MIC lines are also available.
The SA lines are composed of:
- SA Conductor Feedthroughs in the Electrical Penetration: Special Conductor feedthroughs are mounted within the Electrical penetration assembly. These feedthroughs are composed of 3 MIC cables with either 2 or 4 copper conductors or a pair of thermocouples. These MIC cables are terminated with the "SA" hermetic connectors (see note) for inside containment connection. The matching part of the connector is provided with the CIMGRIP Line.
- CIMGRIP (™) lines for Temperature measurements: The MIC thermocouple (K or C) is terminated by an SA hermeric connector. The Line between the MIc Thermocouple and the penetration feedthrough is composed of a CIMGRIP extension cable with integrated "SA" hermetic connectors at each extremity matching the Thermocouple in one side and the MIC feedthrough in the other side.
- CIMGRIP (™) lines for signal transmission: The signal transmission Line between the "SA" device and the penetration feedthrough is composed of a CIMGRIP cable with 4 copper cores with "SA" hermetic connectors at each extremity matching the device in one side and the MIC feedthrough in the other side.
- "SA" socket connector: "SA" socket connector is welded on the "SA" device (transmitter, limit switch....)
The completed "SA" Lines, including the "SA" Feedthroughs of the penetration, the CIMGRIP cable and the related "SA" hermetic connectors are fully qualified according to EPR LOCA + "Severe Accident" conditions
- Thermal Ageing (60 years life)
- Radiation (cumulated dosage 2,77 MGy)
- Loca+SA profile
- 60 cycles coupling/decoupling connector.