Seismic
Protection of a nuclear power station backup generator with a wire rope isolator system
The seismic range considered in nuclear power plant design is much more demanding since the Fukushima catastrophe. The challenge was to come up with an alternative solution to the standard spring box to protect equipment in nuclear stations while filtering earth tremors and the transmitted accelerations.
Socitec devised a decoupling system that uses wire rope isolators, justifying its choice with calculations and characterisation tests. The system was qualified for earthquakes on an electrohydraulic shaker unit by the Sopemea laboratory.
Wire rope isolators were selected due to their inherent elasticity, damping, and large displacement capabilities. The wire rope isolators are also unaffected by temperature, humidity and chemical agents and can last as long as the equipment it protects.
Seismic Protection of the Power Grid
Wire Rope Isolators are used to protect critical power grid components around the world from seismic activity. High-voltage surge arrestors and circuit breakers are especially vulnerable due to their tall, slender structure and fragile (porcelain) insulation materials.
The IEEE Std 693-2005 specifies all substation equipment are designed to withstand earthquakes specific to each region. Socitec Group proprietary SYMOS simulation software and a wire rope isolator base isolation system have been used to provide a cost effective way to protect substation equipment from earthquakes. Their combined properties of large deflection capabilities and inherent damping absorb and dissipate seismic vibrations.