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Our Business / Thermal Power StationsSeismic Countermeasures

Aseismic Design

During construction, aseismic design is implemented based on relevant laws such as the Building Standards Act, the Fire Service Act, “Rules of Quality Assurance for Safety of Nuclear Power Plants (JEAC)”, etc. After construction, seismic performance is periodically checked through facility inspections.

Countermeasures Considering the Experience of Previous Facility Damages

We have implemented individual countermeasures in consideration of the damage caused by the earthquakes that caused serious damage to facilities.

[Individual Countermeasures]

  • Building reinforcement (main turbine building and main administrative building) based on old aseismic design standards
  • Measures against sloshing* of fuel tanks (strengthening floating roof function -> forming double-deck)
  • Measures against foundational differential settlement for transformers, fire extinguishing pipes, etc.
    *Shaking fuels in the tank due to relatively long-period oscillations by an earthquake. This sloshing fuel can cause massive problems such as destroying the floating roof of the fuel tank or overflowing from the tank.
  • *Forming Double-Deck for Floating Roof
Measures against Sloshing of Fuel Tank
Measures against Sloshing of Fuel Tank (Schematic)

Aseismic Reinforcement

For earthquakes announced by public organizations like the Central Disaster Prevention Council, aseismic evaluation of important facilities for each power plant is performed and measures such as aseismic reinforcement are promoted to avoid long-term stoppages due to collapse and damages. In addition, if new knowledge such as the announcement of a newly predicted earthquake is obtained, necessary measures will be investigated after verifying the current seismic countermeasures.

[Main Facilities with Aseismic Reinforcement]

  • stack
  • HRSG (Heat Recovery Steam Generator) Support Structure
  • LNG Carburetor Structure and LNG Pipe Bridge
  • Switchyard* Building
  • *Opening/closing of electric circuit paths by a switchgear such as a circuit breaker installed in a power station
Individual Countermeasures
Individual Countermeasures

Approach to Safety