Kansai Electric Power -power with heart-

Nuclear Power Information
Measures against Potential Tsunami

Countermeasures against Tsunami and Flooding

The Kansai Electric Power is making utmost efforts to enhance the safety and reliability of its nuclear power stations against tsunami by installing tide embankments and protective walls, in order to prevent the recurrence of a severe accident like that at Fukushima Daiichi, which was caused by a massive tsunami.

Breakwater, Tide Embankment and Protective Gates to Mitigate
Tsunami Impact and Prevent Tsunami Flooding of the Site

We have installed a breakwater and tide embankment to protect against tsunami. The offshore breakwater would mitigate the impact of a tsunami, while the tide embankment and protective gates are designed to prevent a tsunami from flooding the site.

1. Installation of Tide Embankment at Mihama Power Station
We installed a 11.5m high (above sea level) and approx. 100m long tide embankment outside Wakasa Bay, which could be directly reached by a tsunami. In addition, in order to protect against flooding due to tsunami flowing into the inland sea, we are installing a 6m high (above sea level; approx. 2.5m actual height) and 1.4km long tide embankment in Nyu Bay.
Tide embankment outside Wakasa bay (11.5m high)
Tide Embankment outside Wakasa Bay (Cross Section)
2. Increasing the Height of the Breakwater at Ohi Power Station
We increased the height of the existing 5m high breakwater to 8m above sea level by placing concrete, installing wave dissipating blocks, and performing reinforcing work.
Increased height of existing breakwater (from 5m to 8m high)
Completed breakwater
3. Installation of Protective Gates at Takahama Power Station
We installed a 8.5m high protective gate on the side of the water intake channel. This gate can be remotely closed in the event of a tsunami to prevent it from reaching and flooding the area. We also installed a 8m high tide embankment on the side of water discharge.
Protective gate on the water intake channel (8.5m above sea level)
Protective Walls which Protect the Site and Plant Facilities

In preparation for an unexpectedly large tsunami that exceeds the height of the tide embankment and other measures, protective walls are installed to prevent the tsunami from flooding into the water intake structure.

Protective walls surrounding seawater pumps

Watertight Doors which Protect Important Safety Components
We replaced the doors of a building which contains important safety components, such as emergency diesel generators, with watertight doors to prevent the building from being inundated in the event of a tsunami. The watertight door is at least 10cm thick and has a robust, waterproof structure.
Watertight door