Tsunami projections for nuclear plant to be redone
The operator of a nuclear power plant in central Japan has been found to have miscalculated the simulated maximum height of a tsunami that could hit the complex.
The Nuclear Regulation Authority once approved tsunami projections submitted by Kansai Electric Power Company for the now-offline Takahama plant in Fukui Prefecture.
The estimates include tsunami heights and tremor intensity associated with earthquakes of the largest conceivable magnitude in the area.
The authority is now examining an application from Kansai Electric to restart the No.3 and No.4 reactors at the plant.
But at a screening meeting on Thursday, Kansai Electric was found to have incorrectly entered data involving the expected duration of a continuous undersea landslide that could happen in the event of a major quake. The cause of the error is unknown.
The utility now needs to use correct data to recalculate the predicted height of the tsunami.
The authority discovered tsunami projections for the Takahama plant to be inadequate immediately after screening began in July of last year.
Kansai Electric later raised its maximum tsunami estimate to 5.7 meters, up about 3 meters from the initial simulation. The company is currently building a 6.5-meter wall to safeguard the plant against tsunami.
Observers say the result of the recalculation might force Kansai Electric to increase its maximum tsunami projection again and overhaul its countermeasures. The process, if necessary, could delay the authority's screening and completion of a tsunami wall.
Kansai Electric officials say they want to review the tsunami estimates and report the results as soon as possible.
All the nuclear reactors in Japan are currently offline. In July of this year, the authority approved a draft safety plan for restarting reactors at the Sendai nuclear plant in Kagoshima Prefecture, Kyushu, southwestern Japan.