TEPCO to Move Up Measures against Tsunami from Kuril Trench Quake

August 20, 2018

Toyko- Tokyo Electric Power Company Holdings Inc. has decided to move up ongoing measures at its disaster-crippled Fukushima No. 1 nuclear power station against major tsunami from a potential huge earthquake that may occur at the Kuril-Kamchatka Trench in the Pacific.

The company made the decision after the government's earthquake research committee said in a report in December last year that the likelihood of a quake with a magnitude of at least 8.8 occurring at the trench off the coast of the country's northernmost prefecture of Hokkaido within 30 years stands at 7-40 pct.

Such a giant earthquake is highly imminent as about 400 years have passed since the previous quake took place along the trench in the 17th century, it also said.

TEPCO will accelerate measures to prevent radiation-contaminated water accumulated in the basements of some reactor buildings at the power station in Fukushima Prefecture, northeastern Japan, from overflowing in case the plant is hit by tsunami from a Kuril trench quake.

In the event a powerful earthquake occurs at the trench, tsunami of up to 10.1 meters could reach the plant and the areas where reactor buildings are located could be flooded to a point up to 1.8 meters from the ground, according to the company.

If tsunami water comes into damaged reactor buildings through openings such as hatches and staircases, the radiation-tainted water could flow out of part of the basements when the tsunami water recedes, TEPCO said.

The company has finished closing about half of a total of 122 openings.

TEPCO will complete such work in the first half of fiscal 2020 for 11 openings at the No. 2 and No. 3 reactors. The company previously planned to end the work by the March 2021 end of fiscal 2020.

Furthermore, TEPCO will additionally close nine openings at the No. 4 reactor.

All of the six reactors at the Fukushima No. 1 plant, including the No. 1, No. 2 and No. 3 units that were heavily damaged in the March 2011 powerful earthquake and tsunami, are set to be scrapped. Jiji Press