Countermeasures for Water Leakage

Measures to prevent contaminated groundwater from spreading to the surrounding environment

July 16, 2013

In April 2013, we established a review team to investigate the fact that cesium density has not decreased to below acceptable levels at certain places inside the port of Fukushima Daiichi, and discuss measures to rectify the situation.

When the team investigated the seaside area, high levels of tritium (0.5 million Bq/L) and strontium (1,000 Bq/L) were detected in the groundwater sampled in May, at the east side of Units 1-4 of Fukushima Daiichi NPS. We are assuming that contaminated water, leaked at the time of the accident, has remained and has been diffusing in nearby ground (previously posted).

Since then, we have been fixing the surrounding soil using chemicals (Silica sol) to prevent the water from spreading to the surrounding environment. This work will be conducted through July. We are also digging holes in the surrounding ground to take samplings of groundwater for further investigation.

There have been no significant changes in the nuclide density of the nearby seawater so far. However, we are strengthening monitoring of the seawater inside the port of Fukushima Daiichi.