Countermeasures for Water Leakage

The Groundwater Bypass System

June 25, 2013

In order to decrease the amount of groundwa ter, which is flowing into the basement of the reactor/turbine buildings at Fukushim a Daiichi NPS at a pace of approx. 400 tons/day, we are planning to operate the “groundwater bypass system”. The“groundwater bypass system” is a system which pumps up groundwater from the upper stream (mountain side of the reactor buildings, from 35m above sea level), bypassing the reactor/turbine buildings, and deposits it into the ocean, lowering the groundwater level. With this system, the groundwater flowing into the buildings is estimated to be reduced by 100 tons/day.

We began test operation in April 2013, and have been conducting water quality tests. So far, we have confirmed that the level of radioactive materials contained in the pumped up water is far below our control target of 1Bq/L. We would like to start full operation upon obtaining consensus from the stakeholders.