On March 28 2011, we were advised from Nuclear Safety Commission of Japan 
to enhance sampling surveys regarding water accumulated in underground
floor of the turbine buildings of Fukushima Daiichi Nuclear Power Station.
In order to verify any leakages to underground and sea, and safety, we
have been implementing the sampling surveys of subsurface water and
seawater.

Regarding sampling surveys of sub-drains, based on the instruction from
Nuclear and Industry Safety Agency (NISA) on April 14th, we will continue
conducting the same kind of sampling surveys three times a week, and
inform the result on the next day of the survey.
                                                    (Previously announced)

On June 13, 2011, we conducted sampling surveys regarding sub-drains
(subsurface water obtained and managed in the site) near the turbine
buildings of Fukushima Daiichi Nuclear Power Station. Today, we reported
to NISA and the government of Fukushima Prefecture, since, as the results
of nuclide analyses, radioactive materials were detected as shown in the
attachment. 

 
Appendix1: Results of Nuclide Analyses of Sub-drains (PDF 10.6KB) 
Appendix2: Radioactivity Density of Sub-drain (PDF 44.9KB)