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)

As a result of Nuclide analysis from the sample regarding sub-drains 
(subsurface water obtained and managed in the site) near the turbine 
buildings of Fukushima Daiichi Nuclear Power Station collected on July 6, 
radioactive materials were detected as shown in the attachment and today, 
we reported to NISA and the government of Fukushima Prefecture. 

We also conducted analyses of plutonium in the subsurface water on June 13, 
2011. As a result, plutonium was not detected as shown in the Appendix. 

Appendix1: Results of Nuclide Analyses of Sub-drains (PDF 10.5KB) 
Appendix2: Result of Plutonium analysis on Sub-drain water at Fukushima 
           Daiichi nuclear power plant (PDF 7.80KB) 
Appendix3: Radioactivity Density of Sub-drain (PDF 24.6KB)