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

We collected samples from sub-drains (subsurface water obtained and 
managed in the site) near the turbine buildings of Fukushima Daiichi 
Nuclear Power Station on November 18, and conducted nuclide analysis. As 
a result, radioactive materials were detected as shown in the appendix. 

We analyzed tritium ,total α and total β contained in the water of 
sub-drains, which was sampled on Oct 10. As a result, tritium and total β 
were detected as shown in the appendix. 

Today, we reported the results to NISA and the government of Fukushima 
Prefecture. 

Appendix1: Result of nuclide analysis of sub drain of Fukushima Daiichi 
                                                       NPS (PDF 10.5KB) 
Appendix2: Result of nuclide analysis of sub drain of Fukushima Daiichi 
                        NPS(Date of sampling Oct 10, 2011) (PDF 81.9KB) 
Appendix3: Radioactivity Density of Seawater (PDF 21.9KB)