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 December 7, and conducted nuclide analysis. As a
result, radioactive materials were detected as shown in the appendix. 

Furthermore, as a result of an analysis on strontium contained in the air
sampled on November 14, strontium 89 and 90 were detected as described 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: Nuclide Analysis Results (Sub Drain)(PDF 10.7KB) 
Appendix3: Radioactivity Density of Sub-drain (PDF 21.8KB)