At around 9:30 am on April 2, 2011, we detected water containing radiation 
dose over 1,000 mSv/h in the pit* where power supply cables are stored near
the intake channel of Unit 2. Furthermore, there was a crack of about 20 cm
length on the concrete lateral of the pit, from where the water in the pit 
was flowing out to the ocean. At around 12:20 pm on April 2, we reaffirmed 
the event at the scene. 
We have implemented sampling of the water in the pit of Unit 2, together 
with the seawater in front of the bar screen near the pit of Unit 2. These 
samples were sent to Fukushima Daini Nuclear Power Station for analyses.

At around 5:38 am on April 6, we observed stoppage of spilling of water to 
the ocean from the crack on the concrete lateral of the pit. 

Since April 5, we have been conducting sampling surveys of the water in the
pit of Unit 2 and the seawater in front of the bar screen near the pit. 
Regarding the survey results of the detection of three nuclides (iodine 131,
cesium 134, cesium 137), we report those as definite results, and for the 
other nuclides, we will re-evaluate them.

On April 12, due to the installation of silt fences, we changed the 
sampling points from the front of the bar screen of Unit 4 to the north and
the south of the inside of the water intake canal of Units 1 to 4. Since 
April 17, we have been conducting an additional sampling survey outside the
silt fence in front of the bar screen of Unit 2, in order to assess the 
effect of the installation of the silt fence.

On May 11, 2011, responding to out-flow leakage of contaminated water from 
the intake canal of Unit 3, from May 12th, we additionally conducted the 
sampling of the seawater inside and outside of the silt fence in front of 
the bar screen near the pit of Unit 1, 3 and 4. 
                                                     (Previously announced)

On August 17, 2011, we conducted sampling of the seawater near the intake 
canal of Units 1 to 4 of Fukushima Daiichi Nuclear Power Station and 
analyzed the samples. As a result, some radioactive materials were detected
as described in the attachment. 

Therefore, we informed Nuclear and Industrial Safety Agency (NISA) and the 
government of Fukushima Prefecture of the results above.

We will continue to conduct the same kind of sampling.

* Pit: a vertical shaft made of concrete 

Appendix1: Nuclide Analysis Results of Radioactive Materials in Seawater 
           Fukushima Daiichi Nuclear Power Station; the shallow draft quay, 
           Unit 1-4 screen, and the water intake canal of Units 1-4 
                                                              (PDF 18.3KB) 
Appendix2: Radioactivity Density of Seawater (PDF 48.5KB)