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 September 9, 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 appendix. 

From July 12, 2011, in order to enhance the prevention of leakage and 
dispersion of water containing high level of radioactive substances, we are 
installing a steel sheet-pile wall at the south side of open canal, water 
intake for Units 1 to 4. In order to monitor the influence of this work, we 
shortened the interval and increased the points for sampling.

We informed Nuclear and Industrial Safety Agency (NISA) and the government 
of Fukushima Prefecture of the results above today.

We will continue to conduct same kind of samplings.

* Pit: 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 14.9KB) 
Appendix2: Radioactivity Density of Seawater (PDF 44.7KB)