At around 9:30 am on April 2nd, 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 outflowing to the ocean. At around 12:20 pm on April 
2nd, we reaffirmed the event at the scene.
We have implemented sampling of the water in the pit, together with the 
seawater in front of the bar screen near the pit. These samples were sent 
to Fukushima Daini Nuclear Power Station for analyses.

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

Since April 5th we have been conducting sampling surveys of the water in 
the pit 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. As for 
other nuclides, we will revaluate in accordance with the preventive 
measures formulated after receiving a warning from Nuclear and Industrial 
Safety Agency (NISA) on April 1st.

On April 12th, 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 17th, 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.

Apart from the daily sampling surveys, we have conducted the sampling 
survey of the water in the upper and lower layer of the ocean inside the 
silt fence in front of the bar screen of Unit 2 since May 5th. 
                                                    (Previously announced)

On May 6th, 2011, we conducted the sampling survey of the water in the pit 
and the seawater in front of the bar screen near the pit, and conducted 
nuclide analysis of radioactive materials in the water. As a result, some 
radioactive materials were detected as described in the exhibit. 
Accordingly, we have reported the result of the analysis to NISA and the 
government of Fukushima Prefecture.

We will continue to conduct the same kind of sampling surveys.

* pit: a vertical shaft made of concrete 

Appendix1:Result of Nuclide Analysis of the seawater at the shallow draft 
          quay, Unit 2 screen, and the water intake canal of Unit 1-4 
                                                              (PDF 54.8KB) 
Appendix2:Radioactivity density of seawater (PDF 26.2KB)