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 December 2, 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 15 November 2011 we have increased sampling points to evaluate the 
effect of the cleaning work to the surrounding environment, conducted at 
the bottom part of the reserved intake pumps of Unit 5 and 6 in order to 
maintain the performance level of the pumps. We will report these results 
as well.

We analyzed tritium, total alpha rays and total beta rays contained in the 
sea water sampled on November 14, 2011. As a result, we have detected 
tritium and total alpha rays as shown in the attachment.

We reported the above results to NISA as well as to the government of 
Fukushima Prefecture today.

We will continuously conduct the same sampling surveys.

*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 32.6KB) 
Appendix2: Nuclide Analysis Results of Radioactive Materials in Seawater 
           Fukushima Daiichi Nuclear Power Station; Inside the water 
           intake canal of Units 5 and Unit 6 (PDF 10.8KB) 
Appendix3: Nuclide Analysis Results of Radioactive Materials in Seawater 
           inside Water Intake Canal of Units 1 - 4 at Fukushima Daiichi 
                                                              (PDF 10.8KB) 
Appendix4: Radioactivity Density of Seawater (PDF 43.3KB)