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 out flowing 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. For 
the sake of completeness, we put further reinforcement for the stoppage of 
leakage and consider countermeasures including continuous injection of 
coagulant. We also note the water level of turbine building of Unit 2 
remains unchanged. We will further investigate if there is any other 
leakage.

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 being given warning from Nuclear and Industrial 
Safety Agency (NISA) on April 1st.

From 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 at 
the outside of 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.
(Already announced)

On April 21st, 2011, we collected samples from the water in the pit and 
the seawater in front of the bar screen near the pit. As a result of 
nuclide analyses, radioactive materials were detected as described in 
the attachment. Accordingly, we have reported the result of the analysis 
to NISA and the government of Fukushima Prefecture.

* pit: a vertical shaft made of concrete 

Appendix: 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 12.5KB) 
Appendix: Radioactivity density of seawater(PDF 41.5KB)