Out flow of fluid containing radioactive materials to the ocean from areas near intake canal of Fukushima Daiichi Nuclear Power Station Unit 2
Press Release May 03, 2011
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.
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.
(Previously announced)
On May 2nd, 2011, we conducted 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.
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* pit: a vertical shaft made of concrete
TEPCO - Tokyo Electric Power Company, press release