TEPCO : Press Release | Out flow of fluid containing radioactive materials to the ocean from areas near intake canal of Fukushima Daiichi Nuclear Power Station Unit 2 (continued report 12)

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Press Release (Apr 16,2011)
Out flow of fluid containing radioactive materials to the ocean from areas near intake canal of Fukushima Daiichi Nuclear Power Station Unit 2 (continued report 12)

 
At around 9:30 am on April 2nd, 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. 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 analysis.

At around 5:38 am on April 6th, we have observed stoppage of spilling of 
water 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 countermeasure including continuous injection of coagulant. We 
will also note the water level of turbine building of unit 2 remain 
unchanged. We will further investigate if there is any other leakage.

Since April 5th we have been conducting sampling of seawater in the pit 
and in front of the bar screen near the pit. Regarding the results on 
three nuclides (iodine 131, cesium 134, cesium 137), we report those as 
definite result. 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, with the installation of the silt fence, we changed the 
sampling points from the front of the bar screen, Unit 4 to inside of the 
water intake for Units 1 to 4, north side and south side.
(Already announced)

On April 15th, 2011, we collected samples from seawater in the pit and in 
front of the bar screen near the pit. As a result of the nuclide analysis, 
radioactive materials were detected as described in the attachment. 
Accordingly, we have reported the result of the analysis to NISA and 
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 11.1KB) 
Appendix: Radioactivity density of seawater(PDF 17.6KB)