On March 21, 2011, we conducted sampling, as a part of monitoring of
surrounding environments, and detected radioactive materials in the
seawater around the water discharge canal (of the south side) of
Fukushima Daiichi Nuclear Power Station, which was damaged by the Tohoku-
Taiheiyou-Oki Earthquake. Therefore, we informed Nuclear and Industrial
Safety Agency (NISA) and the government of Fukushima Prefecture of the
results.
Since March 22, we have conducted seawater sampling surveys at four
points off the shore of Fukushima Daiichi Nuclear Power Station.

Since April 17, we have also conducted sampling surveys at four points
(2 points have been added since April 26, another 3 points since April 30,
and another 1 point since May 5, 10 points in total) of 3 km off the
shore of Fukushima Daiichi Nuclear Power Station, two points of 8 km off
the shore of the Power Station and 6 points of 15 km off the shore of the
Power Station and informed them of evaluation results.
Also, we added 2 points each 5 and 30 km off the shore since May 27, and
1 point each 5, 15 and 30 km off the shore since June 2.

The data of three detected nuclides (Iodine-131, Cesium-134 and Cesium-
137) will be reported as fixed data. Other nuclide figures are to be re-
evaluated.
                                                   (Previously announced)

On September 28, 2011, we conducted sampling to evaluate the spread of
radioactive materials to the ocean which were detected at Fukushima
Daiichi Nuclear Power Station. As a result, radioactive materials were
detected as shown in the attachment.

Due to the bad weather condition, we did not conduct the samplings at 7
off-coast locations yesterday.  

Also we analyzed plutonium in the seawater sampled on September 12 and
tritium, total alpha and total beta rays in the seawater sampled on
August 15 and 27, and as a result, they were not detected as described in
the attachment.  

Today, we reported the results to NISA and the government of Fukushima
Prefecture.  

We will continuously conduct the same sampling surveys. 

 
attachment1: Nuclide Analysis Results of Seawater (PDF 14.9KB)  
attachment2: Analysis Results of Pu in Seawater at Fukushima Daiichi Nuclear 
             Power Station (PDF 88.3KB)  
attachment3: Radioactivity Density of Seawater (PDF 28.1KB)