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 23, 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. 

We informed NISA and the government of Fukushima Prefecture of the results 
today. 

We will continuously conduct similar samplings. 

 
attachment1: Nuclide Analysis Results of Seawater (PDF 10.6KB)  
attachment2: Radioactivity Density of Seawater (PDF 17.3KB)