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. (We stopped 1 point 
15km off the shore and 3 points 30km off the shore since September 9.)

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.

We have conducted an action to lower a detection limit level of the 
radioactivity concentration and extended the analysis time from October 24, 
so we will be reported the data of sampling analysis at offshore points on 
the day after next of the collected day.
                                                    (Previously announced)

On November 25, 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.

As for the sampling of offshore at 2 points, we extended the analysis time 
and analyzed it again in order to lower a detection limit level. The 
result is shown in the attachment.

Further, the sampling of offshore at 4 points which was planned yesterday 
was changed at 3 points due to bad weather conditions

We reported the above results to NISA as well as to the government of 
Fukushima Prefecture today.

We will continuously conduct the same sampling surveys. 

 
attachment1: Nuclide Analysis Results of Seawater (PDF 13.1KB)  
attachment2: Radioactivity Density of Seawater (PDF 47.6KB)