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 1.)

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 time for analysis from October 
24, so we will report the data of sampling analysis at offshore points on 
the day after next of the collected day.
                                                    (Previously announced)

On December 20 and 21, 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.

In addition, On December 20, 2011, we conducted sampling at 5 points 
within 15km off the shore of Fukushima Daiichi Nuclear Power Station by 
unmanned research vessel, and evaluated the spread of radioactive 
materials. These analysis results were also shown in the attachment.

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 20.2KB) 
attachment2: Radioactivity Density of Seawater (PDF 50.8KB)