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 5, 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 reported the above results to NISA as well as to the government of
Fukushima Prefecture today.
Due to the weather condition, planned sampling surveys at offshore points
were canceled.
We will continuously conduct the same sampling surveys. 
attachment1: Nuclide Analysis Results of Seawater (PDF 10.8KB)
attachment2: Radioactivity Density of Seawater (PDF 21.4KB)
