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 10, 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 not detected
as shown in the attachment.
On September 10, 2011, in order to observe effect on surroundings caused of
implementation of water seal work at the southern part of Unit 1 to 4 open
water channel, we are conducting additional samplings around south
discharge channel.
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 15.2KB)
attachment2: Radioactivity Density of Seawater (PDF 33.2KB)
