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 14, 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 conducted an analysis about plutonium in the sea water which was
collected on August 27. As a result, plutonium was not detected as
described in the appendix.
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 12.8KB)
attachment2: Pu analysis of seawater at Fukushima Daiichi Nuclear Power
Station (PDF 7.91KB)
attachment3: Radioactivity Density of Seawater (PDF 38.8KB)
