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 August 15, 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. 
Yesterday, we implemented closure work using steel pile sheet piles at the
southern side of intake channel's open conduits of Unit 1 to 4. In order
to monitor its influence to the circumstances due to the work, we
increased the sampling around the southern discharge channel in frequency.
Also we analyzed Tritium, total alpha, and total beta rays in the seawater
sampled on July 11 and 14, and as a result, total beta rays were detected
as described in the attachment. 
 
We informed NISA and the government of Fukushima Prefecture of the results
today. 
We conducted sampling on 2 locations out of planned 8 locations due to the
weather. 
 
We will continuously conduct the similar sampling. 

attachment1: Results of Nuclide Analysis of Seawater (PDF 55.0KB) 
attachment2: Results of Nuclide Analysis of Seawater <Offshore> (PDF 39.5KB) 
attachment3: Radioactivity Density of Seawater (PDF 27.5KB)