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 9.)
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 analysis time from October 24,
so we will be reported the data of sampling analysis at offshore points on
the day after next of the collected day.
(Previously announced)
On October 31 and November 1, 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.
The sampling of seven points offshore that was scheduled on October 31 was
suspended due to bad weather conditions.
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 17.8KB)
attachment2: Radioactivity Density of Seawater (PDF 33.6KB)