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 - Pacific
Ocean 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 (twice a day at
two points out of such four points since March 26).
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, 9
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 (Regarding 6 points out of 9 points of 3km off the
shore, from May 9, we conduct sampling at the lower layer in addition to
upper layer. We conduct sampling for those 6 points twice a week).
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 May 25, 2011, we conducted sampling to evaluate the spread of
radioactive materials to the ocean which were detected at Fukushima
Daiichi Nuclear Power Station. Since the radioactive materials were
detected as shown in the attachment, today, we informed NISA and the
government of Fukushima Prefecture of the results.
Due to the bad weather condition, we postponed the sampling in 11
off-coast locations yesterday.
Also, as a result of the analysis regarding plutonium 238, 239 and 240 in
seawater on the samples corrected on May 9th, we did not detect any of
these.
We will continuously conduct the similar sampling.
attachment1: Results of Nuclide Analysis of Seawater(PDF 54.4KB)
attachment2: Fukushima Daiichi Nuclear Power Station: Plutonium analysis
result in seawater(PDF 7.20KB)
attachment3: Radioactivity Density of Seawater(PDF 50.4KB)