On 25 March 2014, Japan provided the IAEA with an update to current information on radioactivity in seawater at TEPCO's Fukushima Daiichi Nuclear Power Station (NPS).
The update shows that the concentrations of all radionuclides (i.e. Cs-134, Cs-137, total Beta and H-3) were relatively stable from 16 to 22 March 2014 at sampling point T-2-1, as well as those of total Beta and H-3 at the sampling point T-1 in the same period. Those of Cs-134 and Cs-137 at the sampling point T-1 indicated a temporary elevation (on 16 and 17 March), and on the following days, they returned to the same low level as reported in previous updates disseminated so far.
These sampling points near Fukushima NPS are sentinels to assess effects on the environment by incidents including a leakage of contaminated water by incidents including a leakage of contaminated water.
The NRA also provided an update on the sea area monitoring results for radioactivity obtained from sea water samples taken at a distance of two to 200 kilometres from TEPCO's Fukushima Daiichi NPS.