On 11 June 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 highlights two reports submitted by TEPCO to the NRA regarding water leaks from top notch tanks to the dike surrounding these tanks at the Fukushima Daiichi NPS. The first TEPCO report on 2 June 2014 states that it stopped the water leaks from the top notch tanks and transferred 4 cubic metre of water remaining in a dike to another tank. The second TEPCO report, on 9 June 2014, states that the amount of water leaked from the two top notch tanks through the dike to the ground surface was estimated to be approximately 3.4 cubic metres at most.
Taking into account all information related to the water leaks thus far, the NRA considers the effects of water leaks to the sea area are unlikely to appear.
The NRA also provided an update on sea area monitoring results for radioactivity obtained from sea water samples taken at a distance of 2 to 200 kilometres from TEPCO's Fukushima Daiichi NPS.