On 4 December 2013, the Nuclear Regulation Authority (NRA) of Japan provided the IAEA with an update on radioactivity in seawater at TEPCO's Fukushima Daiichi Nuclear Power Station (NPS).
This update states that the concentrations of Cs-134, Cs-137, total Beta and H-3 were relatively stable from 25 November to 1 December 2013 at the Nuclear Power Station.
In addition, the NRA provided an update on the monitoring report of sea area radioactivity obtained from samples taken in the vicinity of TEPCO's Fukushima Daiichi NPS and in the open sea.