Japan's Nuclear Regulation Authority on Wednesday endorsed a plan to discharge treated water stored at the crippled Fukushima Daiichi nuclear power plant into the sea.
The plan to release treated water, expected to start around next spring, will be officially approved in July at the earliest after the regulator hears submissions from the public, according to NRA Chairman Toyoshi Fuketa.
In a meeting in Tokyo Wednesday, Japan's Economy, Trade and Industry Minister Koichi Hagiuda thanked visiting International Atomic Energy Agency Director General Rafael Grossi for his leadership in leading the IAEA's review on the planned water discharge, saying the release of a report last month was "a major step forward" toward executing the discharge plan in a safe manner.
In late April, the IAEA task force released its first evaluation report on the technical preparations for the discharge, saying the plan is so far making good progress but needed further improvement.
Grossi was quoted by the ministry as saying that the IAEA review will assure people around the world that water, treated through an advanced liquid processing system that removes radionuclides except for tritium, will not have a harmful impact on public health and environment.
Grossi is scheduled on Thursday to inspect the Fukushima plant, damaged by the 2011 earthquake and tsunami, to enhance transparency of the discharge plan and gain international understanding amid worries and opposition expressed by China and South Korea, as well as fishing communities in Japan.
Seoul will now take part in an IAEA-led monitoring of the planned discharge, according to a South Korean Foreign Ministry official.
The plant operator, Tokyo Electric Power Company Holdings Inc., will need to gain consent from municipalities hosting the power complex to start construction of the water discharge facilities.
The water will be diluted with seawater to one-40th of the concentration permitted under Japanese safety standards and released 1 kilometer off the power plant via an underwater pipeline, according to the plan.
After the 2011 nuclear accident triggered by a massive earthquake and tsunami, water that has become contaminated after being pumped in to cool melted reactor fuel has been accumulating at the complex, also mixing with rainwater and groundwater at the site.
TEPCO applied for an evaluation of the plan by the NRA in December. Through a total of 13 review meetings, the watchdog evaluated the function of the diluting facility, as well as a method of suspending the discharge of treated water when an unusual situation is detected, and measures against earthquakes and tsunami, among others.
The NRA concluded the water discharge will help the operator secure space for facilities needed for future decommissioning work and lower overall risks to the Fukushima plant.
Fuketa also asked TEPCO to ensure there are no incidents at the planned water discharge facilities, given that the treated water has to travel quite a distance before discharge.
Yoshihiro Murai, the governor of Miyagi Prefecture adjacent to Fukushima Prefecture, said he will continue to urge TEPCO and the central government to explore alternatives to releasing treated water into the sea.