The government of Japan briefed foreign embassy officials 3 February on an increasingly preferred method of disposal of treated radioactive water from the crippled Fukushima nuclear power plant into the ocean. 28 diplomats representing 23 countries are reported to have attended the meeting.
The proposal to release up to 1 million tons of treated, but still contaminated, water into the ocean is based on an expert panel’s finding that ocean release is preferable to other methods as remaining radiation levels could be monitored better.
The ministry of Economy, Trade, and Industry has contemplated boiling the water and releasing it as steam or dumping it into the ocean and called both methods “realistic options”. There are precedents both in Japan and elsewhere for each method.
While the proposal is non-binding and there is no set deadline for decision, there is pressure to come to a conclusion. Any decision will involve further consultation with local farmers and fishermen and neighbouring countries but no decision is expected prior to the beginning of the Olympics this summer.
The radioactive water has already been treated using an advanced liquid processing system and has been stored in tanks on the Tokyo Electric Power Co (TEPCO) site. Treated water, which still contains trace amounts of tritium, is accumulating at an estimated rate of between 150 to 175 tons per day. Storage capacity will be expanded through the end of 2020 but the facilities are expected to reach full capacity by 2022. There is no plan for further expansion of these facilities beyond the end of 2020.
In the past, TEPCO has released small amounts of treated contaminated water into the ocean and such release method is viewed to have “more certainty” as monitoring radiation levels is easier.
The ministry claimed that health effects of either approach would be minimal: between 0.052 and 0.62 microsievert annually for a discharge into the ocean, and 1.3 microsieverts if released into the atmosphere.
The International Atomic Energy Agency has argued that properly filtered water could be diluted with seawater and then safely released into the ocean without causing environmental problems. Indeed, nuclear reactors have used the water disposal method.
However, neighbouring countries, local farmers and fishermen, and environmental activists are not necessarily convinced. Some claim that consumers will object to purchasing local food and seafood that will have been exposed to the radioactive water. Others claim that any release is “irresponsible” and that the contaminated water should be further treated and buried.