Japan has announced its contentious strategy on how it plans to release contaminated water from the Fukushima nuclear power plant. James Murray analyses how the country will dispose of the water and provides an insight into the mixed reactions from various stakeholders to the news.


On 11 March 2011, an earthquake with a 9.1 magnitude struck off the coast of Japan in the Oshika Peninsula.

It was the most powerful earthquake ever recorded in the East Asian country and it triggered giant tsunami waves that are reported to have reached heights of up to more than 38 metres.

Often referred to as the Great East Japan Earthquake, it left a devasting death toll – believed to be just short of 20,000 people – in its wake and crippled large parts of north-eastern Japan, with the Japanese government estimating up to $199bn worth of damage was caused.

But the disastrous impact it had on the Fukushima Daiichi Nuclear Power Plant in Okuma, Fukushima Prefecture, is one of the most long-lasting consequences of the seismic event.

It caused three of the site’s reactors to reach a level 7 meltdown, which comes as a result of core damage from overheating. Regarded as the worst nuclear disaster since Chernobyl in 1986, the Fukushima plant spewed radioactive water into the Pacific Ocean and across Fukushima, forcing up to 154,000 residents to evacuate their homes.

It has also resulted in years of clean-up efforts, with decades worth of work currently ongoing to decommission the site.

According to the Japanese government, nearly 1.3 million tonnes of contaminated water, or enough to fill about 500 Olympic-sized swimming pools, is stored in 1000 large tanks at the plant – costing about 100bn Japanese yen ($913m) a year – and space is set to run out in the summer of 2022.

That has forced officials in Tokyo, alongside plant operator Tokyo Electric Power (Tepco), to formulate a plan on how to dispose of the contaminated water to free up space.


Government’s plans to release contaminated water from Fukushima

Japan’s Ministry for Economy, Trade and Industry (METI) released a basic policy on 13 April, announcing that the water will be released into the Pacific Ocean, using an extensive pumping and filtration system, which extracts tonnes of newly contaminated water each day and filters out most radioactive elements.

“Regarding the tanks installed on the site of Fukushima Daiichi nuclear power plant, it has been pointed out that the existence of the tanks themselves is a cause of the adverse impacts on reputation, and that the risk of leakage and other risks due to deterioration or disaster may increase along with long-term storage,” the document said.

“Moreover, building additional tanks in surrounding areas outside the Fukushima Daiichi plant for additional storage would require more land and result in an additional burden on the people who are working diligently towards reconstruction.”

Prime Minister Yoshihide Suga told Jiji Press that the disposal of the treated water is an “unavoidable challenge for the decommissioning of the plant”. “The government concluded that the ocean release is a realistic method,” he added.


The technology and IAEA support

The volume of the contaminated water is continuing to build up at the site because water is still being injected into the plant to cool the fuel debris, while rain and groundwater have also seeped into the facility.

First disposals of the water are expected to begin in two years, giving Tepco time to treat the wastewater ready for disposal, with the process expected to take decades to complete.

The filtration system, known as Alps (advanced liquid processing system), will be able to significantly dilute most of the radioactive material in the water, although there is no way to fully remove traces of tritium, a rare and radioactive isotope of hydrogen.

The Japanese government has said the dilution would reduce tritium levels to “well below” standards set domestically and by the World Health Organization for drinking water.

Fukushima contaminated water plans
First disposals of the water are expected to begin in two years, giving Tepco time to treat the wastewater ready for disposal, with the process expected to take decades to complete (Credit: Flickr/UCLA Newsroom)

The plans have been welcomed by the International Atomic Energy Agency (IAEA), with its director general Rafael Mariano Grossi stating that the agency stands ready to provide technical support in monitoring and reviewing the strategy’s safe and transparent implementation.

The IAEA claims the plans are “both technically feasible and in line with international practice”, adding that controlled water discharges into the sea are routinely used by other nuclear power plants.

But it admits that the large amount of water stored at Fukushima “makes it a unique and complex case”.

Grossi said the decision by the government is a “milestone that will help pave the way for continued progress in the decommissioning of the Fukushima Daiichi nuclear power plant”.

“Tanks with the water occupy large areas of the site, and water management, including the disposal of the treated water in a safe and transparent manner involving all stakeholders, is of key importance for the sustainability of these decommissioning activities,” he added.

The IAEA director general said his agency will work closely with Japan “before, during and after the discharge of the water”. “Our cooperation and our presence will help build confidence – in Japan and beyond – that the water disposal is carried out without an adverse impact on human health and the environment,” he added.


What are the alternative options?

Alongside releasing the contaminated water into the sea, four other options were examined by a panel from METI on the best way to dispose of the water.

A geosphere injection, which would have involved tritiated water being injected into deep geosphere layers – about 2,500m deep – through an underground pipeline, was one of the first methods explored.

Another proposal was a vapour release, where the water would go through evaporation processing, and a vapour containing tritium would be sent to evaporation equipment to be released from an exhaust pipe into the atmosphere as a high-temperature vapour.

A further suggestion was a hydrogen release. This involved reducing the water to hydrogen by means of electrolysis, before then being released into the atmosphere.

The final option was an underground burial, which would have seen the water mixed with a cement-based solidifying agent and then buried within the confines of a concrete pit.

But the panel deemed that an underground burial or a geosphere injection would require formulating new regulations, and concerns were made around finding an appropriate site for the proposals.

The hydrogen option would have required substantial funding and further technological developments at the site, while the vapour release proposal was rebuffed because establishing monitoring methods may have proved difficult.

Greenpeace Japan commissioned consulting engineer Satoshi Sato to write an in-depth report on the decommissioning plans for Fukushima.

He believes that the cooling strategy at the site should be changed from water cooling to air cooling to stop more water from building up around the fuel debris.

Sato suggests the best method for dealing with the contaminated water would be to opt for a “Dry Island” concept, where a 7km long moat, deeper than seawater level, is dug around the entire site to prevent groundwater from reaching the reactors – allowing time for new technologies to be developed to eliminate all the nuclides in the water.

Analysis in The Korea Times by environmental lawyer Duncan Currie and Shaun Burnie, a nuclear specialist with Greenpeace, claims Japan’s plans to release the water into the sea goes against international law and offers up a similar solution to Sato.

They say a clear alternative is to securely store the water in robust tanks for the long term over hundreds of years, allowing the best available technology to be applied for further processing to remove all the radionuclides.


Why has Japan’s plans to remove the Fukushima contaminated water proved controversial?

While Japan’s decision to dispose of the water into the Pacific Ocean was met with support by the IAEA, its plans have proved controversial amongst the Fukushima community, neighbouring countries, and human rights and environmental groups.

Greenpeace International’s executive director Jennifer Morgan said that in the 21st century, when the planet and in particular the world’s oceans are “facing so many challenges and threats”, it is an “outrage that the Japanese government and Tepco think they can justify the deliberate dumping of nuclear waste into the Pacific Ocean”.

She added that the decision is a violation of Japan’s legal obligations under the United Nations Convention on the Law of the Sea (UNCLOS), and believes it will be “strongly resisted over the coming months”.


Impact on the food chain

A Greenpeace report by Shaun Burnie in 2020 warned that the disposing of the contaminated water into the sea would release hazardous radionuclides such as strontium-90 and carbon-14 amongst others.

The analysis claims that carbon-14, which has a half-life of 5,730 years, could cause potential damage to human DNA and warns that once it is introduced into the environment, the radioactive isotope will be delivered to local, regional and global populations for many generations.

Fukushima contaminated water plans
Japan’s national federation of fisheries cooperatives strongly oppose the government’s plans (Credit: Shutterstock/DoublePHOTO studio)

But speaking to the Guardian, Geraldine Thomas, chair of molecular pathology at Imperial College London, said carbon-14 was not a health risk, arguing that chemical contaminants in seawater like mercury should concern consumers more “than anything that comes from the Fukushima site”. On eating Fukushima seafood, “I would have no hesitation whatsoever,” she added.

That is not how large quarters of the Fukushima community and JF Zengyoren, Japan’s national federation of fisheries cooperatives, who strongly oppose the government’s plans, feel about the situation, though.

At a meeting in October 2020, JF Zengyoren chairman Hiroshi Kishi warned that if the contaminated water was released into the sea “all the efforts of fishing industry workers to date would come to nothing”.

“It would be a setback and let down for those in the fishing industry and could have a devastating impact into the future,” he added. “Not releasing it into the sea is simply the best approach.”


Impact on the Fukushima community and human rights

Kazue Suzuki, a climate and energy campaigner at Greenpeace Japan said the Japanese government has “once again failed the people of Fukushima”.

“The government has taken the wholly unjustified decision to deliberately contaminate the Pacific Ocean with radioactive wastes,” he added. “It has discounted the radiation risks and turned its back on the clear evidence that sufficient storage capacity is available on the nuclear site as well as in surrounding districts.”

Suzuki said that instead of using the best available technology to minimise radiation hazards by storing and processing the water over the long term, the government has “opted for the cheapest option”.

“The Cabinet’s decision failed to protect the environment and neglected the large-scale opposition and concerns of the local Fukushima residents, as well as the neighbouring citizens around Japan,” he added. “Greenpeace stands with the people of Fukushima, including fishing communities, in their efforts to stop these plans.”

Independent experts from the UN’s Office of the High Commissioner for Human Rights (UN Human Rights) have said the contaminated water at the nuclear plant poses “major environmental and human rights risks” and that any decision to discharge it into the Pacific Ocean “cannot be an acceptable solution”.

The group said discharging contaminated water into the sea would be a “failure to uphold human rights”, including the human rights of children by “exposing them to further risks inside and outside Japan”.

“We recall that Japan has a continuing duty to prevent safety risks and exposure, especially the exposure of children and other vulnerable groups to radiation,” added the UN experts.

“Children are more sensitive to radiation and are at higher risk of radiation-related cancers of certain tissues. They are also more likely to experience higher external and internal radiation exposure levels than adults.”

The experts have called upon Japanese authorities to intensify their efforts at preventing risks, protecting the affected population, including children from adverse effects of radiation exposure, in accordance with their international human rights obligations.


Fierce response from neighbouring countries

While the US state department released a statement saying Japan has been “transparent” about its decision, and “appears to have adopted an approach in accordance with globally accepted nuclear safety standards”, the decision has not gone down as well with neighbouring nations China and South Korea.

Zhao Lijian, a spokesman for China’s foreign ministry, said the country “expresses grave concern” over the plans to release the contaminated water into the sea.

“The wastewater from Fukushima after the highest-level nuclear accident is entirely different from the wastewater from normal operations of nuclear power plants,” he added.

Lijian warned that the radioactive materials from the site could “spread to most of the Pacific Ocean within 57 days from the date of discharge, and reach all oceans in a decade”.

“The level of radioactive isotope carbon-14 in the wastewater will remain hazardous for thousands of years and may cause genetic damage,” he added.

“Japan should respond with honesty to views from authoritative institutions and experts. Still, less should it disregard global public interests and simply dump contaminated water from Fukushima into the sea and be done with it.”