Inside Story

Water, water everywhere

Scientists and Pacific governments are worried by Japan’s plan to dump radioactive wastewater from Fukushima into the Pacific Ocean

Nic Maclellan 20 December 2022 2513 words

No clear answers: workers checking one of the more than 1000 tanks storing radiation-contaminated water from the tsunami-crippled Fukushima nuclear power plant in Okuma. Kimimasa Mayama/EPA

Early next year Japan plans to begin dumping 1.3 million tonnes of treated radioactive wastewater from the Fukushima nuclear reactor into the Pacific Ocean. Fiercely opposed by local fishermen, seaweed farmers and residents near Fukushima, the plan has also been challenged by China, South Korea and other neighbouring states, as well as by the Pacific Islands Forum.

At their annual summit in July, island leaders appointed an independent five-member expert scientific panel to probe the project’s safety. Forum secretary-general Henry Puna, concerned about harm to the fishing industry in Japan and the wider Pacific region, has reinforced regional concern that the scientific data doesn’t justify the plan.

“Experts have advised a deferment to the impending discharge into the Pacific Ocean by Japan is necessary,” Puna said last month. “Based on that advice, our members encourage consideration for options other than discharge, while the independent panel of experts continue to further assess the safety of the discharge in light of the current data gaps.”

In a confidential report to the Pacific Islands Forum, the expert panel outlined detailed concerns about the project, arguing that any decision to proceed should be postponed. Even though Japan’s Nuclear Regulation Authority has given the go-ahead for construction, a growing number of scientists are warning about the long-term implications of dumping more than a million tonnes of water containing radioactive isotopes into the Pacific.

The waste problem goes back to March 2011, when three nuclear reactors at the Fukushima Daiichi nuclear power plant were flooded after an offshore earthquake. A fourteen-metre tsunami hit the coast, causing massive damage to the reactors’ power supply and cooling systems. The partial meltdown of the reactor cores caused extensive damage as fuel rod assemblies burned through steel containment vessels and into the concrete base of the reactor buildings.

For more than a decade, the Tokyo Electric Power Company, known as TEPCO, has been using water to cool the excess heat still emanating from the melted fuel rods. The highly contaminated cooling water is then stored in more than a thousand tanks at the site. With more than a hundred tonnes of water collected every day, storage space is running out.

Japan proposes to dump this wastewater into the Pacific Ocean after passing it through an Advanced Liquid Processing System designed to remove most radioactive materials.

The cost of decommissioning the stricken Fukushima reactors has put TEPCO — and Japanese taxpayers — under massive pressure. Since 2011, more than ¥12 trillion (A$120 billion) has been spent on cleaning up the plant, decontaminating the site and compensating people affected by the accident. This accounts for half of the amount budgeted for work that must continue for many decades.

The Japanese government has already provided ¥10.2 trillion in no-interest loans to TEPCO. Last month Japan’s Board of Audit revealed that repayment of these loans will be delayed, highlighting TEPCO’s ongoing financial crisis.

Many analysts are concerned TEPCO is looking at ocean waste dumping as the cheapest option to resolve storage costs for the vast amounts of water contaminated with tritium and other radionuclides. As Benshuo Yang and Haojun Xu from the Ocean University of China report, alternatives include underground burial, controlled vapour release, and injection into the geosphere. Japan, they add, “has chosen the most cost-efficient, but most harmful one.”

Work on the ocean dumping plan is rushing ahead, ignoring international concern. In August, TEPCO began building the infrastructure needed to release the treated radioactive water into the sea, including a kilometre-long undersea tunnel and a complex of pipes to transfer the treated water from storage tanks.

Because Japan is a major donor to Pacific Island nations, some island governments are wary of directly condemning the plan. But anti-nuclear sentiment is strong in a region that still suffers from the radioactive legacies of fifty years of cold war–era nuclear testing, and many remember previous Japanese pledges to consult about plans to dump nuclear waste.

The expert panel was appointed to help bolster the islands’ dealings with Japan. Its five members have extensive expertise in the marine environment, nuclear radiation, reactor engineering and oceanography: Ken Buesseler works at the Woods Hole Oceanographic Institution, Antony Hooker is director of the Centre for Radiation Research, Education and Innovation at the University of Adelaide, Ferenc Dalnoki-Veress is with the James Martin Center for Nonproliferation Studies at Monterey, Robert Richmond is director of the Kewalo Marine Laboratory at the University of Hawai‘i at Mānoa, and Arjun Makhijani is president of the Institute for Energy and Environmental Research, or IEER.

TEPCO’s radiological impact assessment, released in November 2021, sidestepped many of the initial concerns raised by critics of the project. Throughout 2022, the expert panel held meetings with TEPCO and Japanese officials, receiving some data on the type of radionuclides held in storage by the company. The International Atomic Energy Agency has also contributed to the debate, with director-general Rafael Grossi visiting the Fukushima Daiichi nuclear power plant in May 2022 and briefing a Forum meeting in July.

For panel member Arjun Makhijani, a former nuclear engineer and IEER expert on nuclear safety, the lack of significant data is a crucial problem.

“From a scientific point of view, we as an expert panel felt there was really insufficient information to plan this huge operation,” he tells me. “We perceived early on that because most of the storage tanks had not been sampled, most of the radionuclides are not being sampled, and so there just wasn’t enough information to proceed.”

As time went on, says Dr Makhijani, the panel’s worries about the Japanese plans became stronger. “Do they know what they are doing? Do they have enough information? Have they done the measurements properly? Do they know if the capacity of the filtration system will be enough for the volume of liquids, so the concentration of radionuclides would be low enough? How long will it take if they have to repeatedly filter the liquids? There weren’t any clear answers to these questions.”

As they met with TEPCO and Japanese authorities, the expert panel began to raise a series of concerns: the failure to accurately sample different isotopes in the storage tanks, the level of radioactive contamination in sludge at the bottom of the tanks, and the models used to determine how elements like tritium will disperse and dilute in the vast Pacific Ocean.

For Dr Makhijani, the Japanese authorities have not provided enough information to ascertain what range and amounts of radionuclides will be found in each tank. Only nine of sixty-four radionuclides have been included in the data shared with the Forum.

“The vast majority of radionuclides are not being measured, according to the Japanese authorities themselves,” Dr Makhijani says. “In summary, most of the tanks have never been sampled. The sampling they do is non-representative of the water in the tanks and when they were stored. Are the measurements of what’s in the tanks accurate? The answer to this is no.”

The bulk of the radioactivity measured in the wastewater is from two isotopes: tritium and carbon-14. But current data also show a complex mix of other highly radioactive isotopes, including strontium-90, caesium-134, caesium-137, cobalt-60 and even tellurium-127, a fission product with a short half-life of nine hours that shouldn’t be present after years of storage.

The expert panel has noted that some tanks low in tritium are high in strontium-90, and vice versa, concluding that “the assumption that concentrations of the other radionuclides are constant is not correct and a full assessment of all radioisotopes is needed to evaluate the true risk factors.”

Also of concern is the fact that particles in the water may settle to the bottom of the storage tanks over time, creating contaminated sludge. Japanese authorities have confirmed that tanks filled with cooling water in the years immediately after the 2011 accident contain contaminated sediment of this kind.

“The sludges were not sampled then and have not been sampled since that time,” says Dr Makhijani. “How much of these sludges will be stirred up and complicate the filtration system as you pump out the water from the tanks? This issue has not been addressed.”

TEPCO plans to filter out most isotopes but dump vast amounts of tritium into the Pacific, relying on rapid dispersion and dilution. But many scientists are critical of the model used to measure the dilution of tritium in seawater, which is based on models using international standards for how much naturally occurring tritium can be safely ingested in drinking water. Environmental critics of the dumping plan are concerned tritium and other radioactive isotopes will accumulate in ocean sediments, fish and other marine biota.

According to Dr Makhijani, the expert panel was concerned that the proposed drinking water standard for tritium does not apply to ocean ecosystems. “The discharged concentration of tritium will be thousands of times the background level you find naturally or through historical nuclear testing,” he explains, “and then you’re going to discharge it for many decades.”

He believes a full modelling of the impact would include “an ecosystem assessment, both for sediments and for vegetal and animal biota that travel,” which hasn’t been done. “In TEPCO’s environmental impact assessment, they didn’t take account of any bioaccumulation of tritium, which does occur in all organisms. The question of bioconcentration in an ocean environment was totally ignored in the statement.”

In its report to Forum member governments in August, the expert panel concluded that Japan’s assessments of ecological effects and bioconcentration are seriously deficient and don’t provide a sound basis for estimating impact. Writing in the Japan Times, the five scientists noted:

The release of contaminated material from the Fukushima No. 1 nuclear power plant would take at least forty years, and decades longer if you include the anticipated accumulation of new water during the process. This would impact not only the interests and reputation of the Japanese fishing community, among others, but also the people and countries of the entire Pacific region. This needs to be considered as a transboundary and transgenerational issue.

Insufficient information is available to assess how environmental and human health would be affected, they argued, and issuing a permit at this time would be premature at best: “Having studied the scientific and ecological aspects of the matter, we have concluded that the decision to release the contaminated water should be indefinitely postponed and other options for the tank water revisited until we have more complete data to evaluate the economic, environmental and human health costs of ocean release.”

The potential for long-term damage to the ocean environment is echoed by expert panel member Robert Richmond from the University of Hawai‘i at Mānoa.

“This is truly a trans-boundary issue,” he says. “Fish don’t respect political lines, and neither do radionuclides or pollutants in the ocean. I really commend the members of the Pacific Islands Forum for recognising this is an issue they need additional information on.”

Soon after the 2011 Fukushima accident, scientists confirmed that Pacific bluefin tuna can transport radionuclides across the northern Pacific Ocean. A 2012 study from Stanford University reported tuna with traces of Fukushima-related contamination had been found on the shores of the United States.

“Pacific bluefin tuna can rapidly transport radionuclides from a point source in Japan to distant ecoregions and demonstrate the importance of migratory animals as transport vectors of radionuclides,” the study reported. “Other large, highly migratory marine animals make extensive use of waters around Japan, and these animals may also be transport vectors of Fukushima-derived radionuclides to distant regions of the North and South Pacific Oceans.”

Will perceptions of radioactive hazards from Japan’s ocean dumping damage the global market for tuna? Many island nations derive vital revenue from the deepwater fishing nations that pay to operate in Pacific Island exclusive economic zones, or EEZs.

Regional organisations have also sought to process and market tuna from the Pacific as another key source of revenue. For nearly a decade, island states have supported Pacifical, a brand that promotes sustainable distribution and marketing of skipjack and yellowfin tuna caught in their EEZs.

Speaking after her recent appointment as executive director of the Western and Central Pacific Fisheries Commission, Rhea Moss-Christian highlighted the potential damage of Japan’s decades-long project: “This is a massive release and a big, big potential disaster if it’s not handled properly.”

Moss-Christian is the first Pacific woman to head the commission, which manages the largest tuna fishery in the world, representing nearly 60 per cent of global production.

“I wish that the Japanese government would take some more time before its release,” she told journalists at December’s commission meeting. “There are a number of outstanding questions that have yet to be fully answered. They have focused a lot on one particular radionuclide, and not very much on others that are also present in the wastewater.”

Moss-Christian is a citizen of the Republic of the Marshall Islands, an island nation living with the consequences of radioactive fallout from sixty-seven US atmospheric nuclear tests on Bikini and Enewetak Atolls. A former chair of the Marshall Islands National Nuclear Commission, she is deeply aware of this radioactive legacy. Her nation struggles to control radionuclides leaching into the marine environment from the Runit Dome, a nuclear waste site on Enewetak Atoll created by the United States in the 1970s.

“We have a lot of experience in the Marshall Islands with lingering radioactive waste,” Moss-Christian said. “We don’t want to find ourselves in another situation, not just in the Marshall Islands, but in general in the region, where we agree to something without knowing what could potentially happen in the future. What are the contingency plans? What are the compensation mechanisms?”

At a time of growing US–China tension, the Japanese government is seeking to boost its role in the islands region. Tokyo is building closer ties with Australia and the United States through increased military operations and joint investments in the islands. In November, for example, Tokyo and Washington agreed to contribute US$100 million to support Australian underwriting of Telstra’s purchase of Digicel, blocking Chinese investment in the Pacific’s key mobile phone network.

Even as the Japanese government seeks to win hearts and minds in the region, community anger about the nuclear threat is growing. Church and civil society groups, including the Pacific Conference of Churches, Pacific Islands Association of Non-Governmental Organisations and Pacific Network on Globalisation, have criticised the proposed wastewater dumping plan.

When Japanese foreign minister Yoshimasa Hayashi visited Fiji last May, these community groups argued the proposed ocean dumping breached international agreements like the London Convention on the Prevention of Marine Pollution. A joint civil society statement concluded, “We believe there is no scenario in which discharging nuclear waste into the Pacific Ocean is justified for the health, wellbeing, and future safety of Pacific peoples and the environment.”

As Japan forges ahead with its plan and Australia works towards acquiring nuclear submarines under the AUKUS agreement, the gulf is growing between the two countries’ geopolitical agenda and the growing antinuclear sentiment across the Blue Pacific. •