Almost 12 years have passed since the strongest earthquake in Japan’s recorded history resulted in a tsunami that killed more than 18,000 people along its north-east coast.
As the country prepares to mark the March 11 anniversary, one of the disaster’s most troubling legacies is about to come into full view with the release of more than 1m tonnes of “treated” water from the destroyed Fukushima Daiichi nuclear power plant.
The tsunami knocked out the plant’s backup electricity supply, leading to meltdowns in three of its reactors, in the world’s worst nuclear accident since Chornobyl 25 years earlier.
Much has changed since the Guardian’s first visit to the plant in 2012, when the cleanup had barely begun and visitors were required to wear protective clothing and full-face masks. Atmospheric radiation levels have dropped, damaged reactor buildings have been reinforced and robots have identified melted fuel in the basements.
But as the Guardian learned on a recent visit, progress on decommissioning – a process that could take four decades – is being held up by the accumulation of huge quantities of water that is used to cool the damaged reactor cores.
Now, 1.3m tonnes of water – enough to fill about 500 Olympic-sized swimming pools – is being stored in 1,000 tanks that cover huge swathes of the complex. And space is running out.
Two steel pillars protruding from the sea a kilometre from the shore mark the spot where, later this year, the plant’s operator, Tokyo Electric Power [Tepco], plans to begin releasing the water into the Pacific Ocean, in the most controversial step in the Fukushima Daiichi cleanup to date.
The decision comes more than two years after Japan’s government approved the release of the water, which is treated using on-site technology to remove most radioactive materials. But the water still contains tritium, a naturally occurring radioactive form of hydrogen that is technically difficult to separate from water.
The discharge, which is due to begin in the spring or summer, will take place in defiance of local fishing communities, who say it will destroy more than a decade of work to rebuild their industry. Neighbouring countries have also voiced opposition.
The government and Tepco claim the environmental and health impacts will be negligible because the treated water will be released gradually after it has been diluted by large amounts of seawater. The International Atomic Energy Agency says nuclear plants around the world use a similar process to dispose of wastewater containing low-level concentrations of tritium and other radionuclides.
Tepco and government officials who guided a small group of journalists around Fukushima Daiichi this month insisted the science supports their plans to pump the “treated” water – they object to media reports describing it as contaminated – into the ocean.
The water will be treated and, if necessary, treated again until the concentration of radionuclides other than tritium have fallen below government limits, said Hikaru Kuroda, a Tepco official overseeing the decontamination and decommissioning of Fukushima Daiichi. “By the time the liquid is diluted with seawater, tritium levels will be at less than 1,500 becquerels per litre, or 1/40th of the government standard for discharging water into the environment,” he said.
“We will have contaminated water on the site for as long as we have to cool the reactor basements. And we will release the water very slowly to begin with, so we could be looking at something like 20 to 30 years to complete the process.”
The fiercest opposition has come from Fukushima’s fishers, who say releasing the water risks destroying their livelihoods because consumers will shun their catch and send prices plummeting.
“Even though it is safe, it could still harm sales of Fukushima seafood and lower prices, which is what happened 12 years ago,” conceded Junichi Matsumoto, Tepco’s chief officer for the management of treated water. “We know fishing communities are worried … that’s why we and the government are working on addressing the potential reputational damage.”
The Fukushima prefectural government says that, post-disaster, its food safety standards are among the strictest in the world. The government-set upper limit for radioactive caesium in ordinary foodstuffs such as meat and vegetables is 100 becquerels a kilogram, compared with 1,250Bq/kg in the EU and 1,200Bq/kg in the U.S.
While officials attempt to reassure the public and other countries that Fukushima produce is safe for consumers, Tepco and the government have embarked on a PR offensive, holding regular briefings on the water discharge for Tokyo-based diplomats and journalists, and running ads on TV, in newspapers and online.
“We take other countries’ concerns seriously, which is why we are using every possible opportunity to explain the discharge plan to them,” said Ayako Ogino, a foreign ministry official. “We have made a commitment to discharge the water without harming the environment or human health. To describe the water as contaminated is erroneous, as it implies that it will harm the environment.”
The campaign has had mixed results. South Korea and China have voiced opposition to the discharge, while the Pacific Islands Forum (PIF) said recently it had “grave concerns”.
Environmental groups have challenged the Japanese government’s claims that the water will not affect marine life or human health, while the US National Association of Marine Laboratories has pointed to a lack of adequate and accurate scientific data to support its reassurances on safety.
The water release plan received a boost this month, however, when Micronesia, a member of the PIF, dropped its opposition to the water discharge. Its president, David Panuelo, said in Tokyo that his country was “no longer fearful or concerned about this issue now as we trust in Japan’s intention and technological capabilities in not harming our shared oceanic interests”.
Japanese officials have ruled out other options, including long-term storage underground or evaporation, and insist nothing will stand in the way of the discharge plans. “The biggest obstacle to decommissioning Fukushima Daiichi is the debris [inside the reactors],” said Atsushi Wakui, a nuclear accident official at the economy, trade and industry ministry. “Securing the site so we can begin removing the melted fuel is absolutely essential, and that means urgently addressing the water problem. There are more than 1,000 tanks of water here, and they need to go,” said Wakui.