nuclear-news

Not even the icy wind blowing in from the coast seems to bother the men in protective masks, helmets and gloves, playing their part in the world’s biggest nuclear cleanup.

Away from the public gaze, they remove the latest of the more than 1,000 black sacks filled with radioactive soil and unload their contents into giant sieves. A covered conveyor belt carries the soil to the lip of a huge pit where it is flattened in preparation for the next load. And there it will remain, untouched, for almost three decades.

It is repetitive, painstaking work but there is no quick way of addressing arguably the most controversial physical legacy of the triple meltdown that occurred eight years ago at the nearby Fukushima Daiichi nuclear power plant.

In the years after the disaster, about 70,000 workers removed topsoil, tree branches, grass and other contaminated material from areas near homes, schools and public buildings in a unprecedented ¥2.9tn (£21bn) drive to reduce radiation to levels that would enable tens of thousands of evacuees to return home.

The decontamination operation cleaned generated millions of cubic metres of radioactive soil, packed into bags that carpet large swaths of Fukushima prefecture.

Japan’s government has pledged that the soil will moved to the interim storage facility and then, by 2045, to a permanent site outside of Fukushima prefecture as part of a deal with local residents who do not want their communities turned into a nuclear dumping ground.

But the government’s blueprint for the soil is unravelling: so far, not a single location has agreed to accommodate the toxic waste.

While workers inside the ruined nuclear plant struggle to contain the build-up of more than 1m tonnes of radioactive water, outside, work continues to remove, process and store soil that will amount to 14m cubic metres by 2021.

The task is expected to take another two years, according to Jiro Hiratsuka, an environment ministry official who is guiding a small group of foreign journalists, including the Guardian, around the interim storage facility.

“We are required by law to find a final storage place outside Fukushima, so it can’t be kept here indefinitely,” Hiratsuka said. “It’s true that we have yet to find an appropriate location, but a lot will depend on how much space we need and the level of radioactivity in the soil.”

There is opposition, too, to the idea of using soil with lower radiation levels – or less 8,000 becquerels per kilogram – as the foundation for roads, embankments and other infrastructure in Fukushima.

The storage facility straddles the towns of Okuma and Futaba, located west of the power plant, where radiation levels are still too high for residents to return. So far, 2.3m cubic metres of soil – about 15% of the total – have been brought to the site.

The operation involves thousands of workers, including drivers who make 1,600 return trips every day. So far, 355,000 trucks have been used – and officials say they need more.

“I am aware that some people are saying it would be better to keep it here, but the people of Okuma and Futaba have had a really tough time, and they agreed the soil could be kept here on the condition that it would eventually be moved out of Fukushima,” Hiratsuka said.

Despite the decontamination efforts, only a small number of residents who were ordered to leave after the triple meltdown have returned to neighbourhoods where evacuation orders have been lifted, according to local government data.

A poll by the Asahi newspaper and a local broadcaster found that almost two-thirds of evacuated residents felt anxious about radiation despite official claims that decontamination work had been a success.

As Japan marked the eighth anniversary on Monday of the magnitude-9 earthquake and deadly tsunami that triggered the Fukushima meltdown, environmental groups warned that some “safe” neighbourhoods still contained radiation hotspots.

A Greenpeace investigation revealed high levels of radiation in areas that had been declared safe, and accused the government of misleading the international community about the risks faced by returning evacuees and decontamination workers.

“Some areas still have significantly high levels of radiation,” said Shaun Burnie, a senior nuclear specialist at Greenpeace Germany who is based in Japan. “They are much higher than background radiation before the accident.”

Minoru Ikeda, who took part in the decontamination effort, said workers cut corners to meet strict deadlines. “There were times when we were told to leave the contaminated topsoil and just remove the leaves so we could get everything done on schedule,” he said. “Sometimes we would look at each other as if to say: ‘What on earth are we doing here?’”

He was sceptical of official claims that a permanent home would be found the for soil. “I don’t believe for a minute that they will be able to move all that soil out of Fukushima,” he said. “The government has to come up with a plan B.”