Is Fukushima doomed to become a dumping ground for toxic waste? — The Guardian

” This month, seven years after the 2011 Fukushima Daiichi reactor meltdowns and explosions that blanketed hundreds of square kilometres of northeastern Japan with radioactive debris, government officials and politicians spoke in hopeful terms about Fukushima’s prosperous future. Nevertheless, perhaps the single most important element of Fukushima’s future remains unspoken: the exclusion zone seems destined to host a repository for Japan’s most hazardous nuclear waste.

No Japanese government official will admit this, at least not publicly. A secure repository for nuclear waste has remained a long-elusive goal on the archipelago. But, given that Japan possesses approximately 17,000 tonnes of spent fuel from nuclear power operations, such a development is vital. Most spent fuel rods are still stored precariously above ground, in pools, in a highly earthquake-prone nation.

Japanese officialdom relentlessly emphasises positive messages regarding Fukushima’s short- and medium-term future, prioritizing economic development and the gradual return of skeptical evacuees to their newly “remediated” communities. Yet the return rate for the least hard-hit communities is only about 15%. Government proclamations regarding revitalisation of the area in and around the exclusion zone intone about jobs but seem geared ominously toward a future with relatively few humans.

The Fukushima prefecture government is currently promoting a plan, dubbed The Innovation Coast, that would transform the unwelcoming region into a thriving sweep of high-tech innovation. Much of the development would be directed towards a “robot-related industrial cluster” and experimental zones like a robot test field.

The test field would develop robots tailored for disaster response and for other purposes on a course simulating a wide range of hurdles and challenges already well represented in Fukushima itself. Large water tanks would contain an array of underwater hazards to navigate, mirroring the wreckage-strewn waters beneath the Fukushima Daiichi plant, where a number of meltdown-remediating underwater robots have met a premature demise in recent years.

Elsewhere on the robot test field, dilapidated buildings and other ruins would serve as a proving ground for land-based disaster-response robots, which must navigate twisted steel rods, broken concrete and other rubble. Engineered runways and surrounding radiation-hit areas would serve as prime territory for testing parlous aerial drones for a range of purposes in various weather conditions – which would be difficult or impossible to achieve elsewhere in relatively densely populated Japan.

The planned site for the test field would link with a secluded test area about 13km south along the coast to coordinate test flights over the exclusion zone’s more or less posthuman terrain.

Naturally, unlike Fukushima’s human residents, robots would be oblivious to the elevated radiation levels found outside the Fukushima Daiichi facility. In addition, prefectural officials have suggested that the exclusion zone environs could play host to a range of other services that don’t require much human intervention, such as long-term archive facilities.

Proud long-time residents of Fukushima, for their part, see all this development as a continued “colonisation” of the home prefecture by Tokyo – a well-worn pattern of outsiders using the zone for their own purposes, as were the utility representatives and officials who built the ill-fated plant in the first place.

Years of colossal decontamination measures have scraped irradiated material from seemingly every forest, park, farm, roadside, and school ground. This 16 million cubic metres of radioactive soil is now stored in provisional sites in and around the exclusion zone, waiting to be moved to an interim storage facility that has hardly been started and for which nearly half of the land has not yet even been leased.

The state has promised to remove all the contaminated soil from Fukushima after 30 years, and government officials have been scrupulous in insisting that this will be the case – for soil. Yet in a nation with about 17,000 tonnes of highly radioactive spent fuel rods and no willing candidates for secure repositories, it is only a matter of time before it becomes possible for politicians to publicly back the idea of transforming the area around Fukushima Daiichi into a secure repository.

Government officials, including those tasked with nuclear waste storage, describe the quintessentially Japanese strategy of saki-okuri, or calculated postponement, in the context of nuclear waste storage. Such perception management is a subtle business, but by quietly and unrelentingly pushing back the day of reckoning – slowly changing the terms of debate – the broadly distasteful prospect of storing Japan’s most dangerous material in its most tragically maltreated region would become gradually less intolerable to Japanese sensibilities.

The expanse of Fukushima in and around the exclusion zone represents an already contaminated area with, since 2011, far fewer residents to protest against such plans. Such a rare opportunity for relatively unopposed intervention in a struggling area will surely prove irresistible to the nuclear lobby.

Fukushima has been marginalised, disenfranchised, and outmanoeuvred for decades. After all, the electricity from Fukushima Daiichi went straight to the capital, not to Fukushima itself, which bore the risks. Since 2011, Fukushima has been saddled with the staggering burden of the meltdown’s aftermath that, despite government PR, will encumber and stigmatise its citizens for at least several decades. ”

by Peter Wynn Kirby, The Guardian

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Clearing the radioactive rubble heap that was Fukushima Daiichi, 7 years on — Scientific American

” Seven years after one of the largest earthquakes on record unleashed a massive tsunami and triggered a meltdown at Japan’s Fukushima Daiichi nuclear power plant, officials say they are at last getting a handle on the mammoth task of cleaning the site before it is ultimately dismantled. But the process is still expected to be a long, expensive slog, requiring as-yet untried feats of engineering—and not all the details have yet been worked out.

When the disaster knocked out off- and on-site power supplies on March 11, 2011, three of the cooling systems for the plant’s four reactor units were disabled. This caused the nuclear fuel inside to overheat, leading to a meltdown and hydrogen explosions that spewed out radiation. The plant’s operator, Tokyo Electric Power Co. (TEPCO), responded by cooling the reactors with water, which continues today. Meanwhile thousands of people living in the surrounding area were evacuated and Japan’s other nuclear plants were temporarily shut down.

In the years since the disaster and the immediate effort to stanch the release of radioactive material, officials have been working out how to decontaminate the site without unleashing more radiation into the environment. It will take a complex engineering effort to deal with thousands of fuel rods, along with the mangled debris of the reactors and the water used to cool them. Despite setbacks, that effort is now moving forward in earnest, officials say. “We are still conducting studies on the location of the molten fuel, but despite this we have made the judgment that the units are stable,” says Naohiro Masuda, TEPCO’s chief decommissioning officer for Daiichi.

Completely cleaning up and taking apart the plant could take a generation or more, and comes with a hefty price tag. In 2016 the government increased its cost estimate to about $75.7 billion, part of the overall Fukushima disaster price tag of $202.5 billion. The Japan Center for Economic Research, a private think tank, said the cleanup costs could mount to some $470 billion to $660 billion, however.

Under a government roadmap, TEPCO hopes to finish the job in 30 to 40 years. But some experts say even that could be an underestimate. “In general, estimates of work involving decontamination and disposal of nuclear materials are underestimated by decades,” says Rod Ewing, a professor of nuclear security and geological sciences at Stanford University. “I think that we have to expect that the job will extend beyond the estimated time.”

The considerable time and expense are due to the cleanup being a veritable hydra that involves unprecedented engineering. TEPCO and its many contractors will be focusing on several battlefronts.

Water is being deliberately circulated through each reactor every day to cool the fuel within—but the plant lies on a slope, and water from precipitation keeps flowing into the buildings as well. Workers built an elaborate scrubbing system that removes cesium, strontium and dozens of other radioactive particles from the water; some of it is recirculated into the reactors, and some goes into row upon row of giant tanks at the site. There’s about one million tons of water kept in 1,000 tanks and the volume grows by 100 tons a day, down from 400 tons four years ago.

To keep more water from seeping into the ground and being tainted, more than 90 percent of the site has been paved. A series of drains and underground barriers—including a $325-million* supposedly impermeable “wall” of frozen soil—was also constructed to keep water from flowing into the reactors and the ocean. These have not worked as well as expected, though, especially during typhoons when precipitation spikes, so groundwater continues to be contaminated.

Despite the fact contaminated water was dumped into the sea after the disaster, studies by Japanese and foreign labs have shown radioactive cesium in fish caught in the region has fallen and is now within Japan’s food safety limits. TEPCO will not say when it will decide what to do with all the stored water, because dumping it in the ocean again would invite censure at home and abroad—but there are worries that another powerful quake could cause it to slosh out of the tanks.

Fuel Mop-up

A second major issue at Fukushima is how to handle the fuel¾the melted uranium cores as well as spent and unused fuel rods stored at the reactors. Using robotic probes and 3-D imaging with muons (a type of subatomic particle), workers have found pebbly deposits and debris at various areas inside the primary containment vessels in the three of the plant’s reactor units. These highly radioactive remains are thought to be melted fuel as well as supporting structures. TEPCO has not yet worked out how it can remove the remains, but it wants to start the job in 2021. There are few precedents for the task. Lake Barrett—director of the Three Mile Island nuclear plant during its decommissioning after a partial meltdown at the Middletown, Pa., facility in 1979—says TEPCO will use robots to remotely dig out the melted fuel and store it in canisters on-site before shipping to its final disposal spot. “This is similar to what we did at Three Mile Island, just much larger and with much more sophisticated engineering because their damage is greater than ours was,” Barrett says. “So although the work is technically much more challenging than ours was, Japan has excellent technological capabilities, and worldwide robotic technology has advanced tremendously in the last 30-plus years.”

Shaun Burnie, senior nuclear specialist with Greenpeace Germany, doubts the ambitious cleanup effort can be completed in the time cited, and questions whether the radioactivity can be completely contained. Until TEPCO can verify the conditions of the molten fuel, he says, “there can be no confirmation of what impact and damage the material has had” on the various components of the reactors—and therefore how radiation might leak into the environment in the future.

Although the utility managed to safely remove all 1,533 fuel bundles from the plant’s unit No. 4 reactor by December 2014, it still has to do the same for the hundreds of rods stored at the other three units. This involves clearing rubble, installing shields, dismantling the building roofs, and setting up platforms and special rooftop equipment to remove the rods. Last month a 55-ton dome roof was installed on unit No. 3 to facilitate the safe removal of the 533 fuel bundles that remain in a storage pool there. Whereas removal should begin at No. 3 sometime before April 2019, the fuel at units No. 1 and 2 will not be ready for transfer before 2023, according to TEPCO. And just where all the fuel and other radioactive solid debris on the site will be stored or disposed of long-term has yet to be decided; last month the site’s ninth solid waste storage building, with a capacity of about 61,000 cubic meters, went into operation.

As for what the site itself might look like decades from now, cleanup officials refuse to say. But they are quick to differentiate it from the sarcophagus-style containment of the 1986 Chernobyl catastrophe in the Soviet Union, in what is now Ukraine. Whereas the Chernobyl plant is sealed off and the surrounding area remains off-limits except for brief visits—leaving behind several ghost towns—Japanese officials want as many areas as possible around the Daiichi site to eventually be habitable again.

“To accelerate reconstruction and rebuilding of Fukushima as a region, and the lives of locals, the key is to reduce the mid- and long-term risk,” says Satoru Toyomoto, director for international issues at the Ministry of Economy, Trade and Industry’s Nuclear Accident Response Office. “In that regard, keeping debris on the premises without approval is not an option.” ”

by Tim Hornyak, Scientific American

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