Video: Robots approach reactors to map radiation

IN THE dark abandoned shell of Fukushima Daiichi nuclear power plant, Rosemary and Sakura shoot what looks like a dystopian first-person shooter game. Rosemary scans her environment, while Sakura records every move.

But this is no traditional film crew. Rosemary and Sakura are robots operated by Tepco, the firm running the plant that went into meltdown following the March 2011 earthquake and tsunami. Using radiation-sensing cameras they perform surveys in areas where radiation levels are still too high for humans to safely enter. The data the robots collect will help plan how to decommission the plant.

“Rosemary and Sakura can perform surveys in areas where radiation levels are too high for humans”

Tepco has recently had problems with robots. On 10 April, it sent a robot inside the primary containment vessel of reactor 1 to measure radiation levels and investigate the condition of the melted fuel. But the robot stopped working on its first inspection and had to be abandoned. Radiation levels as high as 5150 millisieverts per hour have been detected in the basement of reactor 1.

Developed at the Chiba Institute of Technology, Rosemary and Sakura can climb 45 degree slopes and use gyroscopes and other sensors to navigate inside buildings without the need for GPS. But the standard radiation detector, gamma cameras weighing 150 kilograms, proved too cumbersome for them to use.

So the team has turned to a gamma camera that weighs just 17 kilograms and can rotate 360 degrees. This has been added to the robots as part of a system called N-Visage, which also includes a laser scanner that draws a 3D image of its environment.

The radiation measurements can be combined with a laser scan of the plant’s exact layout, says Trevor Craig of UK start-up Createc, which developed N-Visage for Japan’s International Research Institute for Nuclear Decommissioning, and reactor maker Hitachi. An earlier version was used in Sellafield in Cumbria.

Rosemary operates N-Visage, while Sakura acts as a wireless transmission station, feeding the data to human operators located in the plant’s seismic-proof centre 200 metres away. They also get a fisheye view via cameras attached to the two robots.

In addition to creating real-time maps of radiation levels, the associated software can also predict how they will evolve as the facility is modified or taken apart. “Once we have a model like this we can play scenarios to find out what happens to dose rates if we decontaminate this wall, or put shielding next to highly contaminated fuel handling machinery,” says Craig. “It helps work out what the decommissioning plan should be.”

To date the N-Visage system has been used in the first three reactors at Fukushima. Createc is adapting the technology for use inside a snake-arm robot to delve even deeper into the reactors in an attempt to discover exactly where the fuel ended up.

This article appeared in print under the headline “Deep inside Fukushima”

It seems the most unlikely place to try to put a utopian blueprint into practice. Yet a patch of land in Fukushima, the Japanese prefecture contaminated by nuclear fallout in 2011, holds the foundations of a model village of the future.

The prefecture was affected by the meltdowns at the Fukushima Daiichi nuclear plant, following the earthquake and subsequent tsunami in March 2011. Now construction has started on a community-run project in the coastal city of Minamisoma to reuse farmland contaminated by fallout. About two-thirds of the city’s farmland lies within the nuclear evacuation zone.

So far the Renewable Energy Village (REV) boasts 120 photovoltaic panels, generating 30 kilowatts of power which is sold to a local utility. Plans are afoot to put wind turbines on some of the land. Recreational and educational facilities as well as an astronomical observatory will also be built if further funding can be secured.

Solar sharing

Central to the project is what the Japanese call “solar sharing” – growing crops beneath raised solar panels. One crop that has already been planted, namely rapeseed, was chosen, say project organisers, because its oil is free of contaminants even though the plants themselves take in some radioisotopes such as those of caesium. Generous set by the government support the project.

While the proceeds from the crops and energy will be ploughed back into the project, the REV’s creators hope the model will be mimicked by farmers whose livelihoods were decimated by the nuclear disaster. “People evacuated from areas closer to the plant have given up ever farming their fields again,” says project leader Ryozo Hakozaki. “There might be an amusement park feel to the project, but we’re trying to show them what the future could hold.”

Since the feed-in tariff was introduced in mid-2012, several other large-scale solar parks around Japan have been announced or are already in operation – but none uses solar sharing. Most have solar panels resting on the ground itself, which makes growing crops impossible. One will be the country’s largest solar park, also in Minamisoma.

Hakozaki says such large-scale ventures could threaten Minamisoma’s farming traditions. “If farmers decide to sell up their land, entire communities will be wiped off the map.”

The Renewable Energy Village model offers a way around this issue, says project chairman Sohei Takahashi, who plans to conduct research into crops that can tolerate radioactive contamination. “Through the project we can protect farmland and communities, and with two parallel revenues create increased prosperity compared with before the disasters,” he says.

This article appeared in print under the headline “Fukushima renews”

An ultra-thin fault zone packed with slippery clay was behind the massive seismic slip during Japan’s devastating Tohoku earthquake of 2011. The quake was so great that it permanently changed the region’s gravitational field, and was “heard” from space.

To find out how such a large slip – in excess of 50 metres in places – happened, teams of seismologists on board Japan’s deep-sea research vessel Chikyu drilled into the seabed around the plate boundary that ruptured during the Tohoku earthquake. They took measurements in boreholes reaching 844 metres beneath the seabed.

The results, published in a collection of studies this week, revealed a significant presence of smectite, a slippery clay largely responsible for many major landslides in Europe (). Temperature measurements confirmed the fault had a coefficient of friction of only 0.1, making it very likely to shift. Most rocks slip at about 0.5 or 0.6, says James Mori of the Disaster Prevention Research Institute at Kyoto University ().

What’s more, the fault zone was found to be less than 5 metres thick, tens of times thinner than at other subduction zones.

“One of the main goals was to try and explain the massive slip, which we had never seen before in an earthquake,” says Mori. It seems that subduction zones with particularly thin fault zones and a lot of smectite can produce slips of more than 50 metres, he adds, and potentially give rise to large tsunamis.

Infrasound

The Tohoku slip was so big that the infrasound waves generated by the quake propagated more than 200 kilometres through the atmosphere. That disturbed the orbit of the European Space Agency’s GOCE satellite ().

GOCE measures small variations in Earth’s gravity field, which changes with the shape of the landscape and density of the crust. Yesterday, researchers at the German Geodetic Research Institute in Munich and Delft University of Technology in the Netherlands released more GOCE data showing that the quake has caused subtle changes in the local gravity field.

“This will continue to help us explain the mechanism of future earthquakes,” says Robert Geller, a seismologist at the University of Tokyo, “but I don’t think it is going to help us to say when or where the next one will occur.”

IT’S A creepy sensation, having a little keyboard permanently emblazoned on the back of my hand. No matter what I do – shake my hand or wave it – I can’t make it go away. Creepier still are the soft tingles on my skin as each “key” is pressed, like a low-frequency electronic buzz.

I am in at the University of Tokyo, Japan, where the latest in interactive projections is being demonstrated for the first time. The set-up is in two parts: one is a projection that beams the outline of computer keyboards or cellphone keys onto any object, such as your hand.

Projecting interactive outlines of devices has been done before, but it is a lot trickier doing it on a moving object. Ishikawa’s system detects and maps the position of an object 500 times per second and projects an image onto it. It automatically controls a camera’s pan and tilt angles to ensure it is locked onto an object no matter how fast it moves. Ishikawa once demonstrated this technology by tracking a table-tennis ball in play.

The set-up also has a tactile angle. The information about the exact location of your hand and the orientation of the projected keypad is fed to a second system, called the Airborne Ultrasound Tactile Display. This makes the illuminated points on your hand or body slightly tingle with what feels like a jet of air. It’s an odd feeling, but I find it makes the projected image seem more real.

The sensation on the hand is generated by sound beamed by 2000 or so ultrasonic wave emitters, says its developer Hiroyuki Shinoda, also at the University of Tokyo. The carefully timed and directed sound beams can make any spot vibrate within a given cubic metre.

The combined system has already attracted interest from the auto, medical and gaming industries, says Ishikawa.

Fishermen in Japan have adopted a new way of killing dolphins in drive hunts – but the method is no more humane than the previous techniques, say vets and dolphin behaviour experts.

Japanese dolphin culls received global attention in 2009, after the release of the Oscar-winning documentary The Cove. It showed in graphic detail how each year, hundreds of dolphins were herded into a cove near the fishing village of Taiji, and killed with knives and spears. In the film the cove waters turned crimson with blood.

In 2010, Toshihide Iwasaki of Far Seas Fisheries and Yoshifumi Kai of the Taiji Fisheries Cooperative another supposedly more humane method to cull dolphins. This involves using a thin rod to impale dolphins behind their blowhole and sever the spinal cord.

They said tests had shown that the animals died faster and as a consequence the method was adopted officially. In the case of four striped dolphins (Stenella coeruleoalba), the shortest time to death was said to be 5 seconds, considerably less than the 300 seconds using conventional practices.

Covert footage

A new study refutes these claims. “Our analysis shows that this method does not fulfil the internationally recognised requirement for immediacy,” says of the University of Bristol Veterinary School, UK. “It would not be tolerated or permitted in any regulated slaughterhouse process in the developed world.”

Butterworth and his colleagues assessed video footage of the Taiji cull, filmed covertly in 2011 for . They say dolphins took longer to die than the Japanese team claim. One striped dolphin, say Butterworth and colleagues, was still moving 254 seconds after being impaled.

They add that the criteria used in the Japanese report to determine time of death – termination of breathing and movement – is flawed. Any animal that has just had its spinal cord severed is likely to stop moving, they say. And dolphins are known for their ability to hold their breath for extended periods of time.

In drive hunts the animals are tethered to boats by their tail flukes to herd them into the culling cove. “From a scientific, humane, and ethical perspective, [this] sharply contradicts animal welfare standards employed in most modern and technologically advanced societies,” says team member of City University in New York.

“In the US and UK, regulations and guidelines governing the humane treatment and slaughter of animals prohibit the killing of an animal in the presence of other animals.”

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A Taiji fisheries official told me in 2009 that such reactions were “hypocritical” and “racially motivated”, saying that spinal cord transection was also practised on chickens and other animals in the West. The new study argues that accuracy is a problem when severing the spinal cord in large animals like dolphins.

Ultimately, blood loss induces first paraplegia and later death, says the report. The process is prolonged by inserting a wooden peg into the wound, which Iwasaki and Kai said was done to prevent water contamination and to conserve the blood for commercial use.

of Emory University in Atlanta, Georgia says the decision to focus on the culling method is unfortunate as it implies there is a humane way to kill a dolphin.

Asked if there are other killing methods that would be considered more humane, Reiss said: “The killing of dolphins is indefensible given our scientific knowledge of dolphins, which has demonstrated their sophisticated cognitive abilities including self and social awareness.”

“We should ensure that dolphins receive the highest standards of treatment in any hunt, equal to that granted to domestic animals,” says Kris Simpson of International Dolphin Watch. “This is clearly not being achieved, nor, under conditions in the wild, is it ever likely to be. Our position is therefore unequivocal; the dolphins must not be hunted.”

Journal reference: , DOI: 10.1080/10888705.2013.768925

From a distance they look like two giant blancmanges or Jell-Os quivering in the biting midwinter wind. On closer inspection they are in fact white nylon domes, erected alongside thousands of photovoltaic panels on the very fields in Fukushima that were ravaged by tsunami waves and nuclear fallout in 2011.

The domes and panels are part of a self-sustaining solar-powered agriculture project that opened today just 25 km from the Fukushima No.1 nuclear power plant, which went into meltdown following the biggest quake and tsunami in Japan’s recorded history exactly two years ago.

What’s more, at the helm of the Fukushima Recovery Solar-Agri Park in Minamisoma City is a former executive of the stricken nuclear plant’s operator, the Tokyo Electric Power Company (Tepco).

“I can’t help feeling a responsibility for the nuclear disaster,” said Eiju Hangai, 59, who quit Tepco just months before the disasters and who hails from Minamisoma. “It destroyed entire communities. After the disasters I vowed to find a way to help a recovery process that could take 20 or 30 years.”

More than 2000 solar panels installed by Hangai’s newly established company will supply energy to the two “vegetable factory” domes, inside which farmers affected by the disasters will be able to grow produce. Around 64 tons of its lettuce will be bought in bulk by a major supermarket chain.

Wheels with pockets

The air-inflated greenhouse domes have a unique layout like a wheel, with rotating “pockets” that accommodate the crops radiating out of the centre at regular intervals. This means that farmers do not have to traipse up and down to sow and harvest, but can work from the centre of each wheel instead. The set-up doubles the capacity and efficiency of conventional greenhouses, Hangai said.

The produce is grown hydroponically – without soil – making temperature regulation important. Accurate temperature and moisture regulation is achieved via a computer system. The optimal conditions mean produce can be grown considerably faster that usual.

Surplus energy, enough to power 170 households, says Hangai, will be sold as feed-in tariff to the Tohoku Electric Power Company, a major utility in the region. It wants to build a new nuclear power plant in Minamisoma despite objections by the city.

“This means both components of the project are economically viable,” said Hangai, who also secured government and corporate sponsorship to start the project. “It can serve as a model for industrial recovery in the disaster-stricken area.”

The 2.4-hectare site will also house an education facility to raise awareness of new energies among schoolchildren, according to Hangai. In his Tepco days, he created the J-Village sports complex that was later used as quarters for workers charged with bringing the crippled nuclear power facility under control.

The solar-agri park will join the ranks of other local projects such as the world’s largest off-shore wind farm and Japan’s biggest solar park that will facilitate Fukushima’s plan to be completely self-sufficient in renewable energy by 2040.

Hangai believes the future of nuclear in Japan must be decided by the public. “Before it was professionals who told the public what was the best energy mix for them. The professionals caused an accident. Next it’s the turn of the public to decide and for the professionals to respond to their wishes.”

It’s goodbye nuclear, hello renewables as Japan prepares to build the world’s largest offshore wind farm this July.

By 2020, the plan is to build a total of 143 wind turbines on platforms 16 kilometres off the coast of Fukushima, home to the stricken Daiichi nuclear reactor that hit the headlines in March 2011 when it was damaged by an earthquake and tsunami.

The wind farm, which will generate 1 gigawatt of power once completed, is part of a national plan to increase renewable energy resources following the post-tsunami shutdown of the nation’s 54 nuclear reactors. Only two have since come back online.

The project is part of Fukushima’s plan to become completely energy self-sufficient by 2040, using renewable sources alone. The prefecture is also set to build the country’s biggest solar park.

The wind farm will surpass the 504 megawatts generated by the 140 turbines at the Greater Gabbard farm off the coast of Suffolk, UK – currently the world’s largest farm. This accolade will soon pass to the in the Thames Estuary, where 175 turbines will produce 630 megawatts of power when it comes online later this year. The Fukushima farm will beat this, too.

Massive construction

The first stage of the Fukushima project will be the construction of a 2-megawatt turbine, a substation and undersea cable installation. The turbine will stand 200 metres high. If successful, further turbines will be built subject to the availability of funding.

To get around the cost of anchoring the turbines to the sea bed, they will be built on buoyant steel frames which will be stabilised with ballast and anchored to the 200-metre-deep continental shelf that surrounds the Japanese coast via mooring lines.

Once the farm is running at full power, the intention is that it will supply electricity to the powerful grid which Fukushima’s two nuclear power plants were connected to, reducing transmission costs.

Project manager Takeshi Ishihara of the University of Tokyo insists that the area’s seismic activity won’t be an issue for the turbines. His team have carried out computer simulations and water tank test to verify the safety of the turbines not just in the event of an earthquake or tsunami but also in other extreme conditions such as typhoons. “All extreme conditions have been taken into consideration in the design,” he says.

Another contentious issue is the facility’s impact on the fishing industry, which has already been rocked by the nuclear accident. Ishihara insists it is possible to turn the farm into a “marine pasture” that would attract fish. While there was some objections to the project by local people, Ishihara says is confident he has won them round. “This is hard work, but will be resolved this month,” he says. “This project is important – I think it is impossible to use nuclear power in Fukushima again.”

IN THE heart of Tokyo an iconic skyscraper, the Grand Prince Hotel Akasaka, is being demolished. But there are no explosives or wrecking balls in sight. Instead, all that can be seen is the roof slowly sinking as the aluminium-clad building shrinks beneath it.

The demolition is being carried out by the , which has developed what it claims is a cleaner and more environmentally friendly way to tear down high-rises. Called the Taisei Ecological Reproduction System, it works from the top down, breaking a building apart floor by floor. The once 140-metre tall hotel is now missing its top 30  metres. By May it will have vanished.

The levels being dismantled are sealed within an enclosure that wraps around the building (see time-lapse photo), while huge jacks slowly lower the original roof down as floors are removed. Fully enclosing the demolition area reduces the volume of dust particles emitted from the site by a factor of 100 compared with conventional methods, says Taisei’s Hideki Ichihara.

Before demolition begins, all non-structural elements of the building are removed by hand. Workers then take out beams and concrete flooring, which are carried to ground level by a crane system that generates electricity as the pieces are lowered. By recycling building materials and getting rid of heavy machinery that runs on fossils fuels, Ichihara says, the process reduces carbon dioxide emissions by as much as 85 per cent.

In Japan alone there are 797 skyscrapers over 100 metres tall, around 150 of which will be between 30 and 40 years old in the next decade, says Ichihara. This has historically been the age when such buildings are earmarked for demolition, but conventional methods are not suitable for such tall skyscrapers. This has prompted Taisei and its competitors Kajima and Takenaka Corporations to develop new demolition systems. Kajima’s “cut and down” method dismantles floors from the ground up, while Takenaka’s approach is almost identical to Taisei’s.

Whether the country’s current crop of high-rises should have such a short life span is a matter of debate. After Tokyo was shaken by earthquakes in March 2011, the prominent billionaire property developer Akira Mori called for the country to stop building skyscrapers over 100  metres high. Instead he suggested lower, wider-based structures should be built.

No such restrictions have yet been imposed. Takuro Yoshida, a professor at Kogakuin University in Tokyo, argues that newer engineering techniques could keep buildings safely standing for longer periods. “The idea that buildings are rebuilt on a 30- to 40-year cycle is itself about 20 years old,” he says, adding that the ecological benefits of keeping a building in service outweigh even the most efficient means of demolition.

THE green-and-white door slides shut and a man in a blue cap and beige overalls mutters into his walkie-talkie. He raises a blue-gloved hand to signal departure and we’re off. The train’s two carriages stutter into motion, trundling along the elevated rails before speeding up as they roll down the gently undulating track. The journey is short, smooth and almost silent – it’s a mere 100 metres between “stations”.

The Eco-Ride train feels like a ride on a roller coaster – and that’s pretty much what it is. In a few years’ time, this cheap and energy-efficient train could be ferrying passengers around areas of Japan devastated by last year’s tsunami.

Developed at Tokyo University’s Institute of Industrial Science (IIS), with the help of amusement ride firm Senyo Kogyo, Eco-Ride works in the exactly the same way as a theme park roller coaster. By turning potential energy into kinetic energy, it coasts along its tubular tracks without an engine. The train’s speed is controlled by aerodynamics and by “vertical curves”, sections of track that form the transition between two sloping segments. The Eco-Ride is set in motion and slowed at stations via rotating wheels between the rails that catch a fin underneath the train.

When fully installed, Eco-Ride would ply a route, ideally circular, at speeds of up to 60 kilometres per hour. The idea is that Eco-Ride will use its own inertia to get up most slopes but may on occasion need to be winched up steeper inclines. If it was first lifted to a height of 10 metres, the train could comfortably cover a distance of 400 metres, says its developer, Yoshihiro Suda, director of the IIS Advanced Mobility Research Center.

The lack of any engine makes carriages extremely light, so the energy required to propel them is small and the emissions low. Plus there is no need for the expensive, bulky infrastructure that usually accompanies the building of new train tracks.

“This is probably the ultimate energy-saving transportation system,” says Suda. A number of municipalities in Japan have shown an interest in the system, including communities hit by last year’s devastating earthquake and tsunami in the Tohoku region in the north-east, he says. Other uses could be feeder routes between other transportation networks, or communities and college campuses located beyond what might be considered a reasonable walking distance, he added. Suda expects the first Eco-Ride to be in operation sometime in 2014.

“Eco-Ride is probably the ultimate energy-saving transport system, ideal for earthquake-hit towns”

The prototypes that scuttle down the track at the leafy suburban test facility in Chiba already look good to go, and efforts have been made to create a genuine travel experience. Having climbed up the steps to the makeshift platform I hand in my Eco-Ride ticket – on it are printed the date and time of departure and a request to be ready to board 5 minutes prior to departure. A poster at the station explains various technical aspects of the system and includes a computer-generated image of an Eco-Ride winding its way among city skyscrapers and above the cars and pedestrians below (see top right).

That might seem a bit far off but Eco-Ride would be perfect for the area around Tohoku, hit hard by last’s year tsunami, says Masao Kuwahara at the university there. “Tohoku is a largely undulating region and with many residential areas being relocated to higher ground while workplaces are near the sea, a transport system that relies on gravity is perfectly suited to the topographical conditions,” he says.

Yet, there are those who believe there is still some way to go before the system will be trundled out for real. “In terms of its simplicity and eco-friendliness, I think the idea of using a roller-coaster-like vehicle to transport people is remarkable,” says Takayuki Morikawa at Nagoya University. “However, recently there are trains that are able to regenerate energy when braking or travelling along downhill gradients, so I think it is necessary to scrutinise which of the two is more efficient.”

But for others, the simple fact that they are riding a roller coaster – albeit a slower one – gives Eco-Ride instant glamour.

“Imagine having a roller coaster ride as part of your commute to work,” says sales account manager Yumi Ito, who tried Eco-Ride at a recent open day. “Now that would brighten up your day.”