Tag Archives: Chernobyl

Nuclear Robots

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Robots have been used in nuclear facilities for a long time.Scenarios such as maintenance tasks in nuclear facilities or even disasters like radioactive leaks or search and rescue operations have proven to be quite successful. We are talking about robotic  arms or remote operated vehicles with some end effectors built in to handle dangerous situations.”

1986: Chernobyl’s robot trouble–During the Chernobyl nuclear incident, the Soviet authorities in charge of cleaning up nuclear waste developed around 60 unique remote-controlled robots to spare human workers from radioactive exposure. The total cost of the clean-up operation was $2bn.  Designs included the STR-1 robot, which resembles a moon buggy. It was placed on the roof of the nuclear plant and used to clean upparts of the destroyed reactor. Another design for the purpose of debris cleaning was the Mobot, developed by Moscow State University. It was a smaller version of a loader used in construction, with a front-end bucket used to  scoop up debris.

The problem was that cleaning up nuclear waste required more skills than the robots could provide, eventually resulting in the authorities sending in soldiers to perform most of the decontamination works. Radiation was so high that each worker could only spend 40 seconds inside or near the facility; 31 died from exposure, while 237 suffered from acute radiation sickness.

2008: Cleaning up nuclear waste at Hanford Nuclear Reservation. The Hanford Nuclear Reservation in the US has been somewhat of a hub for nuclear waste innovation. This is because scientists, and their robot friends, are faced with the task of emptying nuclear and chemical waste tanks the size of around 150 basketball courts before the waste reaches the Columbia River. Exposure to the material would kill a human instantly.

Luckily, Hanford has developed a few automated machines thatare specifically designed for different parts of the job. Take Foldtrack, for example, which can access the tanks through one-foot-wide pipes in the roof bysplitting into a string of pieces, and then rebuilding itself like a Transformer once inside. The remote-controlled robot uses a 3,000psi water cannon to blast nuclear sludge off the walls of the tank and pump it out. Upon completion, scientists are forced to leave the $500,000 robot in the tank due to the high levels of contamination.

  • sand mantis
  • tank crawler
  • Sunfish
  • foldtrack

Another robot, the Sand Mantis, looks like a fire hose on wheels. However, it comes packed with power, with the ability to blast tough toxic salts that build up in waste tanks with its 35,000psi water cannon. For comparison, a regular firehose has around 300psi of pressure. In order to support the huge power, the orifice of the hose is made of gems, such as sapphires, which can withstand the pressure….Finally, the Tandem Synthetic Aperture Focusing Technique,or Tank Crawler, locates cracks or corrosion in Hanford’s waste storage tanks using ultrasonic and electrical conductivity sensors.

2011: Fukushima—Previously designed robots failed to visually inspect the reactor, either breaking due to high radiation or by getting stuck in the confined spaces. That was until Toshiba’s senior scientist in its technology division, Kenji Matsuzaki, developed the Little Sunfish – an amphibious bread loaf-sized robot that could slip into the 5.5-inch reactor pipelines.

In 2017,  the Sellafield nuclear site in the UK, scientists have been working on methods to clean up the vast amounts of nuclear sludge from its First-Generation Magnox Storage Pond, as part of decommissioning efforts said to cost around £1.9bn each year. The size of two Olympic swimming pools, the storage pond contains large amounts of nuclear sludge from decaying fuel rods stored below the surface.  While robots have been designed to reach the depths of the pond and remove nuclear waste, none proved to be very successful, until Cthulhu– Collaborative Technology Hardened for Underwater and Littoral Hazardous Environment.  Cthulhu is a tracked robot that can move along the bottom ofthe storage pond, using whisker-like sensors and sonar to identify and retrieve the nuclear rods.

2018:  The South West Nuclear Hub at the University of Bristol inthe UK is collaborating with Sellafield to develop a nuclear waste robotic suit for humans, taking inspiration from the comic book hero Iron Man.

Excepts from Cherno-bots to Iron Man suits: the development of nuclear waste robotics,, Power-Technology. com, Dec. 4, 2018

How to Clean Radioactive Water

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Russia’s nuclear energy giant Rosatom’s subsidiary RosRAO has created a prototype water decontamination plant for use at Tokyo Electric Power Co. Holdings’ Fukushima Daiichi nuclear power station — the site of Japan’s largest nuclear disaster in March 2011. The scrubbing facility, unveiled in June 2014, is capable of removing tritium, or radioactive hydrogen, from nuclear-tainted water, something beyond the capabilities of the Fukushima plant’s current cleanup equipment. Distillation and electrolysis isolate and concentrate the isotope, which is then locked away in titanium. Experiments under conditions similar to those on the ground reportedly show the technology cutting wastewater’s radioactive material content to one-6,000th the initial level, making it safe for human consumption or release into the ocean.

Duplicating the facility near the Fukushima site and running it for the five years necessary to process 800,000 cu. meters of contaminated water would cost around $700 million in all. Companies in Japan and the U.S. are at work on their own facilities for tritium disposal, but the Russian plan’s cost and technological capability make it fully competitive, according to the project’s chief.

Rosatom has made other overtures to Japan. Executives from a mining and chemical unit have visited several times this year for talks with Japanese nuclear companies, aiming to cooperate on decommissioning the Fukushima plant and upgrading a reprocessing plant in Aomori Prefecture for spent nuclear fuel. Russia has amassed a wealth of expertise dealing with damaged nuclear reactors in the wake of the Chernobyl disaster, and would like Japan to draw on that knowledge, the subsidiary’s chief executive said.

Revving up nuclear technology exports is essential to re-energizing Russia’s domestic industry and breaking free of dependence on the resource sector, Moscow has decided. The nuclear business, along with the space industry, is one of the few tech-intensive sectors where the country is internationally competitive. President Vladimir Putin has leaned more heavily on leaders in Europe and emerging countries in recent years to agree to deals with Russia’s nuclear companies.

In Japan, the public has grown wary of nuclear energy since the accident, leaving demand for new plants in the country at next to nil. Yet Japan has more than 10 reactors slated for decommissioning, creating a market worth up to 1 trillion yen ($9.42 billion) by some calculations. Russia aims to use cooperation on the Fukushima plant to crack the broader market and grow its influence, a source at a French nuclear energy company said…

But Japanese Prime Minister Shinzo Abe nevertheless visited Russia in May 2016 for top-level talks despite U.S. objections, eager to make progress on territorial disputes over islands north of Hokkaido. Preparation is underway for another summit in the far-eastern city of Vladivostok in September 2016, as well as a visit by Putin to Japan before the year is out.
Excerpts from TAKAYUKI TANAKA, Japan nuclear cleanup next target in Russian economic offensive, Nikkei Asian Review, July 24, 2016

 

Chernobyl Nuclear Accident: 1986 to 2016

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A workforce of around 2,500 people is finishing a massive steel enclosure that will cover Chernobyl’s reactor 4, where the radioactive innards of the nuclear plant are encased in a concrete sarcophagus hastily built after the disaster.  If all goes to plan, the new structure—an arch more than 350 feet high and 500 feet long—will be slid into place late next year over the damaged reactor and its nuclear fuel, creating a leak-tight barrier designed to contain radioactive substances for at least the next 100 years.

The project, known as the New Safe Confinement,  is a feat of engineering.  [see also the Chernobyl Gallery] It will take two or three days to slide the 36,000-ton structure into place. The arch, which looks something like a dirigible hangar, is large enough to cover a dozen football fields. “You could put Wembley Stadium underneath here, with all the car parks,” said David Driscoll, the chief safety officer for the French consortium running the construction site.

Three decades ago, an army of workers scrambled to build a concrete sarcophagus around Chernobyl Reactor 4, which released a radioactive plume after a reactor fire and explosion on April 26, 1986.  At least 30 people died as an immediate result of the accident, which contaminated parts of Ukraine, Belarus and Russia and sent radioactive dust and debris over Europe. Pripyat, the company town of 50,000, was completely evacuated.

Emergency workers and evacuees received doses of radiation significantly above natural background levels, according to the World Health Organization. Researchers acknowledge high levels of thyroid cancer among people who were children at the time of the accident, from exposure to radioactive iodine…

Nicolas Caille, project director for Novarka, the consortium of Vinci SA and Bouygues SA, the French contractors running the project, said about 1,000 people work on a typical shift at the construction site, keeping to a schedule of 15 days in and 15 out….

A new facility to safely and securely store spent nuclear rods is being built at the nuclear power complex. The Interim Spent Fuel Storage Facility, or ISF2, is intended to store spent fuel rods for a minium of 100 years…..The Liquid Radioactive Waste Treatment Plant in Chernobyl…retrieves highly active liquids from their current tanks, processes them into a solid state and moves them to containers for long-term storage. …

Wildlife has flourished in the forest [surrounding Chernobyl], which is largely off limits to humans. Officials say species such as lynx, wild boar, wolves, elk, bear and European bison have rebounded.

Excerpts from Nathan Hodge, 30 Years After Chernobyl Disaster, an Arch Rises to Seal Melted Reactor, Wall Street Journal, Apr. 25, 2016

Nuclear Waste: Ukraine

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A consortium of four German companies has been awarded a contract to improve infrastructure for managing radioactive waste, the rehabilitation of contaminated areas and the decommissioning of nuclear power plants in Ukraine.  The consortium – comprising Brenk Systemplanung, DMT, Plejades and TÜV Nord EnSys – was awarded the contract for the project, which is within the framework of the European Union-funded Instrument for Nuclear Safety Cooperation (INSC). The INSC is designed to support non-EU countries in improving nuclear safety. The contract will run for an initial two-year period and have a maximum budget of €1.5 million ($1.6 million).

According to the tender notice, the main objectives of the contract are to support the Ukrainian State Corporation ‘Radon’ in establishing an emergency response system for “radiation incidents involving unauthorized radioactive materials that are not related to nuclear power plant operation”. It also calls for the establishment of integrated, automated monitoring systems for radiation and environmental protection at Radon facilities, as well as the remediation of radioactive waste storage sites resulting from the Chernobyl nuclear power plant accident and situated outside the exclusion zone.

In a statement yesterday, DMT said it will jointly lead with TÜV Nord EnSys Hannover the assessment of some 50 radioactive waste storage sites.

Excerpts from German consortium awarded Ukrainian waste contract, World Nuclear News, Mar. 2, 2016

Population Resettlement at Fukushima: who dares?

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By the time Fukushima prefecture finishes the task of decontaminating houses and farmland around the Dai-ichi plant, it will have spent an estimated $50 billion on the work.  Some argue it would have been wiser to have spent the money on resettling former residents elsewhere. Already many of the 80,000 or so people displaced from the areas around the plant have begun new lives. Those moving back are mainly elderly. Local officials expect that half of the evacuees, especially those with children who are more vulnerable to radiation, may never return.

Fear of radiation, and distrust of data from the government and from the Tokyo Electric Power Company (TEPCO), the Dai-ichi operator, on the risk it poses, are the biggest reasons. On October 20th, 2015 it was announced that a worker who had helped to contain the accident had developed cancer linked to the meltdown. It was the first such diagnosis, but a recent medical study found a huge leap in cases of thyroid cancer among children and adolescents in Fukushima prefecture since the catastrophe.

Public faith in Japan’s institutions suffered a severe blow as a result of the government’s bungled response to the accident in 2011. So when officials of Tamura city wanted to open the Miyakoji district in 2013, residents resisted and demanded more decontamination work.

A year after the lifting of the evacuation order on his village, Yuko Endo, the mayor of Kawauchi, says distrust is so widespread that he doubts his community will return even near to its former size. But he has visited the area around Chernobyl in Ukraine, the site of the world’s worst nuclear disaster 29 years ago. He says the sight there of abandoned villages resembling graveyards has stiffened his resolve to rebuild. Those who have now returned are still deeply sceptical about the assurances they receive. Many ask why, for instance, if the soil is safe, they must take their locally grown produce to be checked for radiation.

There is a particular ray of hope in Naraha—more of one than is evident in Miyakoji and Kawauchi. The town will benefit from jobs related to the decommissioning of the nearby nuclear plants, including Dai-ni, which got through the earthquake and tsunami relatively unscathed. Another of Naraha’s immediate projects is to erect new streetlights. It will be helped by dollops of government aid. Mr Matsumoto, the mayor, talks of luring people back by making his town much more attractive than it was before. But for now, many streetlights do not even work. It is dark at night and the atmosphere is eerie.

Nuclear Power in Japan: Back to the Nuclear Zone, Economist, Oct. 24, 2015, at 39

Nuclear Accidents of the Future

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Three major atomic accidents [Three Mile Island US 1979, Chernobyl USSR 1986, Fukushima Japan 2011] in 35 years are forcing the world’s nuclear industry to stop imagining it can prevent more catastrophes and to focus instead on how to contain them.  As countries such as China and India embrace atomic power even after the Fukushima reactor meltdowns in 2011 caused mass evacuations because of radiation fallout, scientists warn the next nuclear accident is waiting to happen and could be in a country with little experience to deal with it.

“The cold truth is that, no matter what you do on the technological improvements side, accidents will occur — somewhere, someplace,” said Joonhong Ahn, a professor at the Department of Nuclear Engineering of University of California, Berkeley. The consequences of radiation release, contamination and evacuation of people is “clear and obvious,” Ahn said. That means governments and citizens should be prepared, not just nuclear utilities, he said.

While atomic power has fallen from favor in some western European countries since the Fukushima accident — Germany, for example, is shutting all of its nuclear plants — it’s gaining more traction in Asia as an alternative to coal. China has 28 reactors under construction, while Russia, India, and South Korea are building 21 more, according to the World Nuclear Association. Of the 176 reactors planned, 86 are in nations that had no nuclear plants 20 years ago, WNA data show…

The problem is that the causes of the three events followed no pattern, and the inability to immediately contain them escalated the episodes into global disasters with huge economic, environmental and political consequences. Even if no deaths have yet been officially linked to Fukushima radiation, for example, cleanup costs have soared to an estimated $196 billion and could take more than four decades to complete.

If nuclear is to remain a part of the world’s energy supply, the industry must come up with solutions to make sure contamination — and all other consequences — do not spread beyond station grounds, Gregory Jaczko, ex-chairman of the U.S. Nuclear Regulatory Commission, said in an interview in Tokyo….

Since the introduction of nuclear stations in the 1950s, the industry has focused safety efforts on design and planning. Research and innovation has looked at back-up systems, passive technology that would react even if no human operator did, and strengthened materials used in construction of atomic stations….

The official toll from the reactor explosion at Chernobyl was put at 31 deaths. Radiation clean-up work, however, involved about 600,000 people, while 200,000 locals had to be relocated.  The accident contaminated 150,000 kilometers of land and according to the last Soviet leader Mikhail Gorbachev it was a factor in bringing about the collapse of the Soviet Union in 1991.

In Japan, the meltdown of three Fukushima reactors helped unseat premier Naoto Kan and forced the evacuation of about 160,000 people, destroying local fishing, farming and tourism industries along the way. It also brought tens of thousands of anti-nuclear protesters out onto the streets in the country’s biggest demonstrations since the 1960s. Tokyo Electric Power Co., the plant operator and once the world’s biggest non-state power producer, would have been bankrupted by the Fukushima accident but for billions of dollars in government aid…

Building a plant that would contain an accident within the facility boils down to cold cash, he said.  The review calls for new reactor designs to make a major release of radioactive fallout outside the station site “practically impossible,” the IAEA said. The standard would be “crucial for public acceptance and for the sustainability of nuclear energy.” Specialists on the review met for the first time in March and no conclusions are yet available, IAEA spokesman Greg Webb said by e-mail.

The problem with an engineering solution, an ever better reactor design or grander safety systems, is that based on the premise that all technology is fallible those defense systems can also fail, Berkley’s Ahn said.  “This is an endless cycle,” Ahn said. “Whatever is your technology, however it is developed, we always have residual risk.”  When the next nuclear accident occurs the world needs to have better knowledge of how to limit the spread of radiation and do the clean-up, including removing radiation from the soil, water and having an efficient evacuation drill for the population in danger zones, Ahn said. We also need more understanding of the impact of low-dose radiation on organisms, he said.  “This is about recovery from an accident, not preventing an accident,” Ahn said. “It’s completely different. And I think this concept is very necessary for the future of nuclear utilization.”

Excerpts from Yuriy Humber, World Needs to Get Ready for the Next Nuclear Plant Accident, Bloomberg, Apr. 4, 2014