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Wednesday, March 16, 2011

Robots will take over Fukushima Daiichi Plant

Image: Tokyo Electric Power Co's Fukushima Daiich
Japan’s nuclear crisis intensified dramatically on Wednesday after the authorities announced that a second reactor unit at the stricken Fukushima Daiichi plant in northeastern Japan may have ruptured and appeared to be releasing radioactive steam. Tokyo Electric Power, the company operating the reactors had withdrawn most of its workers from the plant on Tuesday, leaving only a skeleton crew of 50 struggling to lower temperatures.

The company says it cannot know for sure what is happening in many cases because it is too dangerous for workers to get close to some reactors. 
So far the highest radiation level measured at Fukushima Daiichi plant was 1,000 mSv/h on March 16, 2011 after smoke rose above the plant and staff were briefly evacuated. When radiation was coming down to 800–600 mSv/h, staff returned. The typical dose near Chernobyl reactor 4 and its fragments, shortly after explosion was ≈ 10 000–300 000 mSv/hr.

Robots will take over at Fukushima Daiichi Plant
Credit: RAD Rover/CMU
The attraction of robots is their potential to work in hazardous environments, thereby reducing the human risks associated with the work. Various robotic systems have helped reduce radiation exposures of inspecting personnel.
Three Mile Island Robots
After the Three Mile Island Unit 2 (TMI-2) nuclear plant disaster in 1979, that destroyed much of the reactor core and left large areas of the reactor containment building inaccessible to humans, several robot prototypes made their debut in the recovery and clean up. William "Red" Whittaker, a robotics professor at Carnegie Mellon University, assembled a team of students in the 1980s to build three robots designed to help inspection and clean up the basement of a damaged reactor at TMI-2. The RAD Rover (1983) was the first vehicle to enter the basement of TMI after the meltdown in March 1979. This vehicle worked four years to survey and clean up the flooded basement. The CoreSampler (1984) drilled core samples from the walls of the Three Mile Island basement to determine the depth and severity of radioactive material that soaked into the concrete at the site.
Nuclear Power Plant Robots in Japan
In Japan general-purpose robots for inspection and maintenance at nuclear power plants have been developed since early 80-ies by Japanese companies such as Toshiba, Hitachi and Mitsubishi. (2)

Chernobyl Disaster Robots 

The Chernobyl disaster in 26 April 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian SSR (now Ukraine), was so far the worst nuclear power plant accident in history, and it is the only one classified as a level 7 event on the International Nuclear Event Scale.

Chernobyl Sarcophagus Robots

At the Chernobyl Nuclear Power Plant robots have been used to study radiation doses on the outer Shelter structure and to examine the remnants of molten radioactive materials. Radiation levels in the area of work is 350 Roentgens per hour, a deadly amount for humans. The robots are developed by the Institute for Safety Problems of NPP, NAS of Ukraine. 

Credit: CMU Pioneer Robot
In 1999 the U.S. government, two universities, and several companies delivered a robot called Pioneer, equipped with three-dimensional vision, radiation detectors, gripping arm, and a bore for taking samples. Pioneer was used to map out the dangerous parts of the defunct, radioactive reactor facility within the aging sarcophagus. The robot was developed by a team again led by prof. William L. "Red" Whittaker, Carnegie Mellon.

Nuclear Decommissioning Robots
According to the World Nuclear Association, WNA, in October 2010 about 100 mines, 80 commercial power reactors, 45 experimental or prototype reactors, over 250 research reactors and a number of fuel cycle facilities, have been retired from operation. Some of these have been fully dismantled. In the UK alone it is estimated that the total cost of dealing with the nuclear legacy is nearly $100Bn. The UK government and the Nuclear Decommissioning Authority (NDA) have developed robots that took over in 2008 from human staff to dismantle the uranium fuel reprocessing plant at Dounreay. The plant was too contaminated with radiation for human workers to carry out the work, so the site turned to specialist demolition firm Brokk to supply the remotely-operated equipment that can work inside cells and a pond. (1)

Applied Robotics for the Power Industry
October 5-7, 2010, the 1st International Conference on Applied Robotics for the Power Industry (CARPI), took place in Montreal, Canada. About 180 experts from robotics solution developers and power industry end-users came together to exchange ideas about about robotics solutions for construction, refurbishment, inspection and maintenance of power systems. The urgent need of nuclear disasters robots was not anticipated but key note speaker, prof. Shigeo Hirose, Tokyo Institute of Technology, talked about snake-like rescue robot "Souryu", arm mounted buggy robot "Gryphon V" for humanitarian demining, quadruped walking robot "TITAN XI" for steep slope construction tasks, and multi-wheeled "Expliner" for the inspection of high-voltage transmission lines. 

Early Warning Signals
According to WikiLeaks files published by The Telegraph, UK, IAEA had warned the Japanese government at a G8 meeting in December 2008 about serious earth quake risks for the Japanese nuclear power plants. 

The Future of the Nuclear Industry - Humans or Robots?
In February 2011 the president of the European Nuclear Society, Prof. Vladimir Slugen, declaired "the greatest risk to the future of the nuclear industry today is a systemic failure to pass on to subsequent generations the vital knowledge that has been acquired over the decades". He says that investment in automatic monitoring and safety control systems has been increasing continuously since the Chernobyl catastrophe. Unfortunately, the same cannot be said for investment in education and training. This failure prevented an optimal transfer of the knowledge that is the life-blood of the nuclear industry. 

Ten Years after Chernobyl
The IAEA booklet Ten Years after Chernobyl: What do we really know? attempts briefly to bring to light what has been learned after ten years of examining the consequences of the Chernobyl accident, reviewing both its immediate and long-term human health and environmental impacts. It is based principally upon the results of an international conference, "One Decade After Chernobyl: Summing Up the Consequences of the Accident," which brought together more than 800 experts from 71 countries in Vienna in April 1996 under sponsorship of the European Commission (EC), the World Health Organization (WHO) and the IAEA.


Tom Levens said...

Excellent blog here! There is a good amount of useful information to be seen here! Thanks for sharing your knowledge!

Tom Levens from Robotics India

Infonaut AB said...

Hi Tom and thanks for visiting Robotland. You might want to check my Global Robotics Brain too
Best regards