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Monday, February 1, 2016

first robot sent to radioactive Fukushima plant dies in 3 hours !!!

The land of rising Sun, an archipelago of  6852 islands was  in the news for wrong seasons after surviving the natural disasters of largest earthquake on March 11, 2011,  measuring 9.0 and spawning of a deadly Tsunami after.  Car, ships and building were swept away by a wall of water and the country  had to count its dead. Sendai, a port city was worst affected.  

The World cannot forget  the Fukushima nuclear disaster – Fukushima, strangely means ‘good fortune island’ lies about 250 km north of Tokyo and 80 km south of Sendai, known for nuclear power plants.  The plants have boiling water reactors, a part of which had been shut down for maintenance.  The remaining reactors were shut down after the earthquake but tsunami flooded the plant knocking the emergency reactors required to run pumps which cool and control the reactors.  The earthquake in its wake prevented assistance reaching in time.    The plant began releasing substantial amounts of radioactive material becoming the largest nuclear incident since the Chernobyl disaster in April 1986 and the second (after Chernobyl) to measure Level 7 on the International Nuclear Event Scale.

Even after  the natural disasters struck, the crowds were orderly and calm.  In disaster films, you  see heroes who would remain stoic, undaunted, committed to the cause, facing adversity sacrificing themselves for the cause.  Japan is fortunate to have some such heroes which included  workers, emergency service personnel and scientists battling to save the Fukushima nuclear plant, their fellow citizens and themselves.

According to World Nuclear.org  - the  accident was rated 7 on the INES scale, due to high radioactive releases over days 4 to 6, eventually a total of some 940 PBq (I-131 eq).  Four reactors were written off due to damage in the accident.  Apart from cooling, the basic ongoing task was to prevent release of radioactive materials, particularly in contaminated water leaked from the three units. This task became newsworthy in August 2013.  There have been no deaths or cases of radiation sickness from the nuclear accident, but over 100,000 people had to be evacuated from their homes to ensure this. Government nervousness delays their return.

Now years after the accident, refugees living in temporary housing do not expect to return to their homes. Scientists and radiation specialists do not expect the land to be free from danger any time soon.  There are some suggestions quoting experts that the desolate landscape of collapsed homes and abandoned convenience stores  are not expected  to be liveable again within the next few decades.  If it is out-of-bound, for humans, researchers would try animals and robots ..... MailOnline reports that the first  robot sent inside melted reactor at tsunami-hit plant died after just three hours - but not before sending back chilling pictures – some excerpts of that newsitem below :

The first robot to be sent into the radioactive reactor of Fukushima nuclear power plant has stalled just three hours into its mission.  The incredible pictures sent by it offered  the first glimpse into the melted reactors at the Japanese plant after the 2011 nuclear disaster. The photographs were captured as part of the robot's mission to inspect melted fuel in one of the reactors.  Developed by Hitachi-GE Nuclear Energy and the International Research Institute for Nuclear Decommissioning, it was supposed to be able to function for about 10 hours at levels of radiation which would be fatal to humans and cause ordinary electronic devices to malfunction.

But decommissioning work at the plant suffered a setback after the adaptable 'transformer' robot stalled before it could complete its operation and had to be abandoned. A second robot mission was postponed as engineers investigated the cause of the malfunction.  The Tokyo Electric Power Company, which operates the wrecked Fukushima nuclear plant, admitted the robot had only completed two-thirds of Friday's planned mission inside the Unit 1 containment vessel before it failed.But the company said it had collected enough data to indicate there was path to send robots deeper into the reactor.  It leaves the door open to a new generation of remote-controlled robot missions which may finally reveal the residue of the melted fuel for the first time since the 2011 disaster.

TEPCO spokesman Teruaki Kobayashi said the robot sufficiently collected temperature, radiation levels and images from parts of the platform just below the reactor core's bottom by the time it got stuck and became unrecoverable. Mr Kobayashi said the test also showed the robot tolerated radiation and that the radiation levels were significantly lower than anticipated. That means robots can last longer and some wireless device may even be usable, even though the radiation levels were way too high for humans to enter the area, even wearing protective gear.   The Clean-up is  expected to take decades, and cost more than £18 billion.

TEPCO plans to send in a different, amphibious robot next year for further investigation of the three reactors that suffered meltdowns. Computer simulation and cosmic ray examinations have shown that almost all fuel rods in the Unit 1 reactor have melted, breached the core and are now lying at the bottom of the containment chamber.  The nuclear plant is still being taken apart, and it is estimated it will take decades to make the area safe, as well as cost billions of pounds.  With soil and water contaminated, nobody can live there yet, and it is unknown when the clean-up mission will be completed.

With regards – S. Sampathkumar

12th May 2015.

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