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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