Fukushima operators begin risky nuclear fuel rod removal
Published time: November 18, 2013
http://rt.com/news/fukushima-start-fuel-removal-883/
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http://www.atimes.com/atimes/Japan/JAP-02-181113.html
TEPCO risks all at Fukushima
By Victor Kotsev
Nov 18, '13
On Monday, by far the most dangerous nuclear operation attempted in
human history was set to begin in the crippled Fukushima Daiichi
power plant in Japan, the removal of more than 1,300 spent fuel rods
and some 200 unused rods from a reservoir on top of Unit 4.
While the undertaking is necessary, the worst-case scenario would
pale in comparison the triple meltdowns of 2011 and necessitate the
evacuation of the capital Tokyo.
Experts are unanimous that the engineering challenges are on a scale
unseen to date, given that the fuel pool was damaged in a fire caused
by a cooling failure and a subsequent explosion during the meltdowns.
If the fuel rods, some of which may be damaged, come too close to
each other, there is a chance that the nuclear chain reaction would
resume, which would be catastrophic in the presence of so much
fissile material, as well as extremely difficult to stop.
If, on the other hand, a fuel rod breaks or is exposed to air and
ignites, this would release into the atmosphere a massive amount of
radiation, likely necessitating the evacuation of the plant. The
total amount of radiation present in the pool is estimated at 14,000
times that released by the atomic bomb dropped at Hiroshima, or about
the same as in the combined cores of the three reactors that melted
down.
"[F]ull release from the Unit-4 spent fuel pool, without any
containment or control, could cause by far the most serious
radiological disaster to date," states The World Nuclear Industry
Status Report 2013, compiled by two independent nuclear energy
consultants. [1]
In several recent interviews with different media, Arnie Gundersen, a
former nuclear industry executive and chief engineer of the
Fairewinds Energy Education non-profit, cautioned that there was no
system to stop a nuclear chain reaction, if one should occur, at the
pool, and recommended that the operators "throw all sorts of boron
into the water" (boron captures neutrons and slows down chain
reactions) before they start pulling the rods out.
"I ran a division that built fuel racks, and these high density fuel
racks like they have at Fuksuhima are very close to going critical
anyway. ... Normally its 0.95, and it can get as high as 0.99; that
means there's a 1% margin before a self-sustaining chain reaction can
occur." [2]
Gundersen said in a separate interview with Radio Ecoshock,
expressing his opinion that the Japanese government rather than Tokyo
Electric Power Company (TEPCO), the plant's operator, should take
charge of the operation: "I suspect come November-December-January we
are going to hear that the building has been evacuated, they broke a
fuel rod, the fuel rod is off-gassing, we have to wait a couple of
days and then go back in." [3]
But even the most vocal critics of TEPCO's and Japan's response to
the crisis so far acknowledge that the fuel has to be removed because
the danger of doing nothing far outweighs the dangers of doing
something wrong.
"If there is another earthquake and building four collapses ... I am
going to evacuate my family from Boston," Dr Helen Caldicott, an
influential Australian anti-nuclear advocate, said during a recent
conference.
While the other exploded buildings hold less nuclear material than
Unit 4, moreover, the challenge of removing molten and spent fuel
from them is far greater. At least some of the reactor cores are
believed to have melted through the containment vessels, and possibly
into the ground, contaminating groundwater with unprecedented levels
of hot particles.
Some of the buildings are off limits to workers due to the deadly
levels of radiation inside, and TEPCO does not even plan to start
working there until a few years to a decade from now. Engineers say
the present undertaking will be a learning experience and a practice
test for that work.
The effort to secure and decontaminate the site has run into numerous
snags recently, with critics claiming mismanagement (a story about
how the Japanese mafia runs many of the low-paid workers at the plant
recently made headlines [4]) and attempts to cover-up the real
severity of the situation. Over the summer, it emerged that the
Pacific Ocean was being continuously contaminated with highly
radioactive groundwater and that some of the hundreds of make-shift
water tanks on site were leaking.
Workers are pumping out some 400 tons of water a day from the reactor
basements and the ground nearby, to a total of almost 500,000 tons at
present stored at the plant, while another 300 tons a day are running
into the ocean. The three molten cores require constant cooling with
water, most of which escapes the breached reactor vessels. To make
matters worse, Fukushima Daiichi is near an ancient river bed at the
base of a hill at the ocean shore, and it is constantly being flooded
with groundwater.
To stem the water flow, TEPCO has announced that it will attempt to
freeze the ground near the plant for up to 100 years in a project
worth hundreds of millions of dollars, but critics say that this will
take years to implement and may not be as reliable as expected.
Efforts to filter the radioactive water in the tanks have also
stalled. [5]
There has been a lot of speculation and few hard facts recently about
ocean contamination, with one of the more esoteric dangers identified
by scientists being that "buckyballs" of uranium fuel could drift all
the way to North America in the next year or so. [6] But though
simulations suggest that radiation from Fukushima would spread across
the entire Pacific in the next few years, scientists also say that it
will be so diluted that no panic is warranted.
Still, there is little ground for optimism either. Even in the
best-case scenario, a major nuclear catastrophe would be averted, but
Fukushima Daiichi would continue to create problems and to pose
deadly threats for decades.
Notes:
1. The World Nuclear Industry Status Report 2013, July 30, 2013.
2. Interview with Fairewinds Chief Engineer Arnie Gundersen, Coast to
Coast AM with John B. Wells, November 9, 2013.
3. Fukushima leaking radiation into Pacific, Radio Ecoshock, September 5, 2013.
4. Special Report: Help wanted in Fukushima: Low pay, high risks and
gangsters, Reuters, October 25, 2013.
5. Factbox: Japan's stalled water filtering system at Fukushima ,
Reuters, September 3, 2013.
6. German researchers say Pacific will dilute Fukushima radiation,
Euractiv, July 17 2012.
Victor Kotsev is a journalist and political analyst.
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