Where to put Fukushima's
radioactive water?
'Our land is limited and we
would eventually run out of storage space,' manager says
TOKYO — Japan's crippled nuclear power plant is
struggling to find space to store tens of thousands of tons of
highly contaminated water used to cool the broken reactors, the
manager of the water treatment team said.
About 200,000 tons of radioactive water — enough to fill more
than 50 Olympic-sized swimming pools — are being stored in
hundreds of gigantic tanks built around the Fukushima Dai-ichi
plant. Operator Tokyo Electric Power Co. has already chopped
down trees to make room for more tanks and predicts the volume
of water will more than triple within three years.
"It's a pressing issue because our land is limited and we
would eventually run out of storage space," the water-treatment
manager, Yuichi Okamura, told The Associated Press in an
exclusive interview this week.
TEPCO is close to running a new treatment system that could
make the water safe enough to release into the ocean. But in the
meantime its tanks are filling up — mostly because leaks in
reactor facilities are allowing ground water pour in.
Outside experts worry that if contaminated water is released,
there will be lasting impact on the environment. And they fear
that because of the reactor leaks and water flowing from one
part of the plant to another, that may already be happening.
Nuclear engineer and college lecturer Masashi Goto said the
contaminated water buildup poses a long-term health and
environmental threat. He worries that the radioactive water in
the basements may already be getting into the underground water
system, where it could reach far beyond the plant, possibly the
ocean or public water supplies.
"You never know where it's leaking out and once it's out you
can never put it back in place," he said. "It's just outrageous
and shows how big a disaster the accident is."
The concerns are less severe than the nightmare scenario TEPCO faced
in the weeks after the March 11, 2011, earthquake and tsunami knocked
out power and cooling systems at the plant, leading to explosions and
meltdowns of three reactor cores in the world's worst nuclear disaster
since Chernobyl. The plant released radiation into the surrounding air,
soil and ocean and displaced more than 100,000 residents who are
uncertain when — or if — they will be able to return to their homes.
Dumping massive amounts of water into the melting reactors was the only
way to avoid an even bigger catastrophe.
Okamura remembers frantically trying to find a way to get water to spent
fuel pools located on the highest floor of the 50-meter-high reactor
buildings. Without water, the spent fuel likely would have overheated
and melted, sending radioactive smoke for miles and affecting possibly
millions of people.
"The water would keep evaporating, and the pools would have dried up if
we had left them alone," he said. "That would have been the end of it."
Attempts to dump water from helicopters were ineffective. Spraying
water from fire trucks into the pools didn't work either. Okamura then
helped bring in a huge, German-made concrete-making pump with a
remote-controlled arm that was long enough to spray water into the fuel
pools.
The plan worked — just in time, Okamura said.
Those measures and others helped bring the plant under tenuous control,
but it will take decades to clean up the radioactive material. And those
desperate steps created another huge headache for the utility: What to
do with all that radioactive water that leaked out of the damaged
reactors and collected in the basements of reactor buildings and nearby
facilities.
Some of the water ran into the ocean, raising concerns about
contamination of marine life and seafood. Waters within a 20-kilometer
(12-mile) zone are still off-limits, and high levels of contamination
have been found in seabed sediment and fish tested in the area.
Okamura was tasked with setting up a treatment system that would make
the water clean enough for reuse as a coolant, and was also aimed at
reducing health risks for workers and environmental damage.
At first, the utility shunted the tainted water into existing storage
tanks near the reactors. Meanwhile, Okamura's 55-member team scrambled
to get a treatment unit up and running within three months of the
accident — a project that would normally take about two years, he said.
"Accomplishing that was a miracle," he said, adding that a cheer went up
from his men when the first unit started working.
Using that equipment, TEPCO was able to circulate reprocessed water back
into the reactor cores. But even though the reactors now are being
cooled exclusively with recycled water, the volume of contaminated water
is still increasing, mostly because ground water is seeping through
cracks into the reactor and turbine basements.
Next month, Okamura's group plans to flip the switch on new purifying
equipment using Toshiba Corp. technology that is supposedly able to
decontaminate the water by removing strontium and other nuclides,
potentially below detectable levels, he said.
TEPCO claims the treated water from this new system is clean enough to
be potentially released into the ocean, although it hasn't said whether
it would do that. Doing so would require the permission of authorities
and local consent and would also likely trigger harsh criticism at home
and abroad.
To deal with the excess tainted water, the utility has channeled it to
more than 300 huge storage tanks placed around the plant. The utility
has plans to install storage tanks for up to 700,000 tons — or about
three more years' worth — of contaminated water. If that maxes out, it
could build additional space for roughly two more years' worth of
storage, said Mayumi Yoshida, a company spokeswoman.
But those forecasts hinge on plans to detect and plug holes in the
damaged reactors to minimize leaks over the next two years. The utility
also plans to take steps to keep ground water from seeping into the
reactor basements.
Both are tasks that TEPCO is still not sure how to accomplish: Those
areas remain so highly radioactive that it is unclear how humans or even
robots could work there.
There's also a risk the storage tanks and the jury-rigged pipe system
connecting them
© 2012 NBCNews.com
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