Clean up at Fukushima will take decades

Cleaning up Japan's radioactive 

water could take decades

No one is sure how to safely dispose of millions 

of gallons of highly radioactive water at the 

Fukushima Daiichi nuclear plant. 'There is 

nothing like this, on this scale, that we have 

ever attempted to do before,' a U.S. expert says.

By Julie Makinen and Ralph Vartabedian, Los Angeles Times, April 7, 2011
Reporting from Tokyo and Los Angeles

For nearly four weeks, Japanese emergency crews have been spraying 
water on the damaged Fukushima Daiichi nuclear reactors, a desperate 
attempt to avert the calamity of a full meltdown.


Now, that improvised solution to one nuclear nightmare is spawning 
another: what to do with the millions of gallons of water that has become 
highly radioactive as it washes through the plant.


The water being used to try to cool the reactors and the dangerous spent 
fuel rods is leaking through fissures inside the plant, seeping down through 
tunnels and passageways to the lowest levels, where it is accumulating into 
a sea of lethal waste.


No one is sure how to get rid of it safely.


"There is nothing like this, on this scale, that we have ever attempted to do 
before," says Robert Alvarez, a former assistant secretary of the U.S. 
Energy Department.


Japanese officials estimate that they already have accumulated about 15 
million gallons of highly radioactive water. Hundreds of thousands of gallons 
are being added every day as the plant's operator, the Tokyo Electric Power 
Co., continues to feed coolant into the leaky structures.


Ultimately, the high-level radioactive substances in the water will have to be 
safely stored, processed and solidified, a job that experts say will almost 
certainly have to be handled on a specially designed industrial complex. 
The process of cleaning up the water could take many years, even decades, 
to complete. The cost could run into the tens of billions of dollars.



Victor Gilinsky, a former member of the Nuclear Regulatory Commission 
and longtime advisor on nuclear waste, said the problems facing Japan 
are greater than even the most highly contaminated nuclear weapons 
site in the U.S., the Hanford Nuclear Reservation in Washington state.


The Department of Energy is decommissioning eight reactors at Hanford 
and plans to process about 58 million gallons of radioactive sludge now in 
leaky underground tanks, all at an estimated cost of $100 billion to $130 
billion, according to outside estimates. But unlike Fukushima Daiichi, none 
of the Hanford reactors melted down and virtually all of the site is accessible
to workers without risking exposure to dangerous levels of radioactivity.


"It will be a big job, bigger than Hanford," Gilinsky said, though he cautioned 
that U.S. costs are unnecessarily high and that the Japanese may be able 
to do the work more economically.


The immediate problem facing the Japanese is how to store all that water 
until the reactors and the spent fuel pools are brought under control. The 
plant's main storage tanks are nearly full. To make room, Tokyo Electric 
Power, known as Tepco, released a couple of million gallons of the least 
contaminated water into the ocean this week, with the expectation that its 
radioactive elements would be diluted in the ocean's mass.


But international law forbids Japan from dumping contaminated water into 
the ocean if there are viable technical solutions available down the road.


So Tepco is considering bringing in barges and tanks, including a 
"megafloat" that can hold about 2.5 million gallons. Japan has also 
reportedly asked Russia to send a floating radiation treatment plant called 
the Suzuran that was used to decommission Russian nuclear submarines 
in the Pacific port of Vladivostok. The Suzuran was built in Japan a 
decade ago.


Yet even using barges and tanks to temporarily handle the water creates 
a future problem of how to dispose of the contaminated vessels.


U.S. and Japanese experts say the key to solving the disposal problem 
involves reducing the volume of water by concentrating the radioactive 
elements so they can be solidified into a safer, dry form. But waste 
experts disagree on exactly how to do that.


The difficulty of concentrating and then solidifying the contaminants 
depends on how much radioactivity is in the water, the type of isotopes 
and whether the work can be done on the Fukushima site.


UC Berkeley nuclear engineering professor Edward Morse said the water 
needs to be diverted into a concrete-lined holding pond fairly soon, 
where natural evaporation can help reduce its volume.


Youichi Enokida, a specialist in nuclear chemical engineering at Nagoya 
University in Japan, agrees that the material should be put into some 
type of storage that would concentrate it through evaporation, though 
Japanese experts generally talk about the need for a sealed pool.


"We must concentrate the liquid," he said.


Even with a pond, it could take up to 10 years before the radioactivity 
would decay enough for the material to be handled, Morse said. Building 
a storage pond "buys you time," he said.


But other experts sharply disagree, saying exposing the material to open 
air could allow radioactive iodine and other volatile substances to blow 
off the site, adding to the remote contamination that is already spreading 
dozens of miles from the plant.


A factor that could vastly complicate the problem is the presence of 
tritium, or heavy water, which is produced during fission. Tritium cannot 
be filtered out of water, instead requiring an extremely expensive 
treatment process.


[CORRECTION: Tritium (radioactive hydrogen) is NOT the same thing as
heavy water (which is not radioactive).  Ordinary hydrogen is denoted 
by the letter H.  Heavy hydrogen, though twice as heavy as ordinary 
hydrogen, is NOT radioactive.  It is called deuterium and is denoted by 
the letter D.  When water molecules (H2O) are made with heavy hydrogen 
atoms, you have "heavy water" (D2O) which is not radioactive. Tritium, 
however, is THREE times as heavy as ordinary hydrogen; it is denoted 
by the letter T.  And tritium is radioactive, with a half-life of 13 years, so 
it lasts for a century or more in the environment.  Tritium gives off a very 
weak beta radiation which has little penetrating power, and is therefore 
(a) difficult to detect and (b) not harmful outside the body -- but tritium 
can be very dangerous inside the body, because it freely exchanges with 
ordinary (non-radioactive) hydrogen in all of our organic molecules, 
including our DNA molecules.  It enters freely into all living things,
and it CANNOT be filtered out of ordinary water. (GE) ]


"If the contaminated water has relatively high tritium or tritiated water 
concentration, then treatment could be more complicated," said Joonhong 
Ahn, a nuclear waste expert at UC Berkeley.


Nuclear power plants normally have systems in place to treat tritium on 
site. But the condition and capacity of the Fukushima system is not known.


Enokida and Morse contend that if the water can be concentrated, it can 
then be put into dry form or even turned into glass, as is planned at 
Hanford and other contaminated sites around the world. But this process, 
called vitrification, is expensive and requires a small-scale industrial 
facility.


The alternative — processing the waste elsewhere in Japan — is likely 
to be controversial.


"The fishermen will protest; this is inevitable," Enokida said.


Morse said that the plant faces at least six months of emergency 
stabilization, about two years of temporary remediation and anywhere 
from two years to 30 years of full-scale cleanup. Furthermore, the high 
levels of ground contamination at the site are raising concerns about 
the viability of people working at the site in coming decades.


It will take hundreds or even thousands of workers years or decades to 
handle the cleanup, experts said.


U.S. officials have not yet discussed the water management problems 
with their Japanese counterparts. But Nuclear Regulatory Commission 
spokesman Scott Burnell said the nuclear industry has a long 
experience with filtering radioactive contamination out of water, though 
never at a plant that has suffered such damage. At Three Mile Island it 
was decided to allow the tritium-contaminated water to evaporate, 
though that meant the tritium escaped as well.


At some point, however, Japan will have to add facilities to existing 
treatment plants in order to vitrify the radioactive material into glass 
logs or other dry forms that could be stored in alloy canisters. Those 
logs or canisters would have to be buried somewhere.


Where that burial ground is built is a question that the Japanese are 
only beginning to consider.


julie.makinen@latimes.com

ralph.vartabedian@latimes.com

Makinen reported from Tokyo and Vartabedian from Los Angeles.