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 Last year, Tokyo Electric Power Co said a system meant to purify
contaminated water had failed to remove dangerous radioactive
contaminants.
That means most of that water - stored in 1,000 tanks around the
plant - will need to be reprocessed before it is released into the
ocean, the most likely scenario for disposal.
Reprocessing could take nearly two years and divert personnel and
energy from dismantling the tsunami-wrecked reactors, a project that
will take up to 40 years.
It is unclear how much that would delay decommissioning. But any
delay could be pricey; the government estimated in 2016 that the
total cost of plant dismantling, decontamination of affected areas,
and compensation, would amount to 21.5 trillion yen ($192.5
billion), roughly 20 percent of the country's annual budget.
Tepco is already running out of space to store treated water. And
should another big quake strike, experts say tanks could crack,
unleashing tainted liquid and washing highly radioactive debris into
the ocean.
Fishermen struggling to win back the confidence of consumers are
vehemently opposed to releasing reprocessed water - deemed largely
harmless by Japan's nuclear watchdog, the Nuclear Regulation
Authority (NRA) - into the ocean.
"That would destroy what we've been building over the past eight
years," said Tetsu Nozaki, head of the Fukushima Prefectural
Federation of Fisheries Co-operative Associations. Last year's catch
was just 15 percent of pre-crisis levels, partly because of consumer
reluctance to eat fish caught off Fukushima.
SLOW PROGRESS
On a visit to the wrecked Fukushima Dai-ichi plant last month, huge
cranes hovered over the four reactor buildings that hug the coast.
Workers could be seen atop the No. 3 building getting equipment
ready to lift spent fuel rods out of a storage pool, a process that
could start next month.
In most areas around the plant, workers no longer need to wear face
masks and full body suits to protect against radiation. Only the
reactor buildings or other restricted areas require special
equipment.
Fanning out across the plant's property are enough tanks to fill 400
Olympic-sized swimming pools. Machines called Advanced Liquid
Processing Systems, or ALPS, had treated the water inside them.
Tepco said the equipment could remove all radionuclides except
tritium, a relatively harmless hydrogen isotope that is hard to
separate from water. Tritium-laced water is released into the
environment at nuclear sites around the world.
But after newspaper reports last year questioned the effectiveness
of ALPS-processed water, Tepco acknowledged that strontium-90 and
other radioactive elements remained in many of the tanks.
Tepco said the problems occurred because absorbent materials in the
equipment had not been changed frequently enough.
The utility has promised to re-purify the water if the government
decides that releasing it into the ocean is the best solution. It is
the cheapest of five options a government task force considered in
2016; others included evaporation and burial.
Tepco and the government are now waiting for another panel of
experts to issue recommendations. The head of the panel declined an
interview request. No deadline has been set.
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NRA chief Toyoshi Fuketa believes ocean release after dilution is
the only feasible way to handle the water problem. He has warned
that postponing the decision indefinitely could derail the
decommissioning project.
STORING INDEFINITELY
Another option is to store the water for decades in enormous tanks
normally used for crude oil. The tanks have been tested for
durability, said Yasuro Kawai, a plant engineer and a member of
Citizens' Commission on Nuclear Energy, a group advocating
abandoning nuclear energy.
Each tank holds 100,000 tons, so 10 such tanks could store the
roughly 1 million tons of water processed by ALPS so far, he said.
The commission proposes holding the tritium-laced water, which has a
half life of 12.3 years, in tanks for 123 years. After that, it will
be one thousandth as radioactive as it was when it went into
storage.
Although experts caution that tanks would be vulnerable to major
quakes, Japan's trade and industry minister, Hiroshige Seko, said
the committee would consider them anyway.
"Long-term storage ... has an upside as radiation levels come down
while it is in storage. But there is a risk of leakage," Seko told
Reuters. "It is difficult to hold the water indefinitely, so the
panel will also look into how it should be disposed of eventually."
Space is also a problem, said Akira Ono, Tepco's chief
decommissioning officer. By 2020, the utility will expand tank
storage capacity by 10 percent to 1.37 million tons, and about 95
percent of total capacity will probably be used by the end of that
year, he said.
"Tanks are now being built on flat, elevated spots in stable
locations," Ono said. But such ideal space is getting scarce, he
added.
Many local residents hope Tepco will just keep storing the water. If
it does get released into the ocean, "everyone would sink into
depression," said fishing trawler captain Koichi Matsumoto.
Fukushima was once popular with surfers. But young people in the
area do not go surfing any more because they've been repeatedly
warned about suspected radioactivity in the water, said surf shop
owner Yuichiro Kobayashi.
Releasing treated water from the plant "could end up chasing the
next generation of children away from the sea as well," he said.
Ono says dealing with contaminated water is one of many complex
issues involved in decommissioning.
A year ago, when he took over leading the effort, it felt like the
project had just "entered the trailhead," he said. "Now, it feels
like we're really starting to climb."
(Reporting by Kiyoshi Takenaka; Editing by Malcolm Foster and Gerry
Doyle)
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