The Washington Post:
” FUTABA, Japan — Seen from the road below, the Fukushima Daiichi nuclear power station looks much as it may have right after the catastrophic earthquake and tsunami that caused a triple meltdown here almost five years ago.
The No. 3 reactor building, which exploded in a hydrogen fireball during the disaster, remains a tangle of broken concrete and twisted metal. A smashed crane sits exactly where it was on March 11, 2011. To the side of the reactor units, a building that once housed boilers stands open to the shore, its rusted, warped tanks exposed.
The scene is a testament to the chaos that was unleashed when the tsunami engulfed these buildings, triggering the world’s worst nuclear disaster since the one at Chernobyl, in Ukraine, in 1986. Almost 16,000 people were killed along Japan’s northeastern coast in the tsunami, and 160,000 more lost their homes and livelihoods.
Tokyo Electric Power Co. (Tepco), the utility company that runs the Fukushima plant and drew fierce criticism for its handling of the disaster, says the situation has improved greatly.
“In the last five years, radiation levels have been reduced substantially, and we can say that the plant is stable now,” said Akira Ono, the Tepco plant superintendent.
Efforts to contain the contamination have progressed, according to Tepco, including the completion Tuesday of a subterranean “ice wall” around the plant that, once operational, is meant to freeze the ground and stop leakage. Moves to decommission the plant — a process that could take 30 or 40 years, Ono estimated — are getting underway.
People will be allowed to return to their homes in the nearby town of Naraha next month and to Tomioka, even closer to the plant, next year. For now, Tomioka and neighboring Okuma remain ghost towns, lined with convenience stores, fast-food restaurants and gambling parlors that haven’t had a customer in five years. Bicycles lean near front doors, and flowerpots sit empty on windowsills.
A sign on the road to the plant showed a radiation reading of 3.37 microsieverts per hour, at the upper end of safe. At a viewing spot overlooking the reactor buildings, it shot past 200, a level at which prolonged exposure could be dangerous. Both readings are hundreds of times lower than they were a couple of years ago.
After about 20 minutes at the viewing spot, a Tepco official bustled visiting reporters, wearing protective suits, onto a bus. “We don’t want you out here too long,” he said. Below, men continued working on the site.
But one huge question remains: What is to be done with all the radioactive material?
There’s the groundwater that is flowing into the reactor buildings, where it becomes contaminated. It has been treated — Tepco says it can remove 62 nuclides from the water, including strontium, which can burrow into bones and irradiate tissue. It cannot filter out tritium, a radioactive isotope of hydrogen that can be used to make nuclear bombs but is not considered especially harmful to humans.
The water initially was stored in huge bolted tanks in the aftermath of the disaster, but the tanks have leaked highly contaminated radioactive water into the sea on an alarming number of occasions.
Now Tepco is building more-secure welded tanks to hold the water, theoretically for up to 20 years. There are now about 1,000 tanks holding 750,000 tons of contaminated water, with space for 100,000 tons more. The company says it hopes to increase capacity to 950,000 tons within a year or two, as well as halve the amount of water that needs to be stored from the current 300 tons per day.
As part of those efforts, Tepco built the 1,500-yard-long ice wall around the four reactor buildings to freeze the soil and keep groundwater from getting in and becoming radioactive. Company officials hoped to have the wall working next month; on Wednesday, however, Japan’s nuclear watchdog blocked the plan, saying the risk of leakage was still too high.
The options for getting rid of the contaminated water include trying to remove the tritium from it before letting it run into the sea; evaporating it, as was done at Three Mile Island, the Pennsylvania plant that melted down in 1979; and injecting it deep into the ground, using technology similar to that used to extract shale gas. A government task force is considering which option to choose. ”
by Anna Fifield
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” Tokyo (CNN) — Cleaning up Japan’s Fukushima Daiichi nuclear plant, which suffered catastrophic meltdowns after an earthquake and tsunami hit in 2011, may take up to 40 years.
The crippled nuclear reactor is now stable but the decommissioning process is making slow progress, says the plant’s operator Tokyo Electric Power Co, better known as TEPCO.
“If I may put this in terms of mountain climbing, we’ve just passed the first station on a mountain of 10 stations,” said Akira Ono, head of the Fukushima plant.
It’s almost five years since the earthquake and the tsunami it triggered killed more than 15,000 people and destroyed coastal towns on March 11, 2011.
TEPCO has attracted fierce criticism for its handling of the disaster.
The biggest obstacle to closing down the plant permanently is removing all the melted nuclear fuel debris from three reactors, Ono told reporters after a press tour of the plant this week.
But TEPCO says it is in the dark about the current state of the debris.
Hydrogen gas explosions and nuclear meltdowns released lethal levels of radiation in 2011.
Though radiation levels have fallen, they still prevent workers from accessing the reactor buildings, making it hard to survey the condition of the destroyed facilities and molten fuel debris.
What to do with the large volume of contaminated water now stored at the plant is another problem.
Around 300 to 400 tons of contaminated water is generated every day as groundwater flows into the plant filled with radioactive debris.
To contain the tainted water, TEPCO pumps up the water and stores it in tanks, adding a new tank every three to four days. There are 1,000 tanks today containing 750,000 tons of contaminated water.
However, decontamination elsewhere on the premises is making headway. Workers now only need dust masks for a large part of the plant.
For outsiders, this appears to be only small progress. But it makes a huge difference for workers who used to wear full masks for outside clean-up and construction work.
Last year in October, Japan confirmed the first case of cancer in a Fukushima worker.
While agreeing to cover the worker’s treatment costs, the government stopped short of recognizing the scientific link between the cancer and his work. “