Canadian Manufacturing

Japan nuke cleanup hobbled by radioactive water

The work threatens to exhaust the supply of workers for other tasks, as they must stop working when they reach annual radiation exposure limits



OKUMA, Japan—More than three years into Japan’s massive cleanup of a tsunami-damaged nuclear plant, only a tiny fraction of the workers are focused on the key tasks of dismantling the broken reactors and removing radioactive fuel rods.

Instead, nearly all the workers are devoted to a single, enormously distracting problem: coping with the vast amount of water that becomes contaminated after it is pumped into the reactors to keep the melted radioactive fuel inside from overheating.

The numbers tell the story:

6,000 workers – Every day, some 6,000 workers pass through the guarded gate of the Fukushima Dai-ichi plant located on the Pacific coast, two to three times more than when it was actually producing electricity.

But only about 100 of them are dismantling a makeshift roof over one of the reactor buildings, while about a dozen others are removing fuel rods from a cooling pool.

Most of the rest are dealing with contaminated water-related work, said Tatsuhiro Yamagishi, a spokesman for TEPCO, as the utility that owns the Fukushima plant is commonly known.

The work threatens to exhaust the supply of workers for other tasks, since they must stop working when they reach annual radiation exposure limits.

40 years – The plant has six reactors, three of which were offline when disaster struck on March 11, 2011—a 9.0 magnitude earthquake that triggered a huge tsunami, which swept into the plant and knocked out its cooling systems, leading to meltdowns at the three active reactors.

Decommissioning and dismantling all six of the reactors is a delicate, time-consuming process that includes removing the melted fuel from a highly radioactive environment as well as all the extra fuel rods, some of which sit in cooling pools situated at the top of the reactor buildings. The entire job is expected to take at least 40 years.

500,000 tons – Workers have jury-rigged a pipe-and-hose system to continuously pump water into the reactors to cool the clumps of melted fuel inside.

The water becomes contaminated upon exposure to the radioactive fuel, and much of it pours into the reactor basements and maintenance trenches that extend to the Pacific Ocean.

The plant recycles some of the contaminated water as cooling water after partially treating it, but groundwater is also flowing into the damaged reactor buildings and mixing with contaminated water, creating a huge excess that needs to be pumped out.

So far, more than 500,000 tons of radioactive water has been stored in nearly 1,000 large tanks that workers have built, which now cover most of the sprawling plant site. After a series of leaks from the storage tanks last year, they are now being replaced with costlier welded tanks.

That dwarfs the 9,000 tons of contaminated water produced during the 1979 partial meltdown of Three Mile Island in the United States. At Three Mile Island, it took 14 years for the water to evaporate, said Lake Barrett, a retired U.S. nuclear regulatory official who was part of the early mitigation team there and has visited the Fukushima plant.

“This is a much more complex, much more difficult water management problem,” said Lake Barrett, a retired U.S. nuclear regulatory official who was part of the early mitigation team there and has visited the Fukushima plant.

10 trillion yen – An estimated 2 trillion yen (US$18 billion) will be needed just for decontamination and other mitigation of the water problem. Altogether, the entire decommissioning process, including compensation for area residents, reportedly will cost about 10 trillion yen, or about $90 billion.

All this for a plant that will never produce a kilowatt of energy again.

About 500 workers are digging deep holes in preparation to build a taxpayer-funded 32 billion yen ($290 million) underground “frozen wall” around the four reactors and their turbine buildings to try to keep the contaminated water from seeping out.

TEPCO is developing systems to try to remove some of the radioactive elements from the water. One, known as ALPS, has been trouble-plagued, but utility officials hope to achieve their daily capacity of 2,000 tons when they enter full operation next month.

Officials hope to be able to treat all contaminated water by the end of March, but that is far from certain.

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