Ever since Japan was hit by an earthquake and a tsunami in 2011, the Fukushima Daiichi nuclear power plant has leaked 300 tons of radioactive water per day. In an effort to protect local water, the Japanese government announced a plan Tuesday to spend 32 billion yen (approximately US$320 million) on an underground "ice wall" to prevent contaminated water from flowing out to sea. In addition to the ice wall is a 15 billion yen project to upgrade water treatment plants in the area to remove radioactive elements, placing the mission's total budget at 47 billion yen, just shy of half a billion dollars.
Bill Horak, chair of nuclear science and technology at Brookhaven National Laboratory in New York, said that it's not just the storage containers that are a source of water contamination. "There's an aquifer underneath the plant that runs out to the sea, like an underground river," he told ABC News. "It picks up contaminants that have leaked into the ground, and no one has a good handle on how contaminated that water is."
The so-called ice wall may conjure up images of igloos, but Horak said that it's not so much an actual wall of ice as it is a network of coils, similar to what you would find in the refrigerator or freezer. "The coils transport liquid nitrogen at 30 degrees Kelvin, which freezes the ground and builds an impenetrable wall," he said.
Prime Minister Shinzo Abe said the government needs to intervene in order to properly address the handling of Fukushima. "Instead of leaving this up to [Tokyo Electric Power Company], the government will step forward and take charge," he said in a statement. "The world is watching if we can properly handle the contaminated water."
Tokyo is currently one of three cities still in the running to host the 2020 summer Olympics, along with Madrid and Istanbul. Tokyo is projected to get the bid from the International Olympic Committee, but addressing these kinds of problems may be what tips the scales in the Japanese city's favor. Naoki Inose, the chairman behind Tokyo's 2020 bid for the Olympic Games, said that the situation in Fukushima will not affect Tokyo.
Horak isn't sure whether Japan's ambitious project is the right direction to head in. "When we had a leak at Brookhaven about 13 or 14 years ago, we put a bunch of stripper wells to pump the water before it got off site," he said. The lab kept the water in a closed loop and played the waiting game for the radioactive element tritium (an isotope of hydrogen) to decay naturally. Tritium has a half life of 12.3 years. "I don't know if anyone has actually tried this frozen wall concept for this type of activity."
But there is still uncertainty as to what radioactive elements are actually being leaked in the water. "Most of the radioactive nuclei have been cesium and iodine," said Horak. "But if you have actinides, the nastier and heavier elements like uranium and plutonium, that would be a whole other thing entirely."
- Nature & Environment