TEPCO, nationalized and burdened with the astronomical cleanup costs, has been criticized for repeatedly lagging in attempts to tackle leakage problems. As a precautionary step, it has created chemical blockades in the ground along the coast to stop any possible leaks, but experts question their effectiveness. After a nearly two-year delay, construction of an offshore steel wall designed to contain contaminated water has begun.
The utility has also proposed building frozen walls — upside down comb-shaped sticks that refrigerate surrounding soil — into the ground around the reactor areas, but that still has to be tested and won’t be ready until 2015 if proved successful.
Prime Minister Shinzo Abe earlier this month announced that the government would intervene and provide funding for key projects to deal with the contaminated water problem.
“This is a race against the clock,” said Toyoshi Fuketa, a commissioner on Japan’s Nuclear Regulation Authority.
Compounding TEPCO’s problems is the new leak discovered this week. Most of the 300 tons is believed to have seeped into the ground, but some may have escaped into the sea through a rainwater gutter, said Zengo Aizawa, the company’s executive vice president.
That, too, may be a harbinger of more problems ahead.
Some 1,000 steel tanks built across the plant complex contain nearly 300,000 tons (300 million liters, 80 million gallons) of partially treated contaminated water. About 350 of the tanks have rubber seams intended to last for only five years. TEPCO spokesman Masayuki Ono said the company plans to build additional tanks with welded seams that are more watertight, but will have to rely on rubber seams in the meantime.
Shinji Kinjo, a regulatory official in charge of the Fukushima disaster, said the rubber-seam tanks were mostly built in a rush when the contaminated water problem started, and often lacked adequate quality tests and require close attention.