“The plant is in a difficult physical configuration. I have some sympathy,” said Klein, a former chairman of the US Nuclear Regulatory Commission.
“It’s not the fact that we’re having surprises — it’s the way they’re handling them. That’s where my frustrations are,” Klein said.
TEPCO says it is dealing with the clean-up hand-in-hand with the government. It has also relied on expertise from the US Department of Energy and General Electric.
A Reuters investigation in December found that foreign companies had won few, if any, contracts to develop technologies for scrapping the reactors.
TEPCO, accused by experts of lacking transparency even before the disaster, was heavily criticized in the days after the calamity for not providing timely information to the public.
It was more than two months before it said three of the six reactors at the plant had suffered nuclear meltdowns. Industry experts had suspected meltdowns long before that.
Since the beginning of this year, the plant has been plagued by problems.
A worker on the site spotted steam rising from the No. 3 reactor building, but TEPCO has only been able to speculate on its cause. In March, a rat shorted a temporary switchboard and, for 29 hours, cut power used to cool spent uranium fuel rods.
Experts say TEPCO is attempting the most ambitious nuclear clean-up in history, even greater than the Chernobyl disaster in 1986.
One of its biggest headaches is trying to contain radioactive water that has cooled the reactors after it mixes with the 400 tonnes of fresh groundwater pouring into the plant daily.
Workers have built more than 1,000 tanks to store the mixed water, which accumulates at the rate of an Olympic swimming pool each week.
With more than 85 percent of the 380,000 tonnes of storage capacity filled, TEPCO has said it could run out of space.
The tanks are built from parts of old, disassembled containers brought from defunct factories and put together with new parts, workers said. They say steel bolts in the tanks will corrode in a few years.
TEPCO says it does not know how long the tanks will hold. It reckons it would need to more than double the current capacity over the next three years to contain all the water. It has no plans for after that.
Instead, the utility wants to stem the flow of groundwater before it reaches the reactors by channeling it around the plant and into the sea through a “bypass”.
The groundwater would be captured at the elevated end of the plant into a system of wells and channeled into pipes that would carry it to the sea.
Local fishermen oppose the idea, dismissing TEPCO’s claims that radiation levels in the water would be negligible.
Meanwhile, TEPCO’s improvised efforts to stop radioactive water leaking into the sea include sinking an 800m long steel barrier along the coastline, injecting the ground with solidifying chemicals and possibly even freezing the ground with technology used in subway-tunnel construction.
Industry experts are not impressed.
“You can’t do temporary fixes in nuclear power,” Goto said. “They say everything’s fine until bad data come out.”