(Reuters) - Conditions at a stricken nuclear power plant in Japan have deteriorated so much that there is a growing consensus the crisis is greater than the Three Mile Island accident in 1979, and there are fears that it could get significantly worse.
Academics and nuclear experts agree the problems at the Fukushima Daiichi reactors are grave, and the solutions being proposed are last-ditch efforts to stem what could well be remembered as one of the world's worst industrial disasters.
All six reactors at the complex have problems -- be it blown-out roofs, potentially cracked containment structures, exposed fuel rods or just the risk of explosion that has been great enough to force emergency measures.
Of particular concern are a fire in a massive pool holding spent atomic fuel rods and a blast at the building housing the pool and reactor No.4. The pool is exposed to the elements, unlike the reactor core protected in steel and concrete.
"I would say that it has now eclipsed the Three Mile Island accident but it is not a Chernobyl," said Keith Holbert, director of the Nuclear Power Generation Program at Arizona State University and an associate professor there.
The accident at the Three Mile Island nuclear plant in Pennsylvania in 1979 was the biggest in U.S. history. Half of the reactor core in one unit melted due to the loss of coolant, though it resulted in no immediate injuries.
The Chernobyl accident in Ukraine in 1986 was the worst in the industry's history, as an explosion led to a cloud of radioactive material being spewed over big parts of Europe.
Several experts said that Japanese authorities were underplaying the severity of the incident, particular on a scale called INES used to rank nuclear incidents. The Japanese have so far rated the accident a four on a one-to-seven scale against Three Mile at a five and Chernobyl at a seven.
But that rating was issued on Saturday, and since then the situation has worsened dramatically.
In the past few hours alone, the plant's operator Tokyo Electric Power Co, said that a fire broke out at the building housing the No.4 reactor -- the same reactor that houses the troubled spent fuel pool.
Kyodo News reported, citing TEPCO, that the fuel rods in the No. 1 reactor were 70 percent damaged and the rods in the No. 2 reactor were 33 percent damage. Meanwhile, just after 10 a.m. local time Wednesday, Japanese TV reported white smoke coming from the plant.
"White smoke - meaning the steam release - would not necessarily be a good thing," ASU's Holbert said.
Separately, Japan's nuclear safety agency said two workers are missing and disclosed that there is a crack in the roof of the same building after an earlier explosion.
The International Atomic Energy Agency also said that TEPCO has been considering the removal of panels from the No.5 and No.6 reactors to prevent any hydrogen build-up. Such a build-up has led to explosions at several other reactors in the complex in recent days.
"This is a slow-moving nightmare," said Dr Thomas Neff, a research affiliate at the Center for International Studies, which is part of the Massachusetts Institute of Technology. "This could be a five or a six -- it's premature to say since this event is not over yet."
MORE HERE:http://www.reuters.com/article/2011/03/16/us-japan-quake-nuclear-us-idUSTRE72F08720110316
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