Despite the Japanese PM’s optimistic assessment of Fukushima, experts have new worries about the plant’s recovery.
But Mr Noda’s optimistic assessment appears to have been premature. Nuclear engineer and former power company executive Arnie Gunderson compared the prime minister’s statement to President George Bush declaring “mission accomplished” on the deck of the USS Lincoln in 2003. Gunderson calls the situation at Fukushima “a long battle, far from over.”
But nuclear experts say that their biggest concern involves Reactor 4, which sustained severe structural damage during the earthquake and subsequent hydrogen explosions which collapsed its roof. This is where hundreds of tons of spent fuel sits perched 100 feet above the ground in a cooling pool exposed to the open sky.
A report released in February by the Independent Investigation Commission on the nuclear accident called this pool “the weakest link” at Fukushima. Robert Alvarez, former senior policy adviser at the US department of energy said: “If an earthquake or other event were to cause this pool to drain it could result in a catastrophic radiological fire involving nearly 10 times the amount of Cs-137 released by the Chernobyl accident.”
How likely is this? While the structure of Reactor 4 is stable for the moment, the Dai-ichi plant lies miles from a big earthquake fault – as large as the one that caused last year’s quake, but much closer to Fukushima. According to a study published in February (pdf) in the European Geosciences Union’s journal Solid Earth, that fault is now overdue for a quake.
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