The operator of Japan's crippled Fukushima nuclear plant is preparing to remove 400 tons of highly radioactive spent fuel from a damaged reactor building, a dangerous operation that has never been attempted on this scale. If it goes wrong, the consequences could be far worse than the plant's nuclear accident in March 2011.
More than 1,300 spent fuel rod assemblies packed tightly together need to be removed from a building that is vulnerable to collapse should another large earthquake hit the area. The assemblies contain radiation equivalent to 14,000 times the amount released in the atomic bomb attack on Hiroshima 68 years ago.
The accident happened when a powerful offshore earthquake sent a tsunami sweeping across Japan in March 2011, killing more than 15,000 and causing an explosion at the plant that sent radiation spewing from a damaged reactor. Cleanup is forecast to take 40 years and cost $11 billion.
"They are going to have difficulty in removing a significant number of the rods," said Arnie Gundersen, a veteran U.S. nuclear engineer and director of Fairewinds Energy Education, a nonprofit group that provides educational material on nuclear power and safety.
The operation, beginning this November at the plant's Reactor No. 4, is fraught with danger, including the possibility of a large release of radiation if a fuel assembly breaks, gets stuck or gets too close to an adjacent bundle, Gundersen and other nuclear experts said.
Extracting spent fuel is a normal part of operations at a nuclear plant, but safely plucking the rods from a badly damaged reactor is unprecedented. Tokyo Electric Power Co (Tepco), operator of the facility, already is trying to stop radioactive water overflowing from another part of the plant. It only recently admitted that there was such a leak.
"Full release from the Unit-4 spent fuel pool … could cause by far the most serious radiological disaster to date," independent consultants Mycle Schneider and Antony Froggatt said recently in their World Nuclear Industry Status Report 2013. The most serious release of nuclear radiation from a reactor accident to date occurred at the Chernobyl plant in Ukraine in 1986.
The company removed two unused fuel assemblies from the pool in a test operation last year, but those rods are less dangerous than the spent bundles, and experts question whether it will be able to pull off the removal of the assemblies safely.
"To jump to the conclusion that it is going to work just fine for the rest of them is quite a leap of logic," Gundersen said.
The utility says it recognizes the operation will be difficult but believes it can carry it out safely.
Tepco has been sharply criticized for failing to protect the Fukushima plant against natural disasters and for its handling of the crisis since the quake. Last week, Prime Minister Shinzo Abe ordered the government to take a more active role in controlling the overflow of radioactive water being flushed over the melted reactors in Units 1, 2 and 3 at the plant.
If another strong earthquake strikes before the fuel is removed, a spent fuel fire releasing more radiation than during the initial disaster is possible. Tokyo, a city of 13 million, is 125 miles from the plant.
When asked what the worst scenario was that Tepco is planning for, spokesman Yoshikazu Nagai told Reuters: "We are now considering risks and countermeasures."
Al Jazeera and Reuters