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Wednesday, 30 October 2013

Regulators OKs fuel rod removal from pool at Fukushima plant

Regulators OKs fuel rod removal from pool at Fukushima plant The steel structure for the use of the spent fuel removal from the cooling pool is seen at the No. 4 reactor of the Fukushima Daiichi nuclear plant .AP Photo/Noboru Hashimto, Pool
Japanese regulators on Wednesday formally approved the removal of fuel rods from an uncontained cooling pool at a damaged reactor building considered the highest risk at a crippled nuclear plant.
Removing the fuel rods from the No. 4 reactor cooling pool is the first major step in a decommissioning process that is expected to last decades at the Fukushima Daiichi plant, where three reactors melted down after the March 2011 earthquake and tsunami.
The Nuclear Regulation Authority said at its weekly meeting that the proposal by the plant’s operator, Tokyo Electric Power Co, is appropriate and that the removal can start in November as planned, following an on-site inspection by regulators. Japanese public broadcaster NHK said the removal would start as early as Nov 8, but TEPCO said it may not announce the date in advance, citing security reasons.
“It’s a major step toward decommissioning,” said Toyoshi Fuketa, one of the authority’s five commissioners. “Moving the fuel rods out of No. 4 can significantly reduce the risk at the plant.”...s reinforced the structure around the pool and says the building can survive a major earthquake, but the unenclosed pool on the unit’s top floor, which contains 1,533 fuel rods, has caused international concern. About 200 of the rods that are unused and safer are expected to be the first to be removed...
...“It’s a totally different operation than removing normal fuel rods from a spent fuel pool,” Tanaka said at a regular news conference. “They need to be handled extremely carefully and closely monitored. You should never rush or force them out, or they may break.”
He said it would be a disaster if fuel rods are pulled forcibly and are damaged or break open when dropped from the pool, located about 30 meters above ground, releasing highly radioactive material. “I’m much more worried about this than contaminated water,” Tanaka said.
TEPCO has prepared a massive steel structure that comes with a remote-controlled crane to remove the fuel rods, which will be placed into a protective cask and transferred to a joint cooling pool inside a nearby building. To make room for the fuel rods, the company has been moving those already in the joint pool to safer storage in dry casks at a separate plant location.
The utility plans to empty the pool by end of 2014, and remove fuel rods from other pools at three other wrecked reactors over several years before digging into their melted cores around 2020.
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