TOKYO (AP) — 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 Unit 4 cooling pool is the first major step in a decommissioning process that is expected to last decades at the Fukushima Dai-ichi 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 Unit 4 can significantly reduce the risk at the plant."
The Unit 4 reactor was offline when the plant was hit by the disasters, but the building was damaged by hydrogen explosions and fire. Fuel rods in the pool, however, have since been properly cooled and are safe enough to remove, officials said.
TEPCO has reinforced the structure around the pool and says the Unit 4 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.
The Unit 4 cooling pool has attracted international attention in part because early in the crisis it was suspected to have dried up, when in fact there was enough water to cover the rods, keeping them from melting. TEPCO last year plucked two unused fuel rod units out of the pool and said no major corrosion or damage was found in them.