17 Octobre 2012
October 17, 2012
http://www.japantimes.co.jp/text/nn20121017a5.html
By JUN HONGO
Staff writer
Remote-controlled underwater cameras have located parts of a 35-ton fuel transfer apparatus that fell into reactor 3's spent fuel pool in March 2011 in the early days of the Fukushima No. 1 crisis, Tokyo Electric Power Co. said.
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Inconvenient debris: Broken heavy equipment lies in the spent fuel pool of reactor 3 at the Fukushima No. 1 nuclear power plant, as seen by a remote-controlled underwater camera. TEPCO / KYODO |
According to Tepco officials, an inspection of the storage pool last Thursday and Friday showed parts of the equipment that broke off following the hydrogen explosion that ripped through the building three days after the complex was overrun by tsunami from the Great East Japan Earthquake.
"We now know approximately where the equipment fell," an official at the utility told reporters Monday, adding the spent fuel rods in the pool apparently were not damaged by the impact.
The fractured fuel-handling machinery had been used for carrying fuel assemblies between the reactor and the spent fuel pool, which sits on the fourth floor of the reactor building.
Images released by Tepco showed a motorized device, concrete blocks and steel beams spread over the racks that contain the spent fuel rods. The hydrogen explosion that took place in reactor 3 is believed to have been larger than the blasts that occurred at reactors 1 and 4.
According to Tepco, the temperature of reactor 3's spent fuel pool remains stable at about 20 degrees. But the area around the reactor still has high levels of radiation 18 months after the disaster started, and the removal of debris surrounding the pool, carried out with remote-control machines, has been time-consuming.
Last month Tepco divulged the complexity of the cleanup process when it said a steel beam weighing 470 kg had fallen into the reactor 3 pool while an operator was trying to remove it.
The pool contains 566 spent fuel assemblies. Tepco has said it hopes to take away enough debris inside and begin removal of the fuel rods within fiscal 2014.