Tokyo Electric Power Co. (9501) successfully removed the first nuclear fuel rods today from a cooling pool at the wrecked Fukushima nuclear plant, an early milestone in decommissioning the facility amid doubts about whether the rods had been damaged and posed a radiation risk.
The first of the fuel-rod assemblies at the plant’s No. 4 reactor building was transferred from an underwater rack on the fifth floor to a portable cask just before 4 p.m., the utility known as Tepco said in an e-mailed statement.
Tepco planned to remove 22 assemblies from the pool, which contains 1,331 spent fuel assemblies and 202 unused assemblies, by the end of tomorrow, the company said. Crews are beginning with the unused assemblies because they are less fragile, spokesman Yusuke Kunikage said by phone.
The operation is the most significant test to date of Tepco’s ability to contain the threat stemming from the worst nuclear disaster since Chernobyl. Were the rods to break or overheat, it could prompt a self-sustained nuclear chain reaction similar to the meltdowns at three Fukushima reactors following the March 2011 earthquake and tsunami.
“Although moving spent fuel into long-term storage is a routine task that Tepco has taken more than 1,200 times over the years, the circumstances at Fukushima Dai-Ichi require special care,” Tepco president Naomi Hirose said in a video message on the company’s website. “The success of the extraction process therefore represents the beginning of a new and important chapter in our work.”
Japan’s Nuclear Regulation Authority assigned an inspector to oversee the removals, in addition to its existing staff at the plant, and is using video monitoring of the removal, the agency said in a statement Friday.
An uncontrolled nuclear reaction due to structural failures or mishandled fuel is highly unlikely because of safeguards and workers’ experience with the procedure, Akira Ono, the Dai-Ichi plant’s chief supervisor, said at a Nov. 7 news conference at the power station.
Removing the rods, bunched in assemblies, will take place from a large shoebox-shaped structure cantilevered atop the reactor building, which was damaged in an explosion after the earthquake and tsunami. The assemblies, each holding about 80 rods, will be moved to a more secure pool on the ground.
Tepco said that it plans to complete the removal of all the fuel in the pool by the end of 2014.
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