Fukushima nuclear plant faces prolonged battle against radioactive debris, water

By Shunsuke Kimura, Jin Nishikawa, Eisuke Sasaki, and Hidenori Tsuboya
7 June 2011 As workers struggle to bring the Fukushima No. 1 nuclear power plant under control, signs are increasing that the eventual cleanup of the disaster will take much longer than previously thought. Containers of rubble, unwanted and of unknown levels of contamination, line the roadside near the plant. Pools of radioactive water at the plant, a constant problem since the March 11 disaster, may pose even longer-term challenges. And full studies on how to remove nuclear fuel and eventually decommission the four troubled reactors have yet to start. Tokyo Electric Power Co., the plant’s operator, started using remote-controlled, unmanned heavy machinery in late April to put radioactive debris into containers each with a capacity of about 4 cubic meters. By June 5, 279 containers had been filled. “We don’t know where we can take the containers,” said a TEPCO spokesman. In fact, the spokesman said the company has no idea about the aggregate volume of the debris nor the amount of radiation for each container. … Another huge challenge is how to dispose of nuclear fuel that remains in the reactors and the storage pools. The No. 1 to 3 reactors contained 1,496 fuel assemblies, or clusters of fuel rods, while the storage pools for the No. 1 to 4 reactors held 3,108 fuel assemblies. An estimated five to 10 years are needed to remove the nuclear fuel from the reactors after they reach a stable cold shutdown state. … But a paper carried in the online edition of Britain’s Nature magazine soon after Toshiba’s announcement said decommissioning work would take decades, even 100 years. The paper quoted “veterans of cleanup operations” as saying that many more years will be needed at Fukushima than the 11 years required to remove fuel after the accident at the Three Mile Island nuclear power plant. It also pointed out that following a fire in 1957 at a nuclear facility in Sellafield, Britain, the reactor remained as it was for 20 years. …

TEPCO faces prolonged battle against radioactive debris, water