Roof completed for removal of spent fuel rods at Fukushima plant
February 21, 2018 As reported by HIROSHI ISHIZUKA in the Asahi Shimbun.
The article focuses on Tokyo Electric's plans to begin removing 566 irradiated nuclear fuel assemblies from the Unit 3 "wet" storage pool at Fukushima Daiichi. Those operations could begin this autumn.
The roof is intended to keep radioactivity contained during these operations, so it doesn't escape into the environment.
Some years back, during dismantling operations at Unit 3, large-scale hazardous radioactivity fallout in the form of dust was stirred up, to blow downwind and fallout on rice paddies. It was yet another nuclear disaster, in an ongoing nuclear catastrophe. And it was due to Tokyo Electric's incompetence and carelessness.
Unit 4's "wet" storage pool had come precariously close to boiling dry in March and April 2011. The only reason it did not was through sheer luck, it was later reported. A gate separating the "wet" storage pool and the adjacent reactor cavity was damaged on its edges by either the earthquake or the explosion that damaged Unit 4. The edges of the gate allowed water, which was fortuitously located in the reactor cavity, to flow into the "wet" storage pool. If this had not happened, the pool could have boiled down to the tips of the irradiated nuclear fuel assemblies by about a month into the nuclear catastrophe, as reported by the likes of the U.S. Natioinal Academy of Science.
The Japanese Prime Minister serving in 2011, Naoto Kan, later publicly revealed that he had had a secret contingency plan in the works. Had the Unit 4 pool boiled dry, and its irradiated nuclear fuel caught fire, he would have evacuated 35 to 50 million people from metro Tokyo and northeastern Japan, to escape the fallout. The fallout, especially of Cesium-134 and Cesium-137, would have been an order of magnitude worse than the reactor releases from three meltdowns! This according to the likes of Bob Alvarez of Institute for Policy Studies.
Unit 4's irradiated nuclear fuel was transferred out of its "wet" storage pool as a top priority post-catastrophe. The entire Unit 4 reactor building, including the "wet" storage pool, was on the brink of collapse, due to the damage from the hydrogen explosion that wrecked it.
Unit 3's reactor building was also rubblized by the biggest explosion of all that fateful week. The explosion left the pool filled with large chunks of debris that had rained down. It also left the pool uncovered, facing the open sky.