Shattered Unit 4 as it appeared on March 24th, 9 days after its "mysterious" explosionIn the earliest days of the Fukushima Daiichi nuclear catastrophe, the prevailing storyline on the explosion which destroyed the Unit 4 secondary containment reactor building was that the high-level radioactive waste storage pool had boiled dry, its wastes had caught fire, explosive hydgrogen gas was generated, which then blew up the building. But as posted at Beyond Nuclear's website, at the end of May, a U.S. Dept. of Energy spokesman revealed that the actual culprit may have been the Unit 3 reactor meltdown. The Mainichi Daily News now reports that Tokyo Electric Power Company is asserting just that, that hydrogen gas from the Unit 3 meltdown(s), rather than being vented out the stack shared with Unit 4, flowed instead into the Unit 4 secondary containment reactor building, blowing it up.
The likes of the Nuclear Energy Institute, the U.S. Nuclear Regulatory Commission, and President Obama's and Energy Secretary Chu's Blue Ribbon Commission on America's Nuclear Future will likely spin such news into a message of "pools are safe." This is not true. Fukushima Daiichi's pools storing high-level radioactive waste at Units 1, 2, 3, and 4 have had to be repeatedly re-filled with water, through various ad hoc, desperate, and dangerous means (such as failed helicopter water drops, as well as fire trucks, riot control water cannons, concrete pump trucks, etc. firing water from a radiologically safe(r) distance), due to the cooling water continually boiling away for lack of operable circulation systems.