It had been a while since we had a factual update (as opposed to just lies and spin) from Fukushima. Courtesy of Kyodo, we now know that what was speculated by some as true, and rebutted by most as mere scaremongering, is in fact, fact. “Some of the spent nuclear fuel rods stored in the No. 4 reactor building of the crisis-hit Fukushima Daiichi power plant were confirmed to be damaged, but most of them are believed to be in sound condition, plant operator Tokyo Electric Power Co. said Wednesday.”
Naturally, in one month we will learn that most of them are damaged, and in two months, that each and every one has been demolished. “The firm known as TEPCO said its analysis of a 400-milliliter water sample taken Tuesday from the No. 4 unit’s spent nuclear fuel pool revealed the damage to some fuel rods in such a pool for the first time, as it detected higher-than-usual levels of radioactive iodine-131, cesium-134 and cesium-137.”
These confirm an ongoing fission reaction. In a tremendously ironic development, the No. 4 reactor, halted for a regular inspection before last month’s earthquake and tsunami disaster, had all of its 1,331 spent fuel rods and 204 unused fuel rods stored in the pool for the maintenance work. Unfortunately, the entire pool ended up being damaged following the quake and the subsequent explosion, in essence nullifying any protection that the containment dome would have provided.
As the picture from the Asahi Shimbun below shows, the damage from overhanging structures which have subsequently fallen into the fuel pool likely means that there could well be an uncontrolled, if weak, fission reaction currently going on in the reactor 4 SFP (where the water temperature is currently 90 degrees) unprotected by the elements due to the complete destruction of the Reactor 4 shell.