Nikkei.com is reporting that damage to the fuel rods at the #1 reactor at Fukushima I is 70%, not the 43% previously reported, and 33% of #2’s fuel rods have been damaged. Meanwhile, #5 and #6 are overheating, but they are claimed to be under control — even though #5 has lost is coolant system.
Over at my Facebook page, on hearing that news about #5 and #6, a friend asked the question, “How many do they have, anyway!?”
The answer is six, at Fukushima I, but there are four more at Fukushima II.
Of those ten reactors, eight have failed to operate as planned, though only 3 (actually? probably? possibly? maybe?) experienced core meltdown.
At Fukushima I, only #4 reactor, which was shut down before the earthquake, isn’t having a problem with the cooling of its reactor as such. And that one is where the spent fuel rods caught fire and explosions blew not one but two 8-meter holes in the building. So…it’s not entirely accurate to say that 9 out of 10 of the Fukushima plants had trouble. It’s 8 out of 10, plus a spent fuel pool.
Incidentally, I saw a BBC report that the #4 reactor fire might have been caused by machine oil, not hydrogen like the other explosions. Hydrogen is generated by steam reacting with the zirconium in the zircaloy (zirconium alloy) fuel cladding that holds the fuel rods.
Here’s the status, as I know it, gleaned strictly from the news.
Fukushima I (Fukushima Daichi):
Reactor #1 has had either 43% or 70% of its fuel rods damaged. That DOES NOT mean a 43% or 70% meltdown. A partial meltdown was confirmed in reactor #1, but it’s not clear how much melted down.
Reactor #2 has had 33% of its fuel rods damaged, but a meltdown hasn’t been confirmed. Reactor 2, however, did have a breach of the containment vessel confirmed, which is probably more significant than a meltdown.
Reactor #3 is where, just a few minutes ago, white smoke was seen rising. Nobody knows why. Earlier, Reactor #3 had a hydrogen explosion. The white smoke could be steam (in fact, it probably is), which would be expected. It could potentially be radioactive. It is not known if #3 suffered a partial meltdown or not.
Reactor #4 is the strangest animal. The reactor itself appears to be fine. It was shut down for maintenance at the time of the earthquake. The problems there come not from the reactor itself but from the cooling system on the spent fuel rods that are stored in what’s called a spent fuel pool at #4. The spent fuel rods are still very hot, both thermally hot and radioactive, and you have to keep water circulating over them in order to keep them cool. Don’t worry, though; former US Navy nuclear engineer, nuclear entrepreneur and pro-nuclear blogger has been the voice of reason throughout the crisis when it comes to the fuel rods. In an article in his blog Atomic Insights, he says he talked to his friends, who said that very little water is required to keep the spent fuel pool cooled off. Here’s what Adams wrote:
Apparently there are now “experts” who are trying to get people up in a tizzy about used fuel pools. I have exchanged private email with some friends who have operation experience at similar types of plants as those at Fukushima Daiichi. In their opinion, it is possible to keep used fuel pools cool enough by simply refilling them with water every once in a while. We talked about using fire hoses and one more numerically inclined contributor to the discussion said that a typical garden hose would provide a sufficient quantity of water in just a couple of hours each day.
…which is probably why there were not one but (apparently) two huge explosions at the #4 reactor, big enough to blow not one but two 8-meter holes, apparently, in a concrete structure. I say “apparently” because the NHK reports are sort of confusing — I’m not entirely clear if there were one or two explosions at #4. NHK released a photo of the damaged #4 structure, incidentally. Apparently these folks couldn’t find a garden hose.
The “experts” link that Adams objects to above goes into a sign-in-only article at the New York Times, so I have no idea who the hell is pissing him off. But surely, he wouldn’t have to cast his net very far to find an ill-informed media pundit spreading unscientific misinformation.
For instance, news agencies are reporting that the #4 spent fuel pools are the “main” problem now, which I see absolutely no indication of. I’m not sure where they got that; maybe they made it up. Or maybe it’s a red-herring created by the release of the photo of the damaged #4 structure. Who knows?
Incidentally, Rod Adams headlined that post of his reminding us that it is always wrong to panic, which is surely good advice. Panic never results in anything good happening.
But Adams reminded us at the outset of his post that this happened as a result of “an enormously powerful earthquake followed by a higher than expected tsunami.” “Higher than expected”? I’m the first one to admit I don’t know jack about uranium or plutonium metallurgy, cooling systems, or radiation. But I live in California. I know a small amount about earthquakes. “Higher than expected”? Does Adams know anything about tsunamis?
Anyway, get ready for some good news! It comes from reactors #5 and #6. Until very recently, there had been no problems at #5 and #6, which were shut down for a routine inspection before the earthquake. At last report, they were both overheating “slightly,” whatever that means. Then the c0olant system at #5 failed. Tepco said they can re-route the coolant system of #6 to cool down #5, too. since #6 seems to be the only reactor at Fukushima I with a working coolant system.
Sadly, we’re not quite done yet. There is a second Fukushima facility.
Fukushima II (Fukushima Daini):
Fukushima II, or Fukushima Daini (Fukushima I is Fukushima Daichi) is 11 kilometers away. Fukushima II has four reactors. Following the tsunami, three out of four of them were placed in emergency status. Those three had problems with their cooling systems and residents were evacuated. Those three had reached “cold shutdown,” in which the cores were at 100 degrees centigrade or lower, about 34 hours after the catastrophe, according to World Nuclear News:
The power plant’s four boiling water reactors stopped automatically on last week’s earthquake. At unit 3 the shutdown appears to have gone exactly as expected, with no systems damaged by the huge earthquake or tsunami. It went from power production to cold shutdown – where coolant water is at less than 100ºC – in about 34 hours.
All the reactors have remained safe, but damage to the emergency core cooling systems of units 1, 2 and 4 led to the announcement of emergency status. Those reactors used their a secondary system, the make up water condensate system, and this was used to maintain coolant levels above the reactor core. An additional emergency notice came from unit 1 concerning the temperature of a suppression chamber, which reached 100ºC after some time.
The plant then continued in a relatively steady state throughout 12 March, with coolant levels always maintained but a high level of attention from engineers. Units 1, 2 and 4 were prepared for potential pressure release, but this was never required.