I already posted links on the kind of reactor, how the reactor works and what a worst case scenario would look like … just read it … it’s pretty much what they explain in the magazine.
I’m not worried, I’m not panicking … yet.
So… they find high levels of radiation near a power plant in Miyagi Prefecture, north of Fukushima (not east!)… and a spokesperson for the company running the reactor (not the same company in charge of the Fukushima reactors) suggests that the radioactivity must have come from Fukushima. So, we now know that at least one of two power companies is feeding us BS.
BBC:
Wikipedia:
(Haven’t found the Japanese original yet, sorry…)
The wind has been blowing, and is blowing, from a westerly direction. The Fukushima explosion was reported as having been most likely a Hydrogen explosion that did not damage the container housing the reactor - that type of explosion is plausible under the circumstances, and if the explanation is true, it would not have led to much fallout.
Let’s believe what we are told. Oops - WHICH of those two explanations should we believe?
Thinking about how chaotic the situation is in Japan, and how unprepared they were for the explosion and cooling system failure, I wouldn’t be surprised if there are a lot of unknowns in regards to what actually has come out of the Fukushima reactor and where it went. If radiation has made its way to Onagawa, where the environment is being monitored, radiation may have traveled to other areas, too, but hasn’t been detected yet.
How did radiation get out of the Fukushima reactor in the first place? Is the core still leaking?
Just a nitpick, but that doesn’t mean anything in a small local area. It could well be going north because of the contours of the land, influenced by sea and mountains. I go out biking most days in Taipei and I get hit by wind in every direction.
[quote=“archylgp”]Thinking about how chaotic the situation is in Japan, and how unprepared they were for the explosion and cooling system failure, I wouldn’t be surprised if there are a lot of unknowns in regards to what actually has come out of the Fukushima reactor and where it went. If radiation has made its way to Onagawa, where the environment is being monitored, radiation may have traveled to other areas, too, but hasn’t been detected yet.
How did radiation first get out of the Fukushima reactor in the first place? Is the core still leaking?[/quote]
What they’ve said is, the coolant problem led to a buildup of (to some degree radioactive) hydrogen gas in the reactor chamber. This was vented into the reactor building (according to plan) but a system designed to vent it from there into the atmosphere failed, leading to a buildup and explosion.
This is some good news for now:
So radiation was released during the explosion…It seems the sea-water method isn’t going as planned:
world-nuclear-news.org/RS_Ve … 03111.html
Here are two other decent articles (they don’t say anything new, though)
Fukushima crisis: Anatomy of a meltdown blogs.nature.com/news/thegreatbe … _of_a.html
blogs.nature.com/news/thegreatbe … risis.html
The tension mounts: economist.com/blogs/asiaview … earthquake
Just a nitpick, but that doesn’t mean anything in a small local area. It could well be going north because of the contours of the land, influenced by sea and mountains. I go out biking most days in Taipei and I get hit by wind in every direction.[/quote]
You may be right, and i won’t argue about things i don’t know: the wind may well have been coming from the southwest instead straight from the west when the explosion happened, and so stuff could have drifted from the exploding building to the other power plant.
These are the things you can confirm for yourself: the Onagawa plant lies on a peninsula northeast of Sendai City while the Fukushima reactors are about 100km south of Sendai. Radioactivity near the Onagawa plant has been reported as being 700 times the normal level - and the Onagawa plant has been reported as having (had) a fire after the quake. If the cause of the increased radiation level near that plant is, indeed, the explosion of the reactor housing situated over 100km to the south-southwest, then we should expect significant levels of radioactivity also in between the two plants, in all of the destroyed towns along the coast, including Sendai, and especially near the Fukushima plant. There are people out there checking for radiation, but i haven’t seen any reports to that effect (not that it proves anything, i admit - but with all the military personnel and other rescue crews working in that area and reporters moving about, i would think someone would have reported about such radiation by now).
Whichever way you look at it, somebody must be lying (even if by way of omitting or supressing information). Either the Onagawa person is trying to deflect attention from the problems at the Onagawa plant or the Fukushima people are not telling us about highly elevated radiation levels downwind from their plant as far as north of Sendai and beyond.
[quote=“archylgp”]So radiation was released during the explosion…It seems the sea-water method isn’t going as planned:
world-nuclear-news.org/RS_Ve … 03111.html[/quote]
That website looks like a pretty interesting read. Concise info on the facts out there, apparently from experts (although pro nuclear power by definition). Thanks!
More bad news.
[quote=“BBC”]A second explosion has hit the nuclear plant in Japan that was damaged in Friday’s earthquake, but officials said it had resisted the blast.
TV footage showed smoke rising from Fukushima plant’s reactor 3, two days after an explosion hit reactor 1.[/quote]
According to the info available so far it seems to me your opinion is not correct 
As far as I understand: The venting was indeed steam directly from the water surrounding the fuel rods. Normally this steam is indeed radioactive when vented, but only so for very short times (seconds). Due to suspected damage by overheating to the fuel rods’ case, there seems to be some radioactive Cesium and Iodine mixed with the steam, which is where the measured radiation in the areas around there probably is from.
The thing I am worrying about is: What happens if the core indeed melts, gathering enough uranium (away from control rods or the boric acid in the water) to get critical, starting a chain reaction again? Well, we will see…
Some links to websites with more info - I guess the truth is somewhere in between the “OMFG media mentioned meltdown we are all going to die just like Chernobyl” and “Even if all 5 reactors blow up I am cool since nothing will happen”. Some seem to be pro-nuclear, but nonetheless seem to give a good idea about some of the basics and about what is currently happening:
en.wikipedia.org/wiki/Fukushima_ … r_accident
blogs.nature.com/news/thegreatbeyond/
world-nuclear-news.org/
bit.ly/joehmen
nytimes.com/2011/03/14/world … actor.html
The New York Times says there’s been damage to one containment building, and the roof has been blown off another, yet both are said to be intact. Please advise.
[quote=“The New York Times”]So far, Japanese officials have said the melting of the nuclear cores in the two plants is assumed to be “partial”. . . . [/quote] nytimes.com/2011/03/14/world … actor.html
So is it that a partial meltdown is not a meltdown, or is the New York Times (or the quoted Japanese officials) perhaps mistaken as to whether there was a partial meltdown? Again, please advise.
According to the info available so far it seems to me your opinion is not correct
As far as I understand: The venting was indeed steam directly from the water surrounding the fuel rods. Normally this steam is indeed radioactive when vented, but only so for very short times (seconds). Due to suspected damage by overheating to the fuel rods’ case, there seems to be some radioactive Cesium and Iodine mixed with the steam, which is where the measured radiation in the areas around there probably is from.
The thing I am worrying about is: What happens if the core indeed melts, gathering enough uranium (away from control rods or the boric acid in the water) to get critical, starting a chain reaction again? Well, we will see…
Some links to websites with more info - I guess the truth is somewhere in between the “OMFG media mentioned meltdown we are all going to die just like Chernobyl” and "Even if all 5 reactors blow up I am cool since nothing will happen". Some seem to be pro-nuclear, but nonetheless seem to give a good idea about some of the basics and about what is currently happening:
en.wikipedia.org/wiki/Fukushima_ … r_accident
blogs.nature.com/news/thegreatbeyond/
world-nuclear-news.org/
bit.ly/joehmen[/quote]
Almost missed the wink.
I’m definitely not cool if all 5 reactors blow. But from everything I’ve read is that chances of a meltdown are low at this point and the containment structures are intact (perhaps the 1st containment of 3 is slightly breeched in 1 or 2 cases). This is why I’m not really concerned about this right now and haven’t been.
Charlie I’m not certain but it’s possible that containment building and the building built around the containment building have been used interchangeably. From the other articles that I’ve read I don’t think the explosions occurred inside containment but rather outside the building which might not be anything than a steel framed building with sheet metal (think of an aircraft hanger). Containment walls are at least a meter thick of reinforced concrete and I believe that pressure would have been vented well before that level of explosion happened.
Thanks for the explanation. I just looked at a New York Times piece from the 12th that said about as much:
[quote]They said that the blast, which may have been caused by a sharp buildup of hydrogen when the reactor’s cooling system failed, destroyed the concrete structure surrounding the reactor but did not collapse the critical steel container inside. This pattern of damage cast doubt on the idea that the explosion was in the turbine building.
“We’ve confirmed that the reactor container was not damaged,” Mr. Edano said in a news conference on Saturday night. “The explosion didn’t occur inside the reactor container. As such there was no large amount of radiation leakage outside. At this point, there has been no major change to the level of radiation leakage outside, so we’d like everyone to respond calmly.”[/quote]
nytimes.com/2011/03/13/world … ted=2&_r=1
As to the term meltdown, this is from a New York Times piece on the 13th:
[quote]The difference between a partial meltdown and a full meltdown at a nuclear plant is enormous, both in the degree of damage and in the potential release of radiation, experts in nuclear power said.[/quote] nytimes.com/2011/03/14/scien … ss&emc=rss
In one of the New York Times articles (or I think it was the New York Times), I read that they’re putting boron in the seawater to try to decrease the level/intensity/amount/rate/whatever-the-proper-term-is of nuclear reaction. And I think the article said that one U.S. nuclear expert called it (either the seawater, the boron, or both, I forget) a “Hail Mary pass.”
And now it’s three. [quote=“Toronto Star”]The second hydrogen explosion in three days rocked a Japanese nuclear plant Monday, devastating the structure housing one reactor and injuring 11 workers. Water levels dropped precipitously at another reactor, completely exposing the fuel rods and raising the threat of a meltdown.
The morning explosion in Unit 3 of the Fukushima Dai-ichi plant was felt 25 miles (40 kilometres) away, but the plant’s operator said radiation levels at the reactor remained within legal limits. Hours later, officials reported that fuel rods at Unit 2 were fully exposed at some point and may have been damaged.[/quote] Still not worried?
Per the BBC website just now:
1431: More from Japanese nuclear engineer Masashi Goto: He say that as the reactor uses mox (mixed oxide) fuel, the melting point is lower than that of conventional fuel. Should a meltdown and an explosion occur, he says, plutonium could be spread over an area up to twice as far as estimated for a conventional nuclear fuel explosion. The next 24 hours are critical, he says.
1426: Mr Goto says his greatest fear is that blasts at number 3 and number 1 reactors may have damaged the steel casing of the containment vessel designed to stop radioactive material escaping into the atmosphere. More to follow.
Well, I hope it works out that way, because it seems to me the challenges they have right now are plenty.
Abacus, you state facts but no links. Nothing supporting what you are saying. Can you cite something in the effect that the plants are now on their way to a safe shutdown?
[quote]The morning explosion in Unit 3 of the Fukushima Dai-ichi plant was felt 25 miles (40 kilometres) away[/quote]25 MILES AWAY??? Do you have any idea how large an explosion has to be to be felt that far away? It doesn’t sound like a safe shutdown to me at all!
Unless the reactor vessel is compromised, there will be nothing more than low level radiation relesased to the surrounding environment. This is because the reactor core is the only place these significant quantities of radiactive elements exist. If it is only vented steam exiting the reactor, the small mass of actual containments just won’t be high enough to pose a lagitement risk. This is not necessarily applicable for those working at the plant, where radiation levels are likely at dangerously high levels.
And, if the reactor vessel is compromised, there would have to be an explosion in the core similar to that of Chernobyl where the contents of the core were strewn for hundreds of meters, allowing for winds to carry the contaminents for many many miles.
What is alarming is that the core has not cooled down to a controllable level yet and that hydrogen is still being produced, an indicator that the reactor is still fissioning and hence uncontrolled (‘melting down’ if you will). Nuclear reactors are not as easy to understand as Wikipedia might lead you to believe, but looking at massive hydrogen explosions blowing the roofs oof of reactor buildings is not exactly an inconsequential event. The steel frame that has been blown off on the tall white/blue concrete block looking building is the roof of the tertiary containment vessel, i.e., the reactor building. This leaves the concrete/steel secondary containment and the steel reaction vessel. the ‘cap’ of the vessel and the spent nuclear fuel pool (the old fuel that has been removed from the vessel) both live under this roof, so there is a lot of bad to worry about here. both the reactor fuel and the stored spent fuel must remain under water at all times to avoid an uncontrolled reaction.
The workers and operators staying and working at these sites are incredibly brave and should be treated as hero’s at this point.
photo of a very similar US plant with the reactor cover removed for refueling. After the reactor is shut down it takes about 2 days for the radiation and heat to lower enough to remove the cover. Notice a worker is safe to be where they are due to the ‘shielding’ from the water.
what you see here is at the top: the concrete secondary cover removed (concrete is a a few feet thick). then about 35 feet of water down to the reactor vessel ‘head’ (which has also been removed) and then another 20 feet or so down to the ‘blue’ shinning fuel (the core). water is what keeps the radiation at bay.
notice the metal roof frame in the background
This photo is of the same plant except the reactor cover is not removed (upper left side of the photo). As you can see, next to the reactor is the spent fuel pool, litterally right next to the reactor. The fuel, when it is removed, is simply shifted over to this pool and stored for the entire life of the reactor. some of the fuel you see in this photo has been there since 1970. It also needs to remain underwater at all times or will ‘melt down’ as well. You are looking at about 30 - 40 feet of water down to the spent fuel assemblies.
What the previous photos have shown is the top floor of a reactor building. Covering all of this is simply a metal roof (sometimes concrete on the dome top reactor designs). Again all of these photos are of the same reactor (a single reactor site). The short green building (middle right) is the turbine housing.
Now knowing what the top of a nuclear reactor building has in it and roughly what it looks like, what does this look loike to you?
notive the shorter and elongated turbine buildings in the background.
before/after
It should be noted that these power plants are a Japanese design, but the reactor vessel itself is GE, some as those used in US plant designs.
German media reports that measured radioactivity is rising and the wind will blow from North to South today which could result in a very real threat for people in Tokyo.
pretty scary stuff if you ask me.