This is a particularly important update. An anonymous source in Japan has told reporters connected to the New York Times that there is a visible crack in the Fukushima Reactor 3. This is the reactor that showed isotopic evidence of a leak of some kind. Arguments had been made that a hole in the reactor vessel was an impossibility. The increasingly convincing evidence of a leak led people to admit, or realize, that the reactor vessel already has holes in it ... those designed to allow pipes and such in and out of the large thick-walled metal object. It was then presumed that this is where leakage was happening, and that remains a distinct possibility. This presumption was based on the repeatedly stated impossibility of the reactor vessel being burned or corroded through.
But now we have evidence of a visible crack. A crack is a whole nuther matter. If there truly is a crack and the crack is through-and-through and allowing leakage, the we may be observing an excellent and disturbing example of how nuclear accidents often play out, and, in fact, why they happen to begin with. There have been repeated arguments made, in the press, on this blog (in comments), and elsewhere that there is no way that even melted down nuclear stuff inside the reactor vessel could eat its way through that vessel. Then a concession was made for pipe-holes. In the end, however, eating through the vessel or corroded or melted pipes may not be the point. Cracking the vessel then leaking out may be a possibility. Hadn't been considered before.
There is isotopic evidence that the material leaking out of Reactor 3 is in part the product of fission that has occurred since shutdown of the machine at the time of the earthquake. This is not confirmed and there may be other explanations. But, if that is true, this probably means that fuel pellets have come free of their containment in fuel rods and accumulated somewhere in the reactor vessel in sufficient density to cause a chain reaction. If this has happened, it is probably not that severe of a chain reaction (or we would see more heat and other bad things). But, if there are fuel rods that have fallen apart, this means that future movement or pressure changes or other effects in the vessel could be more dangerous. Under some scenarios, just adding water can cause a brittle corroded fuel rod to fall apart, dropping more pellets into an accumulating pile of pellets lower down in the vessel.
Put metaphorically, the concentration of radioactive material in a mass that is increasingly close to that necessary to cause a chain reaction was dubbed, in the early days of nuclear research, "tickling the dragon's tail." Researchers, it is said, would move two piles of radioactive stuff closer and closer and measure the increase in radioactive output, in part to determine what a "critical mass" would be for that material. In theory, they would stop just before a high-level reaction occurred. Louis Slotin went to far with this technique in May, 1946 and it killed him.
If the isotopic evidence truly indicates that there has been post-quake fission in the reactor chamber, then this may mean that there is a dragon in there, metaphorically speaking We just have to hope that the Japanese engineers know how to keep the dragon calm.
There are other startling developments including a shakeup in the government. Ana has put together a very interesting feed. Read on:
Ana's Feed starting at about 7PM CT 25 March:
TEPCO says there must be a drastic review of work plans, due to very high radiation, before work can continue to restore electric cooling functions - the water in the turbine building of the No.1 reactor is at an almost equivalent level as that found in No.3. (NHK)
- Something about a plan to convert the steam produced in No. 1 into water for cooling??? Not sure how that would work... Meantime, fresh water will be pumped from trucks into No.1 and 3.
- Water is also observed in the turbine rooms at reactors 2 and 4.
Two of the three injured workers were not wearing high boots - were exposed to 2,000-6,000mSv while standing in water for two hours. (NHK)
- They are reported to have good appetite and there is not a high possibility for future development of leukemia. They will be monitored for skin changes over the next 3 weeks.
- "TEPCO plans to strictly enforce the rule of evacuating the site whenever dosimeter alarms sound after the radiation level tops 20 millisieverts.
Referring to the absence of a person who should have been in charge of radiation-level monitor..
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Japan Nuclear Plant Worker Recalls Narrow Escape
"I felt things shaking, and then it went crazy," Nishi recalled in an interview. "I was shouting, Stop! Stop!" Then the lights went out, leaving about 200 workers inside the reactor in near-darkness since the structure has no windows.
A small red emergency light started blinking. "Then some kind of white smoke or steam appeared and everyone started choking," Nishi said. "We all covered our mouths and ran for the door." But the door leading outside was locked, shut down automatically during the temblor to contain any leakage. The workers were stuck."
Pretty intense press conference with Yukio Edano - a shake up in the Prime Minister's cabinet, and some harsh Q and A re: TEPCO.
Mr. Mabuchi will replace Mr. Terata as assistant to the PM. The new man will deal directly with the nuke crisis - "as we try to respond, the strongest lineup...should be given the highest priority at this time." (Edano)
- Hand in hand with Mr. Hosono, under direction of PM Kan, Mabuchi will be in charge of disaster control, specifically with regard to Fukushima. He joined the task force early and has been very active, and since the scope of respose and task has expanded, Mr. Hosono wanted to step up the effort further. M. has a lot of experience - "I'm quite sure he's going to...provide a vital role." (Edano)
- Asked if this change indicates that the gov. hasn't been able to respond well up until now, Edano replies that the cabinet was not assembled with this disaster in mind. Given the unprecedented scale of the disaster, they needed to revise their personnel in order to respond better. (Seen on NHK)
- "Mabuchi was a member of Kan's Cabinet until mid-January. Along with then Chief Cabinet Secretary Yoshito Sengoku, Mabuchi came under pressure to leave the government after the opposition-controlled upper chamber passed a censure motion over his handling of the ship collisions last year involving a Chinese fishing boat near the Senkaku Islands, which are claimed by Beijing." -kyodo news
With reference to discovery that TEPCO had prior knowledge of the dangers the injured workers would encounter in the turbine building, a reporter asks "Did the government know the high radiation?" Edano: "We were not reported this information."
â
- (The NHK translator interjects - "Yes, he was asked this earlier too!")
- Q: TEPCO failed to give the report - and what do you think about this?
- Q: What do you have to say about this company?
- Edano: The workers are in a hard situation, we must be able to know the situation - without information it's difficult for the government to respond accurately and swiftly.
- Q: Do you think they were concealing facts?
- Edano: It is not our job to assess their position. We have to make sure that TEPCO does not act in ways that cause suspicion, "therefore we would like to give stronger instructions to TEPCO."
- Analiese Miller â(pieced and paraphrased from NHK broadcast)
- Q: "What is the outlook?"
- Edano: No definitive outlook that we can say at the moment, I do not want to make any comments that make people feel optimistic. We are taking measures so that the situation does not deteriorate any more - vigilance is required, even at this time. There are still a lot of preparations and operations to be done - a daunting amount of work that needs to be done. (NHK)
Lighting has been restored in the control room of reactor no.2. -kyodo news
Seismologists examining the quake found that the fault line moved 30 meters in 3 minutes. (NHK)
"The utility, known as TEPCO, said the radiation level at the No. 1 reactor of the plant has reached 200 microsieverts per hour, suspending work to pour seawater into its spent fuel pool. But its Fukushima office corrected the announcement later, saying no such high radiation level was detected." -kyodo news
Radioactive water in the turbine buildings of reactors no.2 and no.3 is over a meter and a half deep. (NHK)
- The decontamination equipment in reactor no.1 has been damaged in the quake - there are no ideas yet as to how to clear this water to permit workers to proceed with electrical. (NHK)
(Ana's Feed is a collection of Analiese Miller's facebook status entries posted as she takes in the news live in Japan.)
Links to news stories and updates:
- The situation at the quake- and tsunami-stricken Fukushima Daiichi nuclear powerplant in Japan was brought under control days ago
- 'Don't panic, protect N-energy facilities'
- Japan Extends Evacuation Zone Near Power Plant
- Marines help clear out Sendai Airport after tsunami
- U.S. forces to supply water to be pumped into Fukushima nuke plant
- Levels of radioactive materials soaring in sea near nuke plant
- Fault line shifted up to 30m
- Fukushima Crisis Could Have Long-Term Impact, Claims Chernoybl-Era Official
- Radiation in Fukushima reactor water could have been from core
- $1 million, 203-foot industrial fire truck en route to Fukushima plant
- Fukushima Update: It Could Be Worse
- U.S. Navy to Provide 500,000 Gallons of Fresh Water to Fukushima Power Plant
- Fukushima plant's fallout to go around globe
- Seawater near Japan plant tests high for radiation
- Govt may have avoided direct evacuation order to prevent panic
- Fukushima's MOX Fuel Reactor May Be Seriously Damaged
- Radioactive seawater in Japan raises new fears of reactor crack
For more information and essays about the Earthquake, Tsunami and Nuclear Reactor problems in Japan CLICK HERE.
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An anonymous source isn't evidence.
This sort of statement is just fear mongering:
"If there is a crack..we may be observing an excellent and disturbing example of how nuclear accidents often play out, and, in fact, why they happen to begin with."
Nuclear accidents don't happen "often". And the crack has nothing to do with why this incident began. The incident began due to an earthquake followed by a tsunami. This is the first example of this type of cause or playing out(Three Mile Island & Chernobyl had other causes and played out differently).
Makes for a tickling tale, though!
Once again, the ignorant panic from nuclear opponents is matched only by the overconfident "nothing bad will ever happen" rhetoric from nuke proponents.
I think a crack in any of the reactor vessels is unlikely and even if there was a crack might not be a serious problem.
The reactor vessels are low alloy carbon steel with an inner liner of stainless steel. Both would need to be perforated for the vessel to leak. The system is designed for an operating pressure of ~1040 psi at 550 F (287 C) (with a design pressure of 1250 psi at 575 F (302 C).
According to wikipedia, the reactor is well below 100 C, so the reactor can be at atmospheric pressure. Maybe it isn't to keep water in hot spots from boiling and to keep any gas volume small.
If there was a crack through the carbon steel outer vessel, it would rapidly corrode and because iron oxides have a higher volume than iron, any leak would tend to get smaller. There are going to be lots of particles in the water inside the reactor, from damaged fuel, from scale from the seawater being put in, from salt, from oxidized zirconium, from bits of fuel. These particles will tend to clog up the crack if they are small enough to enter it, sort of like radiator stop-leak.
What they need to do is get the radioactivity that has spilled out of the reactor vacuumed up and taken off site so the workers can get to where they need to be to do what they need to do. Once they get the liquid up, they can spread a couple of feet of sand on the floor to shield the workers from any residue on the floor.
In some ways because there is so much devastation around the plant, cleaning it up will be easier. They can just bulldoze a road to carry a gigantic concrete box to put radioactive crap into, take it off site and then bring the box back to put more crap in.
healthphysicist,do you know what that "URL" box is for?
"often play out" does not mean they happen often.
"This is the first example of this type of cause "
That is my fucking point.
"Makes for a tickling tale, though!"
You're going to have to do better than this.
WScott: Well, to be fair, I mostly picked examples that would show that, but yes.
daedalus2u: Hopefully it is not a crack, or at least, not a meaningful one.
âTickling the dragonâ referred to putting weapons grade fissile material together. There is a gigantic difference between that and reactor grade material.
There are 4 stages of being critical, there is sub-critical where any chain reaction dies out. There is critical where the chain reaction perpetuates itself indefinitely without increasing or decreasing There is supercritical where the chain reaction increases exponentially. There are two types of neutrons that are released, prompt neutrons which are released immediately (sub nanosecond) when the U235 fissions and then there are delayed neutrons that come out some time later, microseconds to minutes or longer. The only reason a fission reaction can be controlled is due to the delay in the release of some neutrons. That delay allows the control system to make the fissile assembly sub-critical before all of the neutrons from a particular fission event have occurred.
The most dangerous of all is hypercritical, where the chain reaction increases from prompt fast neutron release. In a hypercritical situation, a moderator is not necessary. Neutron reflection is not necessary.
When a fissile assembly is supercritical or hypercritical, the power produced by the assembly is increasing exponentially. What is different is the time constant for that exponent. When you are increasing the power in a reactor, you want that time constant to be long, at least seconds and when you are at high power even longer. You can do that with moderated neutrons because they move slowly and because some of the fission neutrons are delayed. That delay allows changes in the geometry to affect the reactivity and reduce the power. The BWRs in Japan were designed so that the voids produced by steam formation would reduce moderation of neutrons and reduce the reactivity. Higher power made more steam, made more void, made less moderation, made lower power.
In a hypercritical situation the time constant is very much shorter. The neutrons responsible for hypercritical fission are fast neutrons, MeV range, so they move very fast. You need a fairly dense fissile assembly for the fast neutrons to hit another fissile atom before they escape. The time constant in a hypercritical situation can be nanoseconds (as in nuclear weapons). That is the power of the assembly is doubling every nanosecond. That is why the assembly can produce so much power, it takes a few nanoseconds even for a 100,000,000 degree plasma to expand. With moderated neutrons, the neutrons are only moving a couple of km/sec, so the time constant is on the order of milliseconds.
You can get hypercritical situations following a reactor meltdown, but I think that is unlikely in Japan now because it is pretty old fuel with a relatively low fissile content. There is lots of crap mixed in with the fuel. It would likely go critical with moderated neutrons first (there is a much lower threshold for moderated neutrons because they are slower, and cause more fissions). In a water situation that would cause boiling and loss of moderation and the reactivity would go down, the assembly would go subcritical. Not something you want to have happen, but not the disaster of a hypercritical event. The event where too much high activity fuel was put into a tank and it went critical was a criticality event due to moderation, not a hypercritical event.
http://en.wikipedia.org/wiki/Tokaimura_nuclear_accident
0.1% boron would likely completely prevent any criticality event from happening. They are throwing so much boron at the reactor that I think it is likely that there is enough to prevent criticality.
âTickling the dragonâ referred to putting weapons grade fissile material together. There is a gigantic difference between that and reactor grade material.
It's a metaphor, so there is no technical definition.
But yes, thanks for the outline of levels of criticality. Important to keep in mind.
I get it...Greg's point is that the earthquake/tsunami is the first example of this sort of cause (and subsequent events) and at the same time illustrates how nuclear accidents often begin and play out.
I'm tickled!
To WScott - I never said nothing bad ever happens. I say the opposite...a lot of bad things happen all around us. But the routine bad things get ignored while we are distracted by the non-routine bad things, which aren't nearly as bad as the routine bad things.
Ok, tickling Carl Sagan's dragon. ;)
I'm tickled!
WScott - no one wrote that "nothing bad will ever happen".
Bad things happen all the time. In a proper context, what has happened in Japan is relatively minor to non-Japanese folks.
But it is tickling to read that this event is both unique and "an excellent and disturbing example of how nuclear accidents often play out, and, in fact, why they happen to begin with."
Why this event happened to begin with is unlike any other nuclear event of this scale. How it is playing out is unlike any other nuclear event of this scale.
Obviously the root cause of a problem of any engineered system can be ascribed to "bad engineering". Everything is badly engineered under certain conditions. That's why people die in car accidents. If cars were better engineered for their intended purpose, no one would die.
You may also be interested in how to treat radioactively contaminated drinking water:
http://crisismaven.wordpress.com/2011/03/22/dangers-properties-possible…
Maybe someone wants to help with Japanese and other languages?
daedalus2u: I suspect a lot of people will not get that joke!
Bad things happen all the time. In a proper context, what has happened in Japan is relatively minor to non-Japanese folks.
As a non-Japanese person I would prefer that you not make this generalization because it is racist and rude.
"Why this event happened to begin with is unlike any other nuclear event of this scale. How it is playing out is unlike any other nuclear event of this scale."
I understood what the OP meant, you did not. This accident is like every other one in two ways. First, it is unexpected and involves things that were not planned for. Second, as it plays out, nuclear power fanboys cheer-lead for the radiation and high cost of cleanup and health threats to workers.
Calling people from Japan, Japanese is not racist or rude. Japanese people live in Japan, just like Americans live in America. The race of most Japanese is Asian.
All accidents are unexpected and involve things not planned for (at these basically the same?). So every nuclear accident is like every car accident is like every stub your toe accident.
I have no idea what the second point is referring to. The people most hurt by this event are those in the industry. It is the industry workers taking the greatest dose. It is the Japanese nuclear investors taking the greatest financial damage. This event will cause at least a pause in global nuclear industry growth.
I am tickled.
Calling people from Japan, Japanese is not racist or rude. Japanese people live in Japan, just like Americans live in America.
Is your density purposeful? Must be. Your comment is offensive because you decided to write-off a major tragedy being experienced by a large number of people because they are not you, your kind, your country, your people. Also, not everyone affected was Japanese.
My comment was not racist nor rude. It was factually accurate. This incident has little impact on anyone not living in Japan. That doesn't de facto mean I am "writing it off" and I'm certainly not "writing it off" because the people are not me, my kind, my country or my people.
It is tragic for inhabitants of Japan (usually called "Japanese"), just like 9/11 was tragic for inhabitants of New York (usually called "New Yorkers"). But 9/11 had minimal impact on non-New York inhabitants.
My remarks on 9/11 are not made because I am not a New Yorker nor because New York is a different state nor because New Yorkers are not "my people".
My remarks on 9/11, like those of Japan, are factually accurate.
If you find facts offensive, then you have an issue you need to work on.
9/11 had significant impacts outside of New York. A plane crashed in a field in Pennsylvania, everybody on board died. The last time I was at the Pentagon I was not in New York. Homeland security and all its associated hoops for us to jump through happen everywhere, and there are analogs globally. Perhaps you don't travel and don't know about that. The Concord program ended that day as the Concord was half way from Europe at the time of the attack. That is not even a US company.
I suspect you have some reason for isolating global events into geographically distinct locals.
I do not find facts offensive. I do find you offensive.
Millions of dollars and thousands of lives were lost in New York. There are chronic effects effecting thousands of more lives of rescuers. This destruction far outweighs the costs in terms of lives and dollars from one plane crashing in PA. Hence, my statement was accurate. I never said 100% of the impact was born by NY'ers, but that the impact on non-New Yorkers (relative to NY'ers) was minimal. That is a fact....in terms of number of lives or dollars.
We are talking about an event, not what people do following it. The death and destruction due to 2 invasions following 9/11 are a much greater tragedy than 9/11. And these invasions (and 9/11 itself) are a much greater tragedy than the Japanese nuclear event. But the invasions were actions undertaken as a result of 9/11, they were not directly caused by the terrorists on 9/11. If people respond stupidly to this Japanese nuclear event, it will be because they respond stupidly. That is not a direct consequence of the earthquake or tsunami.
My larger point being that the cost of this Japan event, in terms of lives lost and dollars spent, will MOSTLY be incurred in Japan. That is not a racist or rude statement as you (erroneously and offensively) said. It is reality. If you find that reality offensive, or my documenting it offensive, then you have a problem with reality.
Americans should be more concerned about what causes lives lost and dollars spent in America (or if you're not American, whatever country you're in). For example, the food industry causes approximately 325,000 hospitalizations and 5,000 deaths in the U.S. EVERY YEAR! Let me repeat....EVERY YEAR!
http://www.cdc.gov/ncidod/eid/vol5no5/mead.htm
So using your "logic", I guess you are a rude racist for glossing over these American deaths. Why do you promote attention to a few Japaneses deaths over thousands of American deaths EVERY YEAR? Why do you hate Americans? (I can play too)
We can also look at the data for the auto industry, the medical industry, the gun industry, the coal industry, etc.
But that would be taking on reality again.
And you would find that offensive.
What would account for the white smoke/steam reported to be choking workers stuck in reactor no.3 immediately after the quake, I wonder?
Idunno :\
There are chronic effects effecting thousands of more lives of rescuers
effecting?
the impact on non-New Yorkers (relative to NY'ers) was minimal.
Between the airplanes (people not flying form or to NY) and those on the ground in the Pentagon, 371 people died in that event. You think of that as minimal. You are something of a monster.
How offensive!!!!
I should have typed "affecting"!
I must be a rude racist discriminating against the letter "a" in favor of the letter "e".
Sheme on me.
healthphysicist, you are a piece of work. Is there some point you are trying to make?
HealthP, when a disaster happens like this it involves all of us. That tsunami in Japan happened in my community and yours, because at this level of disaster the whole world is one community.