Tweet
Reactor Containment & Fuel Storage from UCS; (h/t commenter lobster)
It’s 10:00 pm EDT here; it’s 11:00 a.m. Tuesday in Japan.
Sandbags. That’s right, we’re literally down to sandbags to keep a trench filled with highly radiative water from spilling its content into the sea. From NHK World (and see video of drawings here):
On Monday, the power company detected radiation of more than 1,000 millisieverts per hour on the surface of puddles in the No. 2 reactor’s turbine building and in a trench outside the building.
The concrete trench stretches toward the coast but does not connect to the sea.
Puddles of water were also found in the trenches of the No.1 and No.3 reactors.
The No.1 reactor’s trench will overflow if the water rises by 10 centimeters. TEPCO has blocked the trench outlet with sandbags and concrete to prevent the water from reaching the ocean.
The water in the trenches of the No.2 and No.3 reactors is reportedly 1 meter from overflowing.
To provide context, recall from our last update that TEPCO was trying to figure out how to remove contaminated water from two to five feet deep in the lower rooms of each of the turbine buildings. There is a turbine/generator building next to the reactor building at each Unit of the Fukushima Daiichi Nuclear Station.
Apparently, the water is leaking from somewhere, still unknown, along the chain of pipes and valves coming from the reactor into the turbine building and eventually returning to the reactor. In the turbine building the pressurized steam enters and turns the turbine/generators. The expanded, now cooler steam then passes through a condenser where it becomes water. Then it’s further filtered for mineral buildup and then piped/pumped back into the reactor building and returned to the reactor.
So an initial plan was to pump the contaminated water into the condenser tanks, putting it back into the closed loop leading back to the reactor. But apparently the condensers for Units 2 and 3 are already full.
The authorities still don’t know where the water leaks are occurring along that chain. But given the levels and types of radiation, that water is presumable picking up radiation from the damaged fuel rods in the reactor, suggesting fuel rod disintegration and fuel deterioration inside (what the media are calling “melting”). Japanese officials have essentially admitted there is some degree of core damage or “melting” in Unit 2.
There may also be contaminated water in the large pressure suppression pool beneath the reactor core. They suspect this structured was damaged in the explosion more than a week ago in Unit 2.
[Update, Tuesday a.m. EDT: the "trenches" appear to be several meters deep and filled with water (h/t powwow). Recall that these lower levels nearer the ocean were flooded by the tsunami, so most of the water could be left over from that, with only part of it contributed by leaks from inside the turbine building. Since the first reports, I haven't seen updates that indicate the levels are rising, and if so, how fast. So for the moment, its yet another large pool of contaminated water they have to monitor closely and work around.]
In addition to not knowing the source/location of the water leaks within the turbine building, they can only guess at the rate at which water is leaking. That means that as they continue to inject water into the reactor to keep the core from overheating, they have to guess at how much water/pressure they can “safely” inject without exacerbating the leaks that are flooding parts of the turbine building next door. And now, it seems the leaked water accumulating inside the turbine building is following gravity on its way to the ocean, via a tunnel that leads from the turbine building towards the sea.
And each of those tunnels is close to overflow, so they’re literally piling sandbags and concrete to erect a barrier to hold it in until they can figure out how and where to pump it out.
They can’t get close enough to find the leaks, but they have to keep injecting water. The more they inject, the more they have to worry about it overflowing and eventually spilling into the ocean. Inject too little, risk further “melting” in the reactor; inject too much, risk further ruptures and worse leaks and an overflow into the sea.
And in the meantime, there’s now a clear pathway for high radiation levels from the damaged reactor to the open environment.
Nightmare.
In slightly better news, they’ve found traces of plutonium in soil samples near the plants that, they claim, are not much elevated from normal levels. Here’s a Q&A from Kyodo News on what this may mean. Detailed readings here (h/t Selise).
Helpful Sources:
NYT: Contaminated water escaping nuclear plant, Japanese officials say
Kyodo News: Japan Nuclear Crisis
Nuclear Power Plant Primer — good expert video
Unit by Unit status updates (pdf) at the IAEA site
NYT Radiation chart
Washington Post simple graphics
TEPCO press releases
fleep.com/earthquake
NHK press releases
The Breakthrough Institute (including the Twitter feeds)
195 Comments
i really appreciate your daily posts on this — recommended and tweeted with thanks.
sandbags! ohmystars
Thanks for the update SC.
How this one ends in anything but a worst case disaster is beyond me. The complexity involved with it all as a multi disaster event is mind boggling.
Defenders of the Earth, Physicians for Social Responsibility and Nuclear Information and Regulatory Service have jointly filed a freedom of information request to the U.S. Department of Energy and the U.S. Nuclear Regulatory Commission for them to release the info they’ve been collecting on radioactivity levels and to explain why they evacuated Americans up to a 50 mile radius from Fukushima.
http://www.salem-news.com/articles/march252011/japan-nuclear-reactors.php
An excerpt from the above article:
”
As the FOIA request explains, the three groups “seek expedited release” of the requested information, “so that they may timely inform their members and the general public about the unfolding events at the Fukushima reactors, including the significance of the public health and environmental threat posed by radiation releases from the Fukushima reactors. Requesters believe that requested disclosures will do a great deal to fill currently existing information gaps and resolve inconsistencies in the currently available reports about the severity of the Japanese radiological releases.”
The groups also contend that expedited release of the information is justified in order to allow them to participate in and comment on any proceedings the federal government may undertake to evaluate the lessons learned from the Fukushima accident, including the 90-day review of the safety of U.S. reactors recently announced by the NRC. According to the FOIA request letter, a better understanding of the severity of the Fukushima releases is “essential to Requesters’ ability to evaluate and participate in any such review.”
”
Here’s some further helpful detail from Tokyo resident “Millie Sievert” (who’s getting much more comprehensive, precise information from the coverage by the Japanese media than English speakers are), from comments made earlier today (aka the anniversary of the Three Mile Island accident…) at the end of the thread to Scarecrow’s preceding post:
Something that’s occurred to me, and I hope to the people on the ground if it’s feasible, is the possibility of using the nearby empty reactor pressure vessel of Unit 4 to hold/store the leaked water found in the turbine buildings and trenches of Units 1-4, provided that a) they can find a way to pump that water via the ‘feedwater’ or ‘fire extinguish’ lines into Unit 4′s reactor core (those lines are being used to pump cooling water into the other three cores from outside their buildings), and b) the volume of leaked water would all or mostly fit into the steel reactor core vessel (I have no clear idea of either the volume of water a reactor core can hold, emptied of fuel rods, or the volume of highly-radioactive water that now exists outside the reactor buildings – although “14.9 meters” seems pretty deep…).
— I can hear the ghost of Rube Goldberg laughing – from my house in Wasilla, even.
I would also like to see the release of radiation levels measured in the US. The reports of safe and insignificant levels tells us nothing.
Scientific analysis from Seattle shows that the first week’s worth of radioactive particles reaching the US were from steam, not from fuel rods.
Thanks PJ, but they don’t give any numbers to compare with acceptable dose limits. Also the elements they list are from the core they are the lighter ones carried by the steam.
Here’s my guess: it’s leaking at the rate they are injecting. All that water is going somewhere, now we know where.
Even if the reactor vessels are intact, even if the concrete containments are intact, the plumbing, joints, and valves have undergone: 9.0 earthquake, tsunami, multiple hydrogen explosions, heat and pressure spikes, buildings falling on them. Oh, and some of it is approaching 40 years old.
Do any of the executives have swimming pools at their luxury homes? That seems like a good place to store radioactive waste water.
what is the source of “normal levels” of plutonium? do they know if it is plutonium-244 or plutonium-239?
if plutonium-239 is it residual from ww2? some other source of contamination?
i’d think that there wouldn’t be some uniform background level (unless widely dispersed from prior weapons testing). wouldn’t it be more like to be concentrated near previous contamination source(s).
are they comparing current readings at site to local readings prior to earthquake?
i have no knowledge on which to be doing this speculating — can someone fill me in on how to interpret the quoted statement (just in case it’s true)?
Since they or we don’t know the source of the radiation that’s speculation. Any info on what radionuclides are in the water?
Which officials? TEPCO? Cause TEPCO officials or whoever is working there are the only sources of info like that.
They don’t even tell you the amount they detected. They mention a paper in the scientific archive called aarXiv.org but they don’t provide a link to the paper.
They don’t even tell you the amount they detected. They mention a paper in the scientific archive called arXiv.org but they don’t provide a link to the paper.
powwow@7:59
Great catch.
This document details TEPCo’s plutonium measurements, and includes a brief analysis of the results as compared to background levels, selise (actually, a third party did the measuring and analysis, I believe, under contract to TEPCo), for the five soil samples:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110328e14.pdf
Kyodo News has also published this Q&A for their general, non-scientific audience re the detected plutonium:
http://english.kyodonews.jp/news/2011/03/81702.html
Here’s a link to the original the Seattle arxiv paper mentioned above by PJEvans et al . I posted it in comments several days ago but maybe worth repeating.
Latest update from Fuji TV
Lights on in central control room of #4. The lights in the control rooms of all 6 reactors are now on.
Fresh water (not seawater) is now being pumped into the cooling pool of #3. (Earlier an announcer had said #3 was full. I do not know if it is full or not, but the pumping truck being used is able to pinpoint where the water goes, so my assumption is that the water level of #3 is not a problem at the moment.)
They are currently planning to put the contaminated water into the turbine storage tanks. First they need to empty the storage tanks of the water that is currently in them. They are rigging pumps to pump water from the storage tanks into the “suppression surge pool” (which is apparently a giant pool on the premises, several hundred meters away).
That 10 cm of freeboard before the radioactive spillage runs away uncontrolled and into the sea is 4 inches. Your extended palm from wrist to fingertip is 6-8 inches.
Little wonder then that the Japanese government is considering nationalizing TEPCO – bailing it out faster than it can the pool of radioactive water.
I don’t doubt that’s a good idea. Properly executed clean-up and recovery efforts would likely drive even Japan’s largest utility into a strategic bankruptcy, with TEP dropping whatever liability Japan’s laws and sometimes rigid customs would permit. That would force the government to step in anyway and finish the job to its chosen standard. It would also reverberate around the global nuclear industry, and the global utility and general Japanese stocks for months.
I am concerned, though, about whether it would decrease already opaque transparency about what happened, why and what its real effects have been and are likely to be, and what lessons learned we should all take from this, which are dependent on knowing what really happened.
I know nothing about radiation so forgive my ignorance, but I think my questions are the kind that folks in my area would ask. Of course, they aren’t being asked or answered…we are all just trusting the government, because really there is no other choice. Repeatedly folks here have reassured that radiation will be detected nationally and will likely stay within a safe range and be no problem for health and wellness. This is the part I don’t fully understand. Increased radiation was detected at our nuclear energy plant because they monitor it. They know it’s not coming from our plant and that it is from Japan. They say that the isotopes found have a short half life…which is good. They tell us that they pose no risk.
Here’s my question. How can we know for sure, that isotopes with longer half lives will not “build up” over time as Japan is still leaking radiation into the “world”? How can we know that we can trust the government to be telling us the truth about all this? What if the radiation that went into the atmosphere was much more than they told us? It seems like details regarding half life and things like that are important for us to know and could be info that is easily manipulated.
Do we know for sure that this increase in radiation will not be a hazard in the U.S or globally when the leak has not been stopped?
The source for the idea that Japan might nationalize TEPCO, owing to “mounting criticism of its handling of the worst [peacetime] nuclear disaster in country’s history.”
Ominously, there could be several sources of leaks – at the same time. Sources cite possible breaches in the RPV, the turbine-to-reactor system, the pressure release “donut” below the RPV, etc.
I wonder how much, if any, is owing to degradation of piping/pumps due to chloride contamination from seawater.
powwow @10:42 – Looking at that data, I think the Pu came from the core as opposed to the spent fuel rods. I’d expect to see more Pu-238 and PU-240 in the spend fuel rods.
Per CNN, Japan is now admitting there may have been a partial melt at 3 reactors, as opposed to two. Dunno if this is news or not, I was kinda disconnected from FDL over the weekend.
Boxturtle (*insert daily gripe about miserable interleaving comments here*)
You do not have to trust the government on these questions, wavpeac. It is not difficult to measure radioactivity. There are hundreds to thousands of private citizens around the country doing this and no one is reporting dangerous levels. I will try to put together a post describing these efforts — it will probably be the weekend. In the meantime, if you are antsy, contact the physics department of the closest college or university and ask them whether they can measure radiation in the environment/atmosphere. They should say yes and they probably already have such monitoring (informal, i.e., not official, but of high technical quality) underway.
It is not possible to hide the radiation. That is actually the problem, but in this case, it also means that no government can hide from accountability.
The cited Guardian article talks about TEPCO being in tense negotiations with lenders for emergency loans. Under the current circumstances, no responsible lender – or even America’s TBTF banks – would loan large amounts to TEPCO without a government guarantee. The risk of non- or partial repayment is too obvious and too great. A smart bank or supplier would consider reducing its credit exposure to TEPCO, which has lost 70% of its stock value in the past two weeks, a slide that isn’t likely to reverse itself for quite some time.
If the Japanese government is going to guarantee repayment of one to several billion dollars worth of loans to TEPCO – Asia largest power utility – it would be smart to nationalize it first. If it’s going to be on the hook to save the company, it will be on the hook practically to see that it identifies and makes necessary changes to TEPCO’s management and processes.
If it’s going to do that, it ought to give itself the power to oversee the investigation of who and what needs changing, and the power to make those changes promptly. The Japanese people – and those with commercial and community relations with TEPCO – will hold the government to account anyway. The government might as well buy up what it needs to obtain that control while the stock price is down.
That’s a logic that Mr. Bush and Mr. Obama adamantly rejected when bailing out banks, but not big auto. That cash in but hands off policy allowed the banks to “fix” themselves, with hundreds of billions of taxpayer cash. Unsurprisingly, banksters fixed nothing but their own bonuses. Fortunately, the US model makes less and less sense to the rest of the world.
Hanford nuclear site: outstanding article Seattle Post Intelligencer:
http://seattletimes.nwsource.com/html/localnews/2014001657_hanford23m.html
whole thing should be in quotation marks. (immediately prior post)
Per English translations of the news conference, that conclusion came from Edano, the Goverment Minister who has been dealing with the media since the first week. In the translations, they’ve used the word “melting”.
There is a suppression surge pool at the bottom of each reactor. It’s the doughnut shaped tank you see in the diagram above, top of the post. In that diagram, it’s labeled the “wetwell” or “torus.”
As I understand it, this doughnut-shaped pool functions like an emerency heat sink. If the pressure inside the reactor vessel gets too high because of loss of cooling/steam build up, then they can release steam/pressure directly into the supression pool, while reinjecting cooler water at the top of the reactor. The suppression pool is still inside the containment structure, as is the reactor vessel, so this is presumably less risky than releasing potentially radioactive steam into the rest of the building or atmosphere.
The problem with that though is simple geiger counters can’t tell you what is emitting that radiation.
does radiation build up over time? And do geiger counters tell you the type of isotope?
thanks powwow! from your link: Result of Pu measurement in the soil in Fukushima Daiichi Nuclear Power Plant
Units are: Bq/kg・dry soil
1．Result of the measurement
Pu-238
① site field 13:30, March 21st — (5.4±0.62)×10-1
②１km away from Unit 1/2 exhaust stack 7:00, March 22nd — N.D.
③ 0.75km away from Unit 1/2 exhaust stack 7:10, March 22nd — N.D.
④ 0.5km away from Unit 1/2 exhaust stack 7:18, March 22nd — N.D.
⑤ solid waste storage 7:45, March 22nd — (1.8±0.33)×10-1
ordinary domestic soil (MEXT environmental radiation database; 1978-2008) — N.D.～1.5×10-1
Pu-239,Pu-240
① site field 13:30, March 21st — (2.7±0.42)×10-1
②１km away from Unit 1/2 exhaust stack 7:00, March 22nd — (2.6±0.58)×10-1
③ 0.75km away from Unit 1/2 exhaust stack 7:10, March 22nd — 1.2±0.12
④ 0.5km away from Unit 1/2 exhaust stack 7:18, March 22nd — 1.2±0.11
⑤ solid waste storage 7:45, March 22nd — (1.9±0.34)×10-1
ordinary domestic soil (MEXT environmental radiation database; 1978-2008) — N.D.～4.5
２．Analysis
Density of detected Pu-238, Pu-239 and Pu-240 are within the same level of the fallout observed in Japan after the atmospheric nuclear test in the past. Activity ratio of Pu-238 detected in site field and solid waste storage against Pu-239 and Pu-240 are 2.0 and 0.94 respectively. They exceed activity ratio of 0.026 which resulted from the atmospheric nuclear test in the past, thus those Pus are considered to come from the recent incident
And to make it even more interesting:
1) Not all of the waste there is cataloged. We’ll be finding buried drums forever.
2) Even if they clean the tanks up, there are no plans to deal with what has already leaked other than to let it migrate to the river. Enjoy your salmon while you can.
3) Ignoring the radiation for a moment, chemically speaking they have NO idea what they’re dealing with. Even the tanks they’ve opened to analyize have mixtures never before created. You have to assume the contents are explosive, corrosive, carcinogenic, mutagenic, poisonous AND radioactive.
4) The entire place is fouled with Beryllium. That won’t show on the radiation detectors.
The heck of it is, vitrification WILL work to contain the tank contents. The trick is safely handling the process.
Boxturtle (And when we’re done there, there’s someone from Rocky Flats on line 2)
To elaborate a bit on lobster’s 4:03, any physics department with significant nuclear/particle lab research will have gamma spectrometers, which certainly will tell you what’s emitting the radiation. In fact, many undergraduate lab courses have the relevant instrumentation. It’s important to remember that measurable and significant are different words! Spectrometers detect single photons at a time. It takes quadrillions of photons to be of biological consequence.
To fml’s point, in a health sense it hardly matters where it’s coming from, though it’s always good to know. For the simple question of “is the level dangerous” a geiger counter is probably good enough.
I work on a lab floor (in MA) full of radiation monitors which are on all day every day. Their scales are to detect health consequences for humans. None of the background readings have moved an iota due to any of the events in Japan. I expect none of them ever will.
earlofhuntingdon: I saw that report about potential leak sources, but find it confusing. The question was, how does the water get into the turbine building?
It may be true that the reactor vessel has a leak, or the suppression donut, etc, but those are inside the reactor building. That doesn’t explain how that water would get to the bottom of the turbine building.
So my assumption has been, if leaking is the cause of the puddles in the turbine building, that must be caused by leaks inside the turbine building — i.e from the pipes, valves, tanks, etc inside that building.
newspeak?
atmospheric nuclear test in the past = ww2 bombing of 2 japanese cities by usa.
Prof Foland. Yeah, I suspect there are thousands of places all over the country that routinely monitor radiation levels and would know immediately if the levels went up — and they are no doubt checking closely out of curiosity.
Question: what’s the policy at your place, and your understanding of policies at similar places, about whether they would tell the media/us when they saw an unusual reading?
I put it in quotes. Lemme know if they’re not in the right place, and we’ll fix.
Selise and powwow — I’ve added a link from selise’ comment wrt plutonium readings. Thanks
I don’t know how much higher these readings are above backround levels, but these are the readings taken by the DPHS in Concord, N.H. from snow samples.
http://www.seacoastonline.com/articles/20110328-NEWS-110329793
This isn’t the torus, this is a different pool. The suppression surge pool (this is how it was labeled in Japanese) is a large pool, only one, as I said, located several hundred meters away from from the reactors.
My continuing appreciation to all, Scarecrow, lobster, Prof. Foland, EOH, powwow, selise, and others who understand far more than I.
Your daily perspectives are invaluable, especially when gummint “information” is essentially worthless, designed primarily, it would seem, to protect the “interests” of a powerful few, despite the fact that every single person on this planet, who is not among the “protected” has a basic and fundamentalo “interest” in the truth.
DW
It’s more than that. All the nuclear weapons tested all over the world deposited some radioactive elements all over the world in small quantities but still detectable.
They count the number of times the detector is hit by a particle.
http://en.wikipedia.org/wiki/Geiger_counter
They can’t tell you if it’s coming from cesium, iodine, plutonium, etc.
Some of you might find this site interesting. Graphing of radiation readings at various places throughout Japan during the past few weeks. In English..
http://fleep.com/earthquake/
No one is in denial about core melt-down or compromised fuel in the reactors. With all the hydrogen blowup, the Cabinet Secretary said more than a week ago that fuel has melted. (Whether it has melted through any steel is a separate issue, and not able to be confirmed) So it would follow that bits would escape with water if injection is going on into the reactors and water seems to be escaping and not just turning to steam.
Sand bags match fire hoses as the right sort of tools, we still have not seen angle grinders so I guess we’re OK.
The worry about these trenches is that apparently they are not structures that are made entirely waterproof. They were not designed or intended to hold water. It is also a surprise that there is no drain at the bottom, or so it would appear. How someone would design a rain, tsunami, burst pipe catching structure without drainage is strange. It is in this case lucky that the water is not escaping. Earlier press conference consisted mostly of discussion of where to store and how to transfer the water. So it would appear there is some storage capacity left.
“does radiation build up over time? And do geiger counters tell you the type of isotope?”
Do you mean does it multiply all by itself? Then no it doesn’t.
It’s not the radiation you are probably thinking of but the elements that are emitting the radiation. If there’s a source leaking radioactive elements then yes they would accumulate as long as that source is leaking radioactive elements.
Very good data, but take heed of the warning at the top of their page: “Please note that the graphs do have different scales depending on the data. All Radiation readings are converted to μSv/h for consistency.” The y axis is completely different for Fukushima and shows far greater readings than most other areas.
thanks.
and fernald?
Sandbags. Glad we’re thinking outside of the (sand)box. For a few days, I thought we had a disaster on our hands…
Hanford is, in effect, a “dirty bomb”
“A dirty bomb is a weapon that combines radioactive material with conventional explosives.
The purpose of the weapon is to contaminate the area around the explosion with radioactive material,
Since a dirty bomb is likely to cause many deaths, many consider this to be a weapon of mass destruction.”
…..Wikipedia
There is no such thing as a safe dose. Just less dangerous doses.
The effect of irradiation exposure is cumulative. The emitting material itself does not multiply mass or output. Cumulative means the Damaging effect on living matter, in this case human, adds up with each additional exposure. In other words, the more total exposure the greater the risk of cancer and damage to gonads which results in birth defects. So if you get 6 chest x-ray doses today and never have another, well and good. But if this keeps being repeated every year, say from childhood, it adds up.
So if we keep having these meltdowns and dumps into the atmosphere of radioactive material that emits for hundreds to thousands of years it is eventually going to add up.
Related but from a slightly different perspective.the effects result in increases mutation rates. Mutations though occasionally are adaptive, most are destructive.
This storage is normally intended to hold the water pumped out from the suppression surge pool, when this wetwell goes into maintenance. So presumably under normal circumstances they stand empty ready to be used.
Line 3. They’re calling collect.
Boxturtle (*rimshot*)
I did a fair amount of activism work in the Hanford areas in the early through late 90s. James Acord, Pete Bevis and I took soil and water samples from the area on the western shore of the Hanford Reach of the Columbia, known to the superfund insiders as “N Reactor Springs.” Suffice it to say, the radiation is already getting into the river in small but varying amounts.
The way superfund monies are spent at Hanford is mostly a huge joke, mostly multi-million dollar contracts going to a small group of companies who pat each other on the back as they pass any meaningful cleanup action further and further down the road.
So there is no “Normal level of Plutonium”,,, in anything.
All that crap comes from humans trying to “cheat” nature with their atomic parlor tricks.
:-) :-)
The last Tepco press event for the day seems to be running very late. It’s 12:00 am Japan time and it hasn’t started. (They had one at 3 am once)
I’m not going to stick around since it’s 2am here already.
Very interesting paper posted here
It is a technical calculation that appears to be of good quality.
It argues that there have been small-scale, localized recriticality episodes in this accident. That means that we have been and perhaps still are closer to a sudden major release than has been explicitly stated.
This finding will change the discussion over the next few days.
bad linky
Also, I have access to some technical data (not on the web) from a nuclear operator. The containment vessel for these reactors were designed to handle pressures of 4-5 atmospheres. The actual pressure evidently got as high as 8 atmospheres.
I assume this is what led to the Unit 2 SPV failure on March 16.
Sorry, I’ll try again.
Very interesting paper posted here [PDF]
The paper rules out the other likely source of the “neutron beams” reported earlier, leaving recriticality.
THe Secret Of The Machine
“But remember, please, the Law by which we live,
We are not built to comprehend a lie,
We can neither love nor pity nor forgive.
If you make a slip in handling us you die!
Rudyard Kipling
I misstated the argument, sorry.
The paper works from the high reported values of radioactive chlorine in the effluent and concludes that the source of neutrons required to produce these levels is most likely explained by at least one occurrence of recriticality.
The reason for the calculation in the first place was the reporting of neutron radiation (called “neutron beams” in translation).
me: Other assays from TEPCO that indicated recriticality were subsequently revised/retracted. Watch for news about reported levels of Cl-38 being changed to follow the arc of this argument.
Great paper!
Of course, that’s where the chlorine came from. Duh. 37 minute half-life. So the leakage came from the reactor core (via plumbing), and recently.
If the Cl-38 is what they think it may be from, this is the worst news I’ve heard in two weeks. And depending on how they’re recirc’ing the water in 1,2,3 and considering they’re uncertain of the source for the water in the ‘trenches’… well, uncontrolled criticality in such an environment is not an option anybody wants.
I’ve got a better solution for everyone. Use Tea-Baggers instead of sand bags. They’re so fucking stubborn that they won’t budge. And they could absorb all the hazardous radiation.
It’s a win-win.
Well, not not much of a shock. I knew there was a reason they weren’t releasing detailed isotope breakdowns.
It is possible that there are reactions occuring in the melt that we simply aren’t aware of or that occur at different rates under extreme conditions. Remember Castle Bravo!
However, I am inclined to believe that there have been multiple recritical events. It is even possible that some of the reported hydrogen explosions are incursions.
And the conditions are still them same (more or less), so additional incursions are possible.
What we have working for us is that when an incursion happens, the physics of the event will result in the core geometery changing until there is no longer critical mass to support it. This happens very quickly, on the order of milliseconds.
Boxturtle (And it also points out that we have no real idea of what’s happening in those cores)
Argh! That was supposed to a be a reply to Lobster. And I know I hit the right reply button. How long must we continue to suffer under this hideous interleaving?
Boxturtle (Surely there’s someone here who could donate enough time to fix those fscking style sheets?)
I have this vision of radioactive, mindless, brain-eating, teabagging zombies.
Boxturtle (No, I’m not currently watching Fox)
Night of The Stupid Dead!
It is unquestionably the worst news we’ve had since this started.
Speculation:
1) Every one of the neutron ‘beams’ is a result of an incursion.
2) This is part of the reason the US has a much wider evac zone. We’d KNOW if there’d be recriticality.
Boxturtle (Betting we won’t see any new isotope data)
What exactly is an incursion?
Warning: Cynical mode on.
An incursion is a polite way of saying a portion of the pile went critical and generated an ‘event’. An event is a polite way of saying explosion, neutron beam, or large radiation release.
So we can say “This event was caused by an incursion” rather than saying “The core went out of control recritical and caused a large explosion”.
I’m not sure the word was used in this context prior to Chernobyl.
Boxturtle (What’s a polite way of saying “we’re so screwed”?)
One danger they don’t seem to be talking about much is the nature of radioactive particles, which actively emit emit the radiation (depending on half-life, etc). In the event a person ingests such a particle, that specific particle would continue to give doses of radiation to the person until their body manages to flush it out (or dies). I was under the impression that avoiding the ingestion of these particles (vs. blocking actual radiation) was the purpose of the protective clothing being worn by the workers.
If minuscule radiation levels were just passing us by as energy, it would be one thing. I worry that the ton of little particles *emitting* the low-levels of radiation being detected could be ingested (either through food or lungs). That might stick with folks a bit longer than desired.
I live near several “downwinder” communities to the Hanford complex. It has been pretty well demonstrated locally that contamination has a tendency to concentrate based on prevailing winds/land features/etc. rather than evenly diffuse (even Spokane still has a couple “hot spots”). While the industry will never ADMIT to people dying from the crap they’ve done, this area was one big human experiment. The results were not exactly improved health and longevity for the local citizenry. As with the natural environment, the body tends to concentrate these pollutants in the filter organs. The more particles ingested, the higher ultimate concentrations that continue dosing the patient (not even discussing the actual toxicity of this stuff beyond radiation).
This is a mess on top of a mess on top of a mess, IMO they AREN’T being entirely forthcoming.
Powwow, regarding the comment you’ve reposted above from Millie Sievert…did s/he include a link, or refer to the source, for the particular details pertaining to the water in the trenches? It would be good to have confirmation/verification.
Changes in the (freshwater, with boron) water flow being pumped in to cool each reactor unit’s core, per NISA on Tuesday, March 29:
It seems clear both from the comments excerpted and from other comments in Scarecrow’s preceding post that “Millie” is helpfully relaying information gathered from domestic Japanese media reports in Tokyo. Thus any link wouldn’t do us much good, unless we could read/understand Japanese. I have seen identical information about the distance of the water from the tops of the trenches reported in English by Kyodo News, but have seen no English-language reporting about the total depth of those trenches.
kgb999@9:29, really accessible and really helpful. Thank you.
Which is why details such as the total trench depth relayed by “Millie” – otherwise available only to the domestic audience in Japan – are so helpful.
I just came across the following at a blog called The Automatic Earth:
I don’t read Japanese, so I can’t vouch for the accuracy of the translation. What more can we take from this information-wise?
I agree that a momentary recriticalization would release a lot of energy but it does not inexorably follow that there would be a (steam-driven) explosion.
So far, the only known explosion related to a containment breach was when unit 2 had the 6-ish AM SPV incident. That did not drive a large explosion.
Could there have been recriticality in the SPF on the service deck of unit 4? Maybe, but the explosion there was still most likely hydrogen-driven.
Let us continue to be clear (so as not to increase the dread factor well beyond what is physically possible) that there is NO chance of a nuclear explosion at the Fukushima site. The wrong set of isotopes are there. Having said that, the problem with recriticality is that the heat load goes up fast and they are almost certainly (certainly!) unable to handle that, so things break, perhaps violently. Unless there is some kind of inverse Capricorn-1 going on, there has NOT yet been a really big steam explosion at Fukushima.
And to be clear: I have found no evidence of a recriticality event @ unit 4.
I don’t recall timeline data for the 13 neutron readings. Perhaps they were all at the same moment. If there were, and if that time was a few minutes after 6 AM that morning, then it would be very interesting indeed.
And yes, the worst news in two weeks for sure.
Here’s why: So far, the actual damage to humans from this nuclear event is small. Even the damage to humans associated with draining that trench into the Pacific would be small. And I mean small compared to the 1000 or so American coal miners who die each year from black lung disease, never mind the asthma, etc.
Finding out that we are perhaps still teetering on the edge of recriticality and the source of energy that represents is horrible. The *good news* in that scenario would be that all that radioactive reactor water would be continuously released for weeks, compared to the potential bad news.
I wonder if they can correlate the neutron observations with the introduction of unborated seawater to one of the reactors?
Can anyone find the timings for the neutron observations? I have the timelines of water injection operations saved.
Reactor core breached in Unit 2. Meltdown underway.
http://drich13.newsvine.com/_news/2011/03/29/6368965-us-expert-warns-meltdown-is-underway-in-japan-2-reactor-vessel-breached
This isn’t the best article out there on the subject. I believe (read on FB) that there is a confirmed report somewhere, but there was no link.
No chance of nuclear explosion whatsoever. Assuming a chunk goes recritical, the heat generated from the reactions would expand the chunk enough to end criticality in microseconds.
Boxturtle (All bets are off if the core is liquid, but you still don’t get an nuclaer blast)
Lobster? Scarecrow? BoxTurtle? Beuhler? Anybody?
Meltdown.
This was posted at The Oil Drum
http://www.guardian.co.uk/world/2011/mar/29/japan-lost-race-save-nuclear-reactor
But then someone else said this was old news. Well, I’d heard of breaches, but not in this form. It was new to me. It sure hasn’t made headlines. Seems like it should be.
Hard to say what this is. There has certainly been a partial meltdown of the fuel rods with probable continuing evolution of the fuel now and then since 11 March.
There is not a real meaning to the words “full meltdown”. It could mean more of the rods melted than the earlier estimates indicated. It could mean that someone out there has evidence that the concrete containment has been breached by hot fuel.
Earlier in these threads, I said that there was supposed to be a very thick concrete floor under the reactor pressure vessel; breaching that with hot fuel would take a long time (but might be hard to stop). I do not believe that is what any experts are talking about now (could be wrong).
From plant schematics that I found (offline, sorry) the thick concrete slab does not appear to extend very far outside the diameter of the reactor pressure vessel (RPV). If the RPV has a hole in the bottom and the fuel is dripping down, there appears to be a thin concrete slab not too far away. That would not take as long to penetrate — but I do not see any evidence that that has happened, either.
I do think the situation is unstable and evolving, and that there is a very, very unfortunate tension between the need to inject a lot of water into these units to prevent continuing fuel melt and the fact that there are leaks from somewhere to the environment (the trenches, but also into the air — look at all the volatilized I-131 readings). Given that tragic tension, what has to be sacrificed is the local environment. I.e., you have to keep pumping water in, regardless of whether it is spilling onto the ground, turning into steam, or pouring into the ocean, because the alternative (mobilization of the tons of fuel in the RPV) is much, much worse and virtually CERTAIN if you stop the cooling.
Okay, this Guardian article goes further and argues that the fuel itself is now on the concrete slab. If he is right (and he is speculating, with information and expertise) the next question is whether the process is accelerating or not. He thinks not.
In the early days of this accident, we linked up reports to deficiencies of the shape of the concrete flooring, at least for unit 1. In newer designs, the floor is sloped in such a way that corium (hot, molten fuel) spreads out as it drips down. I recall posting or reading that this was not the case for unit 1. I’ll send a dollar to anyone who can find those discussions of the design of the concrete pad.
My recollection is that the fuller appreciation of the dynamics of a core meltdown did not exist in the 60′s (when at least unit 1 was designed) and that no upgrade of the floor was done.
Q: What is the nature of the concrete flooring in Unit 2? How thick? How shaped? Is it boronated concrete (that could help by absorbing rather than reflecting neutrons)? Are there any neutron measurements inside the containment that are live?
Note that if there is a dramatic (i.e., explosive) turn of events, it could still take days to get there. If it does get more dramatic, it will only be the beginning, because it will be that much harder to stop the same problems from happening at units 1 and 3, and in the fuel assembly in the spent fuel pond @ unit 4. And unit 5, and unit 6 if the drama is really serious.
Another question for the Guardian speculator would be, how does this process end? Do they have enough boric acid on site to absorb any neutrons that be released? In short, once the fuel is on the slab, would there be a tendency for the accident to stabilize or continue?
In the above citation, Asahi Shimbun News referred to: “a vertical duct that is 15.9-meter deep”; I’m assuming AFP is referring to the same thing in the following March 28th story, which describes: “a 15.9-metre access shaft”.
With respect to the height/depth of the actual TUNNEL, AFP says: “Each reactor turbine building is connected to a maintenance tunnel large enough for workers to walk through”. Yikes.
Here’s the AFP story: Highly radioactive water spreads at Japan plant.
I haven’t had a chance to read the rest of the article closely. I hope it helps flesh out the picture.
Are we dealing in this instance with recriticality, then?
And if so, what are the potential consequences of fuel interacting with the water that I assume is on the floors of these buildings? Are we looking at another hydrogen explosion that could scatter corium?
“Fuel on the slab” is the same as “core on the floor”?
My other question is this – with a catastrophic breach of containment in any 1 reactor, do they have to abandon the site? Will this mean cooling attempts cease?
Government Responds to Nuclear Accident by Trying to Raise Acceptable Radiation Levels and Pretending that Radiation is Good For Us
http://www.washingtonsblog.com/
The Cl38 paper is very interesting. It seems to rule out that the Cl38 could be produced by spontaneous neutron emission.
I did not see a calculation of the converse, which would be basically the time integral of kg.s of recritical mass needed to account for the amount of Cl38 seen. Did I miss it? If not, has anyone looked into it? Is it a plausible number?
It appears (see citations in my comments below), per Reactor #2: there is a VERTICAL DUCT/SHAFT that is 15.9-meter deep/high. The TUNNEL height is specified as high enough for workers to walk through. It’s length is 76 meters.
TEPCO estimates there is: “several thousand cubic metres of water inside the tunnel”. So, it appears the tunnel is completely filled with water; and the 15.9 meter vertical duct has water up to “1 meter from the top”.
Maybe these distinctions are meaningless. I’m just stating it for clarity’s sake.
Insufficient information in the article’s I’ve found. It’s not clear to me even if this is NEW information or old.
If a melted core were to hit water, the water would flash into steam at once. Then the steam would split into hydrogen and oxygen. You’d probably get a hydrogen explosion at that point. The corium would be a thick liquid at that point and would probably splash everywhere.
Boxturtle (I’m with lobster, situtation unstable and evolving)
Unknown. If the core simply drops into a dry basement and the current structure isn’t damaged any more, operations everywhere else could probably continue.
That said, I think if the containment cracks enough to release corium the site would have to be abandoned. The odds are that there’s no such thing as a dry floor there, the melt would hit water and product a huge cloud of radioactive steam and possibly a hydrogen explosion.
Boxturtle (They’re running out of time to break it to us gently)
My thoughts, the more I consider it, lean toward a steam release. With the amount of damage done by the initial hydrogen explosion and all of the breaches and cracks we’re hearing about at Unit 2 I’m not sure there is sufficient containment to create the pressure necessary for an explosion. We’re likely dealing with atmospheric pressure in and around the entire unit.
i’m starting to lose my way here ( not that that would be a bad thing),
- re “meltdown”:
my understanding was that neither zirconium “bottles” that contain nuclear material nor that material itself in the form of pelleys ever “melts”.
“meltdown” then is a misleading metaphor?
- the zirconium that contains the fissionable pellets can undergo changes in its compostion/molecular structure that render it “eggshell-like” and thus fragile cf 1726cc
would this mean fragile enough to shatter if a rod fell to a concrete floor, thereby scattering its pellet contents?
- now, befuddled, i wander up to to “recriticality”? scattered pellets are close enough to each other to ?
to do what?
get very hot?
fission into other elements?
- but the atomic chemistry of nuclear material forces them to “push apart” in fractions of time cf. box turtle ?
- “recriticality” is, therefore, merely an event to be expected in a problem like at fuji—
it’s just its magnitude that counts?
or, it’s a rare and dangerous event?
- then, there’s thar potential for explosive spread of radioactive material from explosions created from raw oxygen and raw hydrogen generated from the water covering the cracked rods and their pellet load?
yikes! i’m evacuating.
Fox has picked up the story.
http://www.foxnews.com/world/2011/03/29/workers-japan-nuke-plant-lost-race-save-reactor-expert-says/
Boxturtle (Okay, THIS is the worst news so far)
Okay, one at a time.
It melts. It’s called corium. http://en.wikipedia.org/wiki/Corium_(nuclear_reactor)
Yes, it could shatter and scatter the pellets.
Recriticality can occur when the core melts into a blob of corium, like lava. The blob is composed of the fuel and anything that hasn’t vaporized. It’s naturally very hot, and emitting neutrons. You get enough neutrons in the right place and you can restart the chain reaction. This can generate heat in the 10′s of thousands of degrees. Heat makes things expand, so that area of the melt will expand and change shape until it’s no longer critical. At those tempratures, that happens rapidly. It happened at Chernobyl, did not at TMI.
Boxturtle (Nowhere to run. I’d take up smoking and have a double helping of Alfredo)
While the fuel rods in the reactors may not be fully covered, there is still water in there. Isn’t it at the bottom of the RPV? If pellets have fallen from disintegrating fuel rods, wouldn’t they plop-plop-fizz-fizz into the water (boronated or not) at the bottom? If the pellets are close enough for any degree of recriticality, wouldn’t we see surges in temperatures and pressures as the surrounding water flashed into steam?
thanks for wading in and clarifying, box turtle.
“there is still water in there.”
Objection! Assumes material not in evidence. No steam explosion reported, no massive increase in radiation reported.
The pellets are hot enough on their own to flash quite a bit of water into steam.
If things went recritical, we’d sure see a temp. increase IF we had instruments pointed in the right direction. I doubt we’d see much of a pressure increase, the containment is breached.
I point out we are WAY into brand new territory here. Nothing like this has ever happened before and even the informed opinions are based on what was learned before.
Boxturtle (I’ll probably have to eat some of my words. But I’ll be in good company)
“Fuel on the slab” is the same as “core on the floor”?
Yes
Assuming containment is sufficiently breached, are we less likely to see an explosion because pressure is being released via the breach?
I believe that no isolated fuel pellet can go critical, even if it melts. You get new heating (criticality) mainly from having enough fuel get away from the stuff in the control rods that has been absorbing the neutrons. Think about this way: they restart the reactor simply by pulling out the control rods. If you instead move the fissile material away from the control rods, you can get the same effect… IF you have something to slow the neutrons down. (In this kind of fuel, they come out at high speed and typically fail to cause another fission reaction — so nothing special unless you slow them down.) Ironically, the very water that is being used to cool the fuel is also an effective moderator of fast neutrons. I.e., they slow down and tend to cause more fissions, releasing more neutrons, etc, as long as conditions persist (uranium in proximity + water).
One way you try to shut this scenario down is by adding boron to the cooling water. As long as they’ve been doing that, the boron vacuums up (i.e., captures) enough neutrons to stop the chain reaction from continuing.
One of my musings above should make more sense to you now: I wonder if the neutrons that were detected were detected when the first seawater was injected into one of the units which was already in partial meltdown. Point being, the seawater (wasn’t? probably wasn’t?) boronated, so you might have had conditions for neutron moderation + fuel moved away from control rods. If that occurred, maybe only a little fuel was involved (because we did not see a gigantic rise in the heat source). It would have started raising the pressure in the vessel and if that pressure was not vented, would have broken something.
This depends on how much heat is generated. In theory, it would be possible for a small bit of the fuel to have begun to chain react, thereby releasing only a relatively small amount of energy. Maybe only a little bit of fuel is far enough from the neutron absorbers to heat up. Normally, one might expect something like this to be enough to lead to real complications quickly, but that isn’t required. You could have simply had a “spark” for want of a better analogy.
On the other hand, I found some calculations and results of experiments in the US online the other night (working from the MIT site) that showed the rate of concrete ablation by a hot core was actually really slow. So it could be sitting there, a glob of very hot gooey metal at the bottom of a pool of (hopefully boronated) water, not doing very much. Many unknowns here (in principle, not just what we aren’t being told).
I understand the seawater was boronated.
http://arstechnica.com/science/news/2011/03/understanding-japans-nuclear-crisis.ars/2
Sorry – last line of third paragraph in that article. (Note I don’t know the original source of this information. I’ll look through some Japanese sites later).
Good question, Prof Foland. I have not seen the reverse calculation. That would at least set the scale of how “localized” the proposed event could have been.
“I believe that no isolated fuel pellet can go critical, even if it melts.”
It’d take a LOT of fuel pellets. Minimum critical mass at perfect sphere is over 20lbs and that’s for pure U235. This stuff is less than 10% fissle, even allowing for weird MOX mixes and fission products.
You’re only in danger of recriticality if you melt it and stir it. How much danger? I dunno, two prior meltdowns is not a sample size.
I hope your musing is correct. That would mean this is old news and things haven’t got worse.
Boxturtle (And they’re just now admitting what they’ve always know)
Yes, I agree that there are reports that the seawater was boronated. However, if you go back through the TEPCO reports, they specifically report boronation only at various times in various units. It does not appear to have been continuous. In particular, in the same report you will see that they boronated the water in one unit but do not mention that for another (so it is not the case that some days have that detail and other times they just fail to mention it).
Also, there were tons of boron airlifted from France at a certain point (linked in the threads before this one). At the time, that suggested problems with the onsite supply.
YYSyd,
How were these “trenches” described in the press conference?
Were they described as open to the elements, as you suggest? Or are they actually mostly underground tunnels?
I tried to get some clarity on this in comments I made upthread about “tunnels” and “vertical shafts”.
Oh I don’t know, BoxTurtle. Recriticality at any point after March 11 scares me greatly. I did not think it was particularly likely to rekindle that particular heat source. I have been hoping that this was ONLY about continuously removing decay heat.
Plus, as you said, if it happened once, it could happen again. Whatever the consequences were before, they clearly could have been worse.
Faux news says someone out there is getting desperate:
Probably the fact that this is coming from the anti-news station is itself good news.
Depends on what you mean by catastrophic. This is the definition of catastrophic (no joke) in my book. That is, the situation would be catastrophic precisely IF the site has to be abandoned, because then you several more of whatever the first event was as the unattended reactors do their thing.
Lobster,
Remember a day or so after the earthquake/tsunami, when SOS Clinton said the US had sent “COOLANT” to the Fukushima plant. Then, her statement was retracted within 24 hours.
That little episode was fishy — it had an air of something far more significant about it.
Could the “COOLANT” Clinton was referring to be BORON? And what are the chances the US did send boron from the get-go? What would that suggest about what the USG knew and when they knew it?
millie sievert,
the first part of this article is very helpful for a layperson strugging to understand.
tx
p.s. i love your pseudonym – smile every time i see it :-).
Maybe not. FOX has more than one axe to grind — or more than one energy industry executive to blow.
SOMEBODY oughta to be getting desperate by now. Yeah, pump it to an offshore tanker. Better be one of those new expensive double hulls…that you don’t want to use again.
Boxturtle (Bet when it gets into the ocean they’ll tell us it’s not at dangerous levels)
Further to the foregoing…
Reuters, March 11, 2011, U.S. delivers coolant to Japan nuclear plant: Clinton:
—————————————————————————–
REUTERS, March 11, 2011, UPDATE 1-US did not deliver coolant to Japan nuclear reactor:
France was also prepared to send boron the day after the earthquake/tsunami; but Japan, evidently, did not accept shipment until a week later. Here’s the story from TIMESonline, March 17:
Helpful updates and detail from another Japanese media outlet reporting in English:
Which was followed by this report:
Also see this Yomiuri article detailing the miserable conditions for employees on site, who are packed inside an unventilated earthquake-resistant building completed last July (located about half a kilometer NW of Unit 2) – their lousy food and sleep are probably unnecessarily adding to the increasing risk for human error by the exhausted workers, even as margins of safety in case of such error diminish:
http://www.yomiuri.co.jp/dy/national/T110329004944.htm
I certainly agree that the French offer was significant. I have also wondered if the “coolant” Clinton was talking about was boron. There is no such thing as a magic coolant. I assume she did not make up the whole offer out of thin air. The most likely item on offer would have been boron.
Does it mean that they knew from the first day what was at stake? On Saturday morning after the quake, there were already reports of I-131 and Cs-137 in the atmosphere. That was a very dangerous early sign. The UCS group later argued that that early finding might not have signified a breach. As I recall their line of thinking, the same error (lid subjected to too much pressure) that plausibly put the hydrogen in the outer containment building instead of through the vents that would have been the expected pathway, could have led to trace amounts of I-131 and Cs-137.
I could not understand exactly how serious the situation was in the first 24 hours because the amounts of iodine and cesium that were detected were not stated. Trace levels only? Bad but not catastrophic. Much more found? Probably already an inexorable chain of events underway, probably reaching full potential in the first 48 hours, when the decay heat was highest and the batteries were already dead. The seawater injection idea was a huge, huge sign that there were very serious problems that might not be controllable. We are still in that state. There has not yet been an idea put on the table that I have heard that would have a good chance of ending this without continuing radiation leaks. Bad news: the best case scenario itself has become bleaker as time goes on. Good news: the worst case scenario is also less likely as time goes on (even if there is “core on the floor” or “fuel on the slab”, though we are now in an essentially asymptotically flat state with respect to cooling requirements. Problem now is that the water required to stay where we are with respect to cooling seems likely to end up in the environment. My best case scenario involves using the ocean, even though that involves risks that I cannot really understand. In other words: the best case that I can think of that sounds technically plausible involves accepting a huge insult to the environment to avoid the risk of a much larger, more widespread, and ultimately greater insult to the environment that also involves much higher human health risks.
All I can say about those risks is that a lot of really stupid people have already stuffed an enormous amount of radioactive material into the ocean and we’re still here. That’s a topic for another discussion, though.
The point of my second paragraph:
If the amounts of iodine and cesium were on the large side from the beginning and that was communicated to the USG, then yes, they knew more about the seriousness of the situation than we did.
One certainly imagines that the amounts were known, by the way. The question is only whether the amounts were on the large side on Saturday morning (US time).
The game at that point will be to talk about the dilution and the low local levels rather than the total amount. There is some truth to that point, but it is nevertheless obfuscatory.
The other kind of story that will come out at that point is that putting this stuff in the ocean is better than the other two alternatives: leaving it on land (air is really bad for a variety of reasons; remember the explosion in unit 4 was 99% likely due to air + zircaloy and there is still a lot of zircaloy that hasn’t met that particular fate) or letting it slowly leak out and be distributed widely by the wind.
The kinds of good ideas that could still materialize sound crazy to me but I’m not an engineer. For example, make a new sort of closed-loop cooling system by fashioning a new containment for the cooling water out of anything available (big ship? supertanker?). If you think about all the ways that water can get out of things and add in the extraordinary difficulty of working in the radiation field around unit 2, I just don’t see it. Moreover, if you try something crazy like this you could run out of luck and face a much wider dispersal of the radioactive onsite inventory. Right now, they are one failed pipe or valve or so away from bad going to worse.
Does someone know about this? 323 C sounds high to me. I recall alarm just 3-4 days ago about ~400 C.
The higher the temperatures drift, the more you can be sure that either (a) the alternatives are really unpalatable or (b) they can’t do anything about it, because everyone on site knows that certain control of the reactor cores remains the highest priority.
See, for example, this composite TEPCO report.
The pattern of reporting for when boric acid was injected into Unit 1 includes the combination of seawater + boric acid. The Unit 2 reporting, on the other hand, suggests that when seawater was being injected there was no boric acid.
Note also that if they were working under the assumption that the cooling system was closed, then the volume of boric acid in chamber would constant. (I know nothing about whether boron would be volatile and come out with the steam in the “feed and bleed” operation). My point: Unit 2 had a known or suspected rupture in the SPV (large toroidal water storage chamber) long before the report explicitly says they resumed adding boric acid. Could it be that the volume of boric acid went much lower than expected when the SPV rupture occurred?
Keep in mind that we are pretty deep in the weeds here. There may not have been any recriticalization event. The Cl-38 level is a mystery, but so was the earlier report of I-134, which was retracted.
Cl-38 is beta (directly to stable Ar-38 so no follow-on decays), and those are much trickier to fingerprint than gamma emitters. Thinking about that, I came across an interesting note on false positive nuclide detection which might be useful to bear in mind when reading the Cl-38 paper. All that said, the Cl-38 decay is pretty hefty (almost 5 MeV endpoint.)
I think a bad TEPCO measurement is at least as likely as recriticality.
Figure 1 is particularly interesting, as an example of how three “expert reviewers” can sign their names to an abject failure to assess even an obvious mis-fingerprinting.
285C is the temp when operating normally (courtesy of Nikkei).
Here’s a link to a report by Steven Hodge at Oak Ridge on the the meltdown sequence of Boiling Water Reactors of the type built and used at Fukushima in Japan:
http://www.osti.gov/bridge/servlets/purl/6124656-R8y05j/6124656.pdf
Table 1 makes clear that the expected time from electrical power loss to loss of containment is 15,300 seconds, i.e. 4 hours 15 minutes. I may be wrong, but I think the black-outs lasted much longer than that for all six reactors.
Therefore one must ask; how many of the reactors at Fukushima +didn’t+ lose containment?
Was the event at #3 in fact a meltdown/steam explosion?
Lobster,
If it’s a matter of reconfirming the data via an additional source, NHK reported those same temps in a story earlier today, March 29, 2011: Leaked radioactive water hampers cooling of plant:
I just read some of the detailed plant reporting here (PDF).
Looks like this temperature is fine. The pressure is currently well below the design point and thus also even further below the maximum point.
I’m going to do the broken-record thing and say that the pressure indications we’ve seen to date all say they are running at 3-4 atm, not at the normal operational level of 58 atm. So seeing 285C is not indicative of simply normal operations. At 3-4 atm water boils at ~125C, which is actually consistent with the RPV bottom head temperatures that are measured.
In fact, I just noticed that the RPV being at 3-4 atm is what you would do if you thought there was a breach to the containment, because the containment is designed for that range of pressure.
AFAIK nobody has really cleared up where the “feedwater nozzles” are and why their temperatures would be much higher than the expected water temperatures. My take is that it’s probably evidence for a very strong temperature gradient across the steel RPV. In regions which are in contact with a large water mass, the RPV is at the water’s temperature (i.e. its boiling point.) In other regions, the RPV is much hotter.
Also, I think the supression surge “pool” which I mentioned earlier is actually a tank (Nikkei Newspaper is calling it the Pressure Supression Storage Tank).
Nikkei is saying that water from #1 is getting pumped into the condensor located in the turbine room of #1.
Water from #2 and #3 are getting pumped into the condensor storage tanks (one for each reactor – located outside the turbine room). From these two tanks the water will get pumped into the Pressure Suppression Storage Tank. If that becomes full, they are considering building another onsite pool or tank, and also considering moving the water to a tanker. (Coincides with what Lobster previously mentioned).
Thx
I wish we could get some ongoing readings of the fallout here in the US. I read at Bradblog that the EPA was shutting down some monitoring stations in CA due to high readings.
That is encouraging. How do you find this stuff?
It’s 4 hours if you keep it at full operating pressure (58 ATM) for the whole time. The report says the pressure is 95% responsible for the failure, so if it gets depressurized fairly early then that risk should be much reduced (and the relevant timescales much increased.) We know they depressurized at some point quite early; someone who’s kept a better timeline than I have probably knows when.
lobster@ 5:03
In addition to everything else you provide, appreciate you sketching out some of the options at a high level.
If diluting in the Pacific is the eventual solution/tragedy, I would offer a renewable form of electrical generation that is normally destructive of the environment: tidal barraging.”
They generate electricity from tides. The first question is would tidal barrages even be feasible at Fukushima? I have no idea.
AFAIK, tidal barrages are essentially two dams. One captures energy at high tide. The other captures energy at low tide. Like any dam, they damage the ecosytem.
From wiki:
“The placement of a barrage into an estuary has a considerable effect on the water inside the basin and on the ecosystem. Many governments have been reluctant in recent times to grant approval for tidal barrages. Through research conducted on tidal plants, it has been found that tidal barrages constructed at the mouths of estuaries pose similar environmental threats as large dams. The construction of large tidal plants alters the flow of saltwater in and out of estuaries, which changes the hydrology and salinity and possibly negatively affects the marine mammals that use the estuaries as their habitat[5] The La Rance plant, off the Brittany coast of northern France, was the first and largest tidal barrage plant in the world. It is also the only site where a full-scale evaluation of the ecological impact of a tidal power system, operating for 20 years, has been made[6]
French researchers found that the isolation of the estuary during the construction phases of the tidal barrage was detrimental to flora and fauna, however; after ten years, there has been a “variable degree of biological adjustment to the new environmental conditions”
Some species lost their habitat due to La Rance’s construction, but other species colonized the abandoned space, which caused a shift in diversity. Also as a result of the construction, sandbanks disappeared, the beach of St. Servan was badly damaged and high-speed currents have developed near sluices, which are water channels controlled by gates”
If the worst scenarios playout, the negatives of the barrages appear to be in this case, positives.
Another option would be using the barrages to generate electricity to power the much better solution you suggested, the ad hoc cooling system you.
Nikkei also saying:
Reactor #1
Fuel rods exposed an estimated 160-165 cms.
Pressure in Reactor Pressure Vessel is 3.71 – 4.91 atmospheres
Temp in pressure vessel is 299 (top) 135 (bottom)
Pressure in Containment Vessel is 2.65 (top) 2.65 (bottom)
Reactor #2
Feul rods exposed 150cms
Pressure in Reactor Pressure Vessel: -0.25 (guage possibly broken)
Temp in pressure vessel: 160 (top) 143 (bottom)
Pressure in Containment Vessel is 1 (top), and too low to be measured (bottom)
Reactor #3
Fuel rods exposed 185 – 225 cms
Pressure in Reactor Pressure Vessel: -0.95 to 0.29
Temp in pressure vessel: 62.2 (top – guage possibly broken), 121 (bottom)
Pressure in Containment Vessel is 1.075 (top), 1.796 (bottom)
Data as at at 12:00pm – 1:00pm on March 29th. I think the data for the fuel rod exposure is their expert’s estimate of maximum exposure (i.e. they are not saying that the rods remain exposed as of now).
My opinion is that as soon as they vented contaminated steam to the atmosphere they lost containment and that continues to be true. Loss of structural integrity in the reactor vessels is an even worse part of this ongoing disaster.
obster@ 5:03
In addition to everything else you provide, appreciate you sketching out some of the options at a high level.
If diluting in the Pacific is the eventual solution/tragedy, I would offer a renewable form of electrical generation that is normally destructive of the environment: tidal barraging.”
They generate electricity from tides. The first question is would tidal barrages even be feasible at Fukushima? I have no idea.
AFAIK, tidal barrages are essentially two dams. One captures energy at high tide. The other captures energy at low tide. Like any dam, they damage the ecosytem.
From wiki:
“The placement of a barrage into an estuary has a considerable effect on the water inside the basin and on the ecosystem. Many governments have been reluctant in recent times to grant approval for tidal barrages. Through research conducted on tidal plants, it has been found that tidal barrages constructed at the mouths of estuaries pose similar environmental threats as large dams. The construction of large tidal plants alters the flow of saltwater in and out of estuaries, which changes the hydrology and salinity and possibly negatively affects the marine mammals that use the estuaries as their habitat[5] The La Rance plant, off the Brittany coast of northern France, was the first and largest tidal barrage plant in the world. It is also the only site where a full-scale evaluation of the ecological impact of a tidal power system, operating for 20 years, has been made[6]
French researchers found that the isolation of the estuary during the construction phases of the tidal barrage was detrimental to flora and fauna, however; after ten years, there has been a “variable degree of biological adjustment to the new environmental conditions”
Some species lost their habitat due to La Rance’s construction, but other species colonized the abandoned space, which caused a shift in diversity. Also as a result of the construction, sandbanks disappeared, the beach of St. Servan was badly damaged and high-speed currents have developed near sluices, which are water channels controlled by gates”
If the worst scenarios playout, the negatives of the barrages appear to be in this case, positives.
Another option would be using the barrages to generate electricity to power the much better solution you suggested, the ad hoc cooling system you.
I don’t believe reports like that.
Here is a UC-Berkeley website for rainwater readings.
And
Here is a UC-Berkeley website for air monitoring.
The tables at the bottom of each page are dense but have understandable information.
There are independent readings like this from all over the place. Radiation cannot be hidden from us.
My understanding (and I would be happy to be wrong) is that there are partially uncovered fuel assemblies in the cores of units 1, 2 and 3. This is indicated by the negative signs in front of the water depth in the tables. Positive is depth above the fuel assembly and negative is distance to top of water.
I don’t know why I think that exactly. I picked it up here from someone.
Thanks Lobster, them Commies at Berkeley will keep us informed.
Thanks! That’s the first I’ve seen that makes clear the “feedwater nozzle” is on top. So I think I declare victory in my description above about water temperatures, temperature gradients, and the pressures in the RPV’s.
I don’t know how pressure can be “too low to be measured”. That would normally mean 1 atmosphere.
I’m not quite clear on how the top can be hotter than the bottom. Radiative heating from exposed fuel rods are one way. Superheated steam that does not equilibrate as it comes up the water column would be another; it’s too afar afield for me to know whether either of those are quantitatively viable explanations.
Interesting, thanks. I assume that they want to find a home for the several hundred tons of reactor fuel that is onsite sooner rather than later. Building dams takes time. I am guessing there will eventually be a low-tech solution, along the lines of “dump the stuff in the ocean.”
Details matter and this would be an extraordinary route to take, but here are some examples of vaguely similar decisions that were controversial enough.
Low-level Rad waste dumping in the ocean.
More of the low-level rad waste dumping history
Nastier examples
There are undoubtedly more examples of people having this particular idea.
Lobster,
Here’s the TIME-LINE OF THE 13 NEUTRON READINGS, from Kyodo News, March 23, 2011: Neutron beam observed 13 times at crippled Fukushima nuke plant:
I thought you would appreciate that!
News alerts on KYODO News at 11:24
Water level halved in Fukushima nuke plant’s no 1 unit basement agency
radioactive iodine 3,355 times legal limit found in seawater near plant
Examples of negative signs for water depths in recent link from me (at 6:05) above.
Best candidate is unit 2. Unit 1 is still reporting a credible RPV working pressure. Unit 3 is in trouble, but unit 2 had the 6:15 AM event on 15 March that was evidently as likely a pressure problem as it was a hydrogen problem.
We should ask that guy that was in the Guardian. Did you notice his job description? Pretty good cred, assuming he still has all his faculties (and I have no reason to doubt that).
Good catch. I’ll be impressed when they halve the amount of water in the Unit 2 basement. That’s where the nasty stuff is.
should read 3,355
Good read thanks
But what about after you lay out the gargantuan quilt? And will it be made of superstrong spider webs?
(Actually I’m glad they are thinking about solutions.)
Brad didn’t say that, did he? Was it from his comments section?
From the report:
‘CREEP-RUPTURE FAILURE OF THE BOTTOM HEAD ITSELF’ (p.8)
‘However, about 95% of the wall stress +under normal operating
conditions+ (my emphasis) is due to the internal vessel pressure and the BWR Owners Group Emergency Procedures Guidelines [13] direct the control room operators to +manually depressurize the reactor vessel+ during a severe accident sequence long before the onset of debris relocation into the lower plenum.’
Since ‘debris relocation begins’ at around 8k seconds, surely the reactor vessel would have been de-pressurised prior to the subsequent events described in Table 1?
I liked the earlier comment about tea bags better. Then we could have a tea party and ummm, who could we invite?
the japanese working so had to control this problem face an “external” issue – earthquakes.
but that has already happened, you say. yes, but can the possibility of another large, disruptive earthquake following on the great earthquake ocvuring in the midst of this mitigation effort be dismissed?
probability? i haven’t a clue, but the large number of aftershocks (isn’t an “aftershock” just another earthquake?) since march 11 has been referred to as an “earthquake storm” – a fascinating term.
we humans have been living in a 12,000 year window of heat and light which has supported our extraordinary population growth as a species and the attendant extremely complex, but fragile, societies that growth generates.
the “heat” part of ” heat and light” is warming temps and glacial melt.
the ” light” part? lack of severely destructive volcanic activity.
New story at MOTHER JONES, by Environmental Correspondent Julia Whitty, March 28, 2011: The Radioactive Ocean.
I haven’t read this one yet, but Whitty wrote some extraordinary pieces about marine ecology/biology during the BP oil spill.
I hope you’ll comment further this evening Professor. It’s quite the ‘teachable moment’ here.
Quite the catalog!
Terrific, piehole. [Gotta always remember that comma]
That seems like a long way away from the source (through lots of concrete and stuff) to be associated with something going on in an RPV, but the dates are the right ones for the maximum risk of something like this. We should also go back to the timeline and see when the seawater injections started. Isn’t it amazing how complicated it is keeping track of six reactor cores and six spent fuel ponds?
Long-term prediction: nuclear reactors will be much less tightly clustered in the future.
TEPCO president hospitalized. Obama and Kan using the bat-phone (evidently for the third time since 11 March).
Kyodo
Lobster, fwiw I left a comment upthread answering your query about the timeline for the 13 neutron readings. Is there anything particularly remarkable in there?
Jesus, when is any/all of this going to make the FDL front page again?
Kyodo:
Massive power shortages projected for Japan in coming months: 15 billion watts lost from the grid.
[The six reactors at Fukushima were just a total of 4.8 billion watts. Other plants damaged were coal, dams, etc. Also some other nuclear plants remain off-line.]
Major industries may be slowed for the first time since 1974 oil shock.
—————————–
If this comes to pass, it will affect the global economy…there are already spare part challenges across the US and presumably elsewhere. Japan manufactures most automotive electronics (for many car manufacturers). Probably there are other niche industries that might be affected. If you have a lot of money, invest a few bucks for FDL and send it to Jane!
Did y’all hear from Meet The Press, on Sunday, that Obama called the military action in Libya a “turd sandwich”. That’s all I’ve got on Libya.
Detailed timeline of events in reactors here (PDF)
What I continue to see on all these documents is that they say they boronated the water for units 1 and 3, but they do not say that for unit 2.
Unit 2 seawater injection (which would be the reintroduction of unboronated water to the newly melted fuel, and so a very dangerous moment in general) began at 4:34 PM on 14 March. At 10:50 PM, they record dangerous pressure spikes. Containment is evidently compromised a few minutes after 6 AM the next morning.
Even with boric acid, the moment of reintroduction of water is a key moment. In unit 3, that occurred on 13 March @ 1:12 PM. Pressure spike followed at 7:44 AM on 14 March.
If we can find out more precisely when those neutron measurements were taken, we could probably eliminate some of these possibilities.
Yes, responses there.
Aha! The purposeful dumping into the ocean begins soon!
————-
Water in trench 1 isn’t the terrible stuff. But as John Candy said in Stripes, “We went to play bingo at the YMCA and one thing led to another…”
I read somewhere that the chance of an M7+ aftershock remains non-trivial at this point. The odds were highest in the first week or so.
They’ve got so much storage, and they keep injecting water. Triage. They will end up dumping the least bad stuff. Eventually, the least bad may be really bad.
NHK:
——————–
“considerable amount of time” == five years or more
if
“stabilize” == reach a state where they can be safely disposed of
——————–
This is a physics+health issue. You can see the pattern, though:
TMI accident: 1979.
TMI cleanup: 1985
Typical minimum residence time of fuel in spent fuel pond: 5 years
How do you stabilize a leaking spent fuel pond [unit 4] that has a full reactor assembly in it for five years? Take your eye off the ball once in those five years and you have a meltdown with no containment.
Bad.
I suppose you could build some robots to do something, but I can’t think of anything good to do other than build a new, more secure storage facility for the unit 4 SFP contents onsite, in the midst of all that wreckage and then move the whole mess over. Until then, a meltdown will always be lurking, just a few hours away. Less if a terrorist decided to fly a plane into the unit 4 wreckage.
Maybe you just build a new building that fully encloses the old building?
Of course, there is spent fuel in units 1-3, too, but it might be aged and movable sooner. Unit four is a special problem for the long term.
Chairman of Tepco two deputy presidents and a bank of senior management have been doing a press conference for the last hour and bit. The Chairman confirmed (and there’s no point in not) that units 1 through 4 are writeoffs.
The Guardian:
“Robert Peter Gale, a US medical researcher who was brought in by Soviet authorities after the Chernobyl disaster, said recent higher readings of radioactive iodine-131 and caesium-137 should be of greater concern than reports earlier this week of tiny quantities of plutonium found in soil samples.
But he added: “It’s obviously alarming when you talk about radiation, but if you have radiation in non-gas form I would say dump it in the ocean.”
Gale, who has been advising the Japanese government, said: “To some extent that’s why some nuclear power plants are built along the coast, to be in an area where the wind is blowing out to sea, and because the safest way to deposit radiation is in the ocean.”
Dump it into the ocean.
There is a 200 mile voluntary evacuation – the US government will pay for military family members to make it home.
That would include two air bases and one Naval base in Tokyo as well as an air base in Missawa, north of Fukushima.
What happens to Tokyo if the wind changes direction and comes from the north? A massive clean-up? Abandoment?
A good summary of the situation as of today:
http://www.dailymail.co.uk/news/article-1371375/Japan-nuclear-suicide-squads-paid-fortunes-battle-lost-reactor-2.html
IAEA reports levels of cesium more than twice that in the evacuation zone of Chernobyl up to 40 KM away from Fukushima, areas not evacuated.
http://allthingsnuclear.org/tagged/Japan_nuclear
@ Missouri Mule – As I read that article, it seems the author is saying that the levels around Fukushima are >2x the levels set in 1990, not twice the levels actually found on the ground in Chernobyl in 1986 (when the explosion happened). In any event its not a good place to be, and it is a serious problem. But if we are going to compare to Chernobyl it would be helpful to know the levels of Cesium on the ground in Chernobyl. Forgive me if I’m a bit defensive here. For me, accuracy of measurements (and headlines) is deadly serious.
Millie Sievert, did you follow news of the BP oil spill in the Gulf of Mexico this past summer? That was our own home-grown catastrophe and the consequences will still be in the making for decades to come.
As you may very well know, in late capitalist democracies, government is prone to weigh the public interest against private/corporate interests and, more often than not, government protects the interests of the latter to the detriment of the former.
During the Gulf Oil Spill, US government agencies, BP, and the mainstream media grossly, and repeatedly, underestimated the amount of oil spilled. They also grossly, and repeatedly, minimized, and misrepresented, the extent of immediate and projected long-term damage to the environment and its human and animal inhabitants. At the time, we sought out reputable independent scientists and seasoned environmental/political activists to give us accurate and honest assessments of the situation. In other words, we entrusted them to tell us the truth, and the truth happened to be bad news. When we went public with the bad news, a barrage of pro-corporate/pro-government commentators tried to muzzle us; they said we were ”exaggerating”, ”fear-mongering” and intent on causing ”hysteria”. Yet, the historical record will show we were on the right side of the facts.
Then and now, of this we can be assured: people who are willing to lie for profit are always afforded a much bigger bullhorn, and a much bigger platform, than people who are willing to tell the truth for free. Granted, there are times when we ‘little people’ may be tempted to overstate the case — but that is surely a misdemeanor compared to the rank criminality of the other, infinitely more powerful, side.
Mafr, wouldn’t you know it…The handful of nuclear power plants I’ve had the misfortune of seeing in person have all been on the ocean. The other day, when it became apparent that Fukushima will use the Pacific Ocean as a dumping ground, I thought, yes of course, THAT’S why there are so many nuclear plants by the sea.
Missouri Mule, thank you for the timely and useful information. I see no misrepresentation, or misstatement, of the data therein
http://english.kyodonews.jp/news/2011/04/82382.html
URGENT: Radioactivity 10,000 times the limit found from groundwater: TEPCO
TOKYO, April 1, Kyodo
A radioactive substance about 10,000 times the limit was detected from groundwater around the No. 1 reactor of the Fukushima Daiichi nuclear power plant, plant operator Tokyo Electric Power Co. said Thursday.
A Tokyo Electric official said the radiation level is ”extremely high.”
EPA: Radioactive Iodine Exceeding Maximum Contaminant Levels for Drinking Water Found in Pennsylvania and Massachusetts … But It’s Safe
http://www.washingtonsblog.com/2011/03/epa-radioactive-iodine-exceeding.html
Yes I wasn’t criticizing the article or the information therein. The issue of the 30km exclusion zone continues to be a hot topic here in Japan, and so that article is very germane to this discussion. What I was trying to point out was that if we say “levels of cesium more than twice that in the evacuation zone of Chernobyl” I would expect to see data corresponding to cesium levels in Chernobyl. However, the article is comparing standards instead of actual ground levels of cesium, and so I find the text in the post to be misleading. Is there 2x more cesium in Fukushima than was/is in Chernobyl? Its an interesting question to me.
With regard to the politics of this ongoing disaster, I would suggest that lying to the public is not a particularly unique feature of capitalist democracies. But the political dimension of this nightmare isn’t that interesting to me at this point – I think that will come in time. In any event, comparing ground levels of cesium would be a very useful thing to me, so if there is any data on ground cesium in Chernobyl I would be really interested to see it.