Understanding Radiation
In the last years of the 19th century, Henri Becquerel, along with Marie and Pierre Curie, discovered that some materials spontaneously emitted mysterious rays, like X-rays, that could penetrate matter and expose photographic plates. This property was eventually labeled “radioactivity” — a property that caused certain atoms to spontaneously break down and emit energy.
This was, frankly, a major shock: there had been a whole theory behind chemistry built up around unbreakable, indivisible things called “atoms” — the very name means “indivisible” or “uncuttable.”
But science recovered, and now radioactivity is something we’re used to, at least until something like the Chernobyl, Fukushima, or Three Mile Island accidents makes people think about it again.
Since we’re not faced with thinking about radioactivity in daily life, the units and methods of measuring radioactivity aren’t part of daily life either, not like weight and temperature are. As a result, many people get confused about them. The worst confusion, in fact, seems to be among people who are reporting about radioactivity and radiation in the media.
We would like to be able to get something as clear as a weather report, telling us how hot it is.The problem is, we’re used to the idea of temperature, we have some intuitions about it. We know that 104°F is a hot day or a high fever. But what about radiation exposure?
So let’s look at radiation in some detail and see if there’s something similar.
Becquerel and Roentgen and Curie, oh my!
Start off with Becquerel’s and the Curies’ discovery. Becquerel found out that a particular material known to glow in ultraviolet light, the uranium compound potassium uranyl sulfate, would expose a carefully wrapped photographic plate even through light-proof wrappings. Within a few years, Becquerel, the Curies, Ernest Rutherford, and others proved this radioactivity was being produced by a process that not only emitted energy but transmuted one “immutable” atom into a different kind of atom. These bits of energy came off in discrete packets, called “quanta,” and any particular transmutation produced the same amount of energy in the same form every time.
In fact, the radiation was normally in one of four forms, which we now describe as:
- “Alpha” rays, fast moving particles that are the nuclei of helium atoms stripped of their electrons
- “Beta” rays, electrons with no nucleus attached,
- “Gamma” rays, a form of very high energy X-ray,
- and free, fast-moving neutrons, one of the particles that make up the nucleus.
There are other forms, like free fast-moving protons, and more exotic particles, but they aren’t really important for this; the main four are enough to explain what’s happening at Fukushima.
Take a deep breath, we’re going to be underwater for a little while here.
How much radioactivity is it?
Of course, the first question we want to ask is “how much radioactivity is there?” and frankly, the news readers usually go astray right away at this most basic question. We measure the amount of radioactivity simply by measuring how often an atom decays and transmutes to another kind of atom, freeing some energy. The international unit used to answer the question “how radioactive is it?” is the Becquerel, named for guess who, and represents by definition one radioactive decay per second.
Another unit, named the Curie after Marie, or Pierre, or after both of them (there’s a fun little story of scientific politics that goes with that), is defined to be the number of radioactive decays from one gram of radium in one second, a really big number: 3.7×1010 decays per second.
The outcome of the scientific-political struggle was that a Becquerel is an inconveniently small unit, and the Curie is inconveniently large, so you’ll usually see numbers in tens of thousands or millions of Becquerel, or of milli- or microCurie — 0.001 Curie or 0.000001 Curie.
But how much radiation is it?
The thing is, for questions like health effects, we don’t really care about how many decays there are per second — we’re concerned with how much energy it transmitted to something else. If you’re having baseballs thrown at you, you don’t care how many are thrown near as much as you care how many hit you, and how hard.
When an X-ray hits an atom, it can ionize the atom; it knocks an electron off, giving it an electrical charge. So, to measure the amount of damage being done, we need a measure of absorbed energy. The first unit defined for this was defined as liberating a certain amount of charge in one cubic centimeter of dry air; this unit is called a Roentgen (or Röntgen, the more traditional way of spelling the name) and named for the discoverer of X-rays, Wilhelm Röntgen.
There’s a similar international unit called the Gray, which is defined by the amount of energy absorbed instead of the ionization produced. But since “standard air” absorbs energy as a known constant rate, we can compare Roentgen and Gray directly; it turns out that 1 Gray (Gy) is about 115 Roentgen (R). There is also an exactly comparable unit, of Roentgen absorbed dose (rad). By definition, there are exactly 100 rads to 1 Gray.
Why is there air?
Of course, people aren’t air, and there’s a complication for this whole measurement that different kinds of radiation — alpha, beta, gamma, or neutrons — transfer energy in different ways, with more or less efficiency. A fast moving neutron or alpha particle transfers a lot more energy when it hits than a gamma ray or an electron does. So there are defined units of “biological equivalent dose” that tell us the effect of a dose on a person. This is defined by using a “quality factor” or “weighting factor” for different kinds of radiation. Here’s a table of common weighting factors:
| Type and energy range | Weighting factor |
| electrons, positrons, muons, or photons (gamma, X-ray) | 1 |
| neutrons <10 keV | 5 |
| neutrons 10–100 keV | 10 |
| neutrons 100 keV – 2 MeV | 20 |
| neutrons 2 MeV – 20 MeV | 10 |
| neutrons >20 MeV | 5 |
| protons other than recoil protons and energy >2 MeV | 2 |
| alpha particles, fission fragments, nonrelativistic heavy nuclei | 20 |
(keV and MeV are thousands and millions of electron volts, respectively; an electron volt is a measure of a particle’s energy.)
Multiply the absorbed energy in Gray times the weighting factor and you get the human equivalent dose, measured in Sievert.
For our purposes, all the radiation types we’re interested in talking about in connection with the Fukushima accident are in the first row. But the other rows are interesting because you can see how the weighting factor changes for different kinds of radiation; in particular, high energy neutrons don’t do as much damage as the middle range. Basically, a high energy neutron finds it “hard to hit the target” — it’s likely to zip right through without transferring energy at all.
At least talking about Fukushima, all we’re concerned with are beta and gamma radiation, so we can just use a weighting factor of 1. One Gray, times the weighting factor of 1, gives a human equivalent dose measured in Sievert, so 1 Gy of gamma rays is 1 Sv of dose.
The American units for human equivalent dose are “rem,” which stands for “Roentgen equivalent in man.”
Dose rate: the “temperature” of radiation
Think about setting the oven. If you set it to 350, that’s hotter than setting it to 250, but if you put something in for 1 second, the difference doesn’t matter much. But baking something at 350 for an hour does more than baking it at 250 for the same hour. It’s not the temperature, it’s the total amount of heat that cooks the roast.
We usually confuse the amount of heat in something, and the temperature. In ordinary life, the difference doesn’t matter — materials are enough alike we don’t care. But not always, even so — a cake in a metal pan at 350 will brown more where it’s in contact with the metal than it will in a glass pan.
We could work through a similar series of steps, and go from the amount of energy available, to the amount absorbed, to how fast it’s transferred, and get a number that would actually be a lot more useful than just temperature, as far as letting us know whether we want to touch something or not. This number would be the “heat rate” and we’d know that something with a high heat rate is something we don’t want to touch. And with that, we’re finally coming around to our “how’s the weather?” measurement of radiation; the dose rate, or how much radiation energy we absorb per unit time.
The usual measure for dose rate is Sieverts per hour or rem per hour: that’s what really tells us how much effect the radiation will have.
Total Dose
The usual assumption is that the dose of radiation is cumulative in the same way. If you’ve absorbed 1 Gy of gamma ray energy, that’s a 1 Sv dose. Just as with baking, where a really slow heat over time will dry things out but not bake them, this assumption isn’t completely true; the body does repair radiation damage over time. But it’s easier to make this assumption, for safety’s sake and because without knowing more details of what was exposed, when, and by what, it’s hard to guess how much repair there will be. So we simply assume that the health effects of radiation are proportional to the total dose accumulated over our lifetimes, or over some long period like a year.
Now, at last, we have all the pieces we need to understand what’s happening at Fukushima. Start with the dose rate. This is the “how’s the weather” number. As of the morning of March 20 in Japan (the evening of March 19 in the U.S.) the dose rate was around 1 mSv/hr (0.1 rem/hr) at the main gate. Some locations, where some amount of radioactive material released appears to have landed and concentrated, it’s as high as 14 mSv/hr (1.4 rem/hr). A few places inside the plant were measured as high as 400 mSv/hr, or 40 rem/hr.
Now, by comparison, the normal background dose rate — the amount of radiation we absorb from the world around us — is 2.5-3.5 mSv/year — considerably higher here in Colorado, and higher still in parts of Australia, Brazil, China and India. In fact in Ramsar, in Rajasthan, the natural background dose rate is 260 mSv/yr — 100 times the “normal background” as we’ve defined it.
And 2.5 mSv/yr is about 0.0003 mSv/hr, so clearly at even 1 mSv/hr it’s considerably “warmer” than background.
But it’s still not that hot; by comparison, a normal chest X-ray is about 0.1 mSv, a mammogram up to 3 mSv, a CT scan can be as much as 13-15 mSv.
Here’s a place the news readers step on themselves: that’s total dose, not dose rate. It’s the difference between setting the oven to 350, and baking at 350 for an hour. The right way to think about it is to think about how long it would take to have the radiation affect your health. So at 1 mSv/hr, it would take 15 hours to accumulate the dose from one CT scan, and several weeks to accumulate enough dose to make much difference to health.
Making comparisons: the “banana equivalent dose”
There is an interesting way of comparing different amounts of radiation, and we’ve now built up all the pieces to understand it. Nuclear physicists and safety engineers sometimes use a unit called the “banana equivalent dose.” This is basically how it’s calculated.
First you take a banana.
Like pretty well everything in nature, bananas are slightly radioactive. Because bananas concentrate potassium, they are more radioactive than a lot of other foods — natural potassium includes some part that is the radioactive isotope potassium-40. That means eating a banana, and thereby ingesting the potassium, adds a measurable radiation dose from the radioactive potassium-40.
Now, before you change to kumquats or something, it’s not much, and bananas aren’t the only source. Potatoes are another food that concentrates potassium. But it does mean we can usefully compare the total dose we get from a banana with other small amounts of radiation. The somewhat-joking term for this is the “banana equivalent dose,” or BED.
In the earliest reference I can find to the idea of a banana-equivalent dose, a note attributed to Gary Mansfield of Lawrence Livermore National Laboratory works out the BED this way. By the way, I’m going to convert all the radiation amounts to Becquerel; Curies are a really inconveniently large number of this.
- According to the CRC Handbook on Radiation Management and Protection (pg 620), a “reference banana” is listed at about 130 Bq per kilogram.
- A “standard banana” weight about 150 grams
- So we get right about 20 Bq per banana.
When you eat that banana, the radioactive potassium enters the body; if you have enough potassium, the kidneys will flush it out within about a day, so for a short time you have that little bit more potassium in your body; you get some radiation dose from it. (You’re also getting a radiation dose from the radioactive portion of all the other potassium you have in your body, of course, but we’re just talking about this one piddling little banana.)
To really figure the dose-rate from being exposed to 20 Bq of Potassium-40, we’d need to calculate it based on distance, the specific energy of the emitted radiation, and so forth. You will, I’m sure, be pleased that I’m not going to explain that. Instead, I’ll refer to the excellent RadProCalculator on line, which tells us that one banana’s worth of radioactive potassium gives a dose rate of about 0.0037 µSv/hr. If the banana’s potassium stays in the body for about 24 hours, the total dose is 0.09 µSv. µSv times 10 gives µrem, so that’s 0.9 µrem — call it 1 µrem, what the hell.
So,
- the banana equivalent dose rate is about 0.04 µrem/hr
- the banana equivalent dose is about 1 µrem
- eating one banana a day for a year is about 365 µrem/year
Now is the time when we compare
Now, let’s compare this. We’ll assume that the normal background dose rate is around 300 mrem/yr. The most recent reports from Fukushima have dose rates at the plant of about 20 µrem/hr, so one hour at the gate is about 20 BED. (Again, be careful — a lot of the legacy media is reporting 20 millirem/hr; the IAEA has 2 µSv, or 20 µrem, 1/1000 as much.) Looked at another way, one banana dose for a year is 365 µrem/300 mrem — or just over 0.001, one tenth of one percent, of the normal background dose.
The 20 µrem/hr, over the course of a year (8760 hours) is about 1762 mrem — or about 6 times normal background dose. Which is about one-tenth a single abdominal CT scan.
The inestimable XKCD, interspersed with the usual comics, does some amazing scientific visualizations. There is a new one that clearly visualizes how much radiation (dose) we’re talking about.
Lots of interesting trivia in that chart; the big thing to remember is that it took three big changes in scale to get from the sorts of dose around Fukushima to anything like Chernobyl.
Slight mixup in your definitions:
rad = Radiation Absorbed Dose
rem = Roentgen Equivalant in Man
Yup, whups. I’ll add that to my corrections.
This article is complete nonsense.
First of all, anyone who compares what is happening in Japan with a CT scan or Xray is clueless. Both of those are over in an instant.
The correct comparison would be sitting inside a CT scan machine, and just letting it run nonstop day and night, because that is what’s happening in Japan.
Second of all, measuring the radiation in the air means nothing. If a piece of radioactive dust ends up in your lungs, the amount of radiation in the air is meaningless.
It’s about absorbed dose. Wherever and however it is absorbed.
First of all, anyone who compares what is happening in Japan with a CT scan or Xray is clueless.
Actually, anyone who accurately compares the two is doing a good job of helping people put Fukushima in perspective.
Well, people who have enough sense to know their own limitations and are willing to learn, anyway.
Joe, there’s almost always someone to pop and say that evil absorbed dose can’t be compared to good benign CT scans.
They’re always wrong.
An excellent explanation. One that is certain not to be heard on the likes of CNN, MSNBC, or possibly even Fox News (from whom I’d expect better).
The question, however, is not one of purely technical (and accurate) data. The really interesting question is, how many news organizations are getting it wrong due to simple lack of expertise, and how many are deliberately overstating the situation to frighten people into a BANANAE (Build Absolutely Nothing Anywhere Near Anything, Ever) response to nuclear power?
My money is on the latter. If it were mere ignorance, the law of averages states that at least some of them would be getting it right simply by talking to actual experts. But by a staggering coincidence, the “experts” they talk to come exclusively from groups opposed to nuclear power. (Or, in the case of the Sierra Club, or the present administration in Washington, any power at all.)
Which means that the MSM will continue to put out propaganda on this subject, while swearing with a perfectly straight face that they are telling the truth.
As the old saying goes, a lie can circle the globe while the truth is putting its pants on in the morning.
clear ether
eon
My guess is that the news people are ignorant, and the anti-nukes are diligent. I work up the other night and caught Fox talking to some guy at 3AM EDT about the latest panic piece — and who could they find at 3AM? A guy from Ploughshare, a strong anti-nuke group.
FoxNews coverage of politics is mostly fair and balanced. But when it comes to science and geography they are completely clueless with a few exceptions. They hire lawyers as anchors. There are only one or two with any sense of science or geography, or economics – BOR prime example.
I don’t find FOX fair or balanced. they do have a strong liberal / socialist bias in many of the programs. all in all they are not that conservative.
there are a few that are ..but they are in the minority.
Thank you!
Thank you, Charlie – it was a real pleasure reading something so truly informative after all the blah-blah-blah in the media lately!
This is more proof, as if any were needed, of the quality of education in our schools, particularly journalism schools. Graduates today are so uneducated that they do not even know what they don’t know.
And after all, isn’t that why we educate ourselves?
Helpful discussion. You were less clear in the discussion of the weighing factor. I think that I read that the higher weighing factor the less damage. I recall that an alpha particle can usually be stopped by a layer of skin or a piece of paper.
They’re two different things. Think about a 90 mph fastball: it can be stopped by a chain link fence — it’s just too big to get through. But if you get hit by a 90 mph fastball, it’s going to hurt.
Please correct me if I’m wrong here. I’m trying to figure out what this is all about.
As I understand it, if you wear protective gear around materials that emit alpha particles, so that you avoid ingesting or inhaling any radioactive substances that emit alpha particles, and you take precautions to avoid spreading any contaminated dust or liquids out of the area, you’ll be reasonably safe. It’s like standing behind the chain-link fence.
But if you inhale or ingest radioactive dust that emits a high rate of alpha particles, it can collect inside your body and damage the cells that are next to those particles, possibly causing cancer.
Typo: Becquerel discovered radioactivity about 1896, so this was in the 19th century rather than the 18th.
Thanks! I think the editors already picked it up by the time I saw the comment.
IOW, as anyone who already knew anything about radiation already knew, the Japanese reactor issues are political and not radiological problems.
So far.
Political, and psychological…..and whatever happens, they will remain so.
This is very good. As with anything ‘radioactive’ the initial complexity to the ‘consumer’ becomes overwhelming at times. But frequent ‘exposure’ (pardon the pun) and frequent re-familiarity will bring a commonality to both the terminology and the concept of radiation (not to be confused with “radioactive contamination”).
In a universe where these concepts and fundamentals are as common as hydrogen, it’s hard to understand why we aren’t more comfortable with the notion of radiation than we are. But I suppose it has to do with our public “education” system. It’s easier to understand radiation than Public Schools.
Excellent article! We need more rational explanations about Fukushima and fewer breathless histrionic reports from the media.
I’ve always told people that the danger from a nuclear plant is a magnitude less than lying on the beach under a nuclear fusion furnace (aka “The Sun”).
“In the last months of the nineteenth century [...]” Aaaargh.
Thanks very much for an exceptionally well written, cogent article. I’ve passed it on to some colleagues.
Looks very interesting, but I think there’s a typo in “18th century” in the first sentence. Please feel free to delete this comment.
Oh, no, you guys can just keep administering the beatings for the typo.
Minor correction, Curie lived in the 19th and 20th century, the 1867-1934.
I think you mean Becquerel and the Curies made their discoveries in the late 19th century, not the 18th.
Are you trying to tell us Japan is a banana republic?
PS Among Asians a ‘banana; is someone who’s yellow on the outside and white on the inside. It’s not nice to be accused of being a banana.
NO, I am most definitely not saying that.
Troublemaker.
Please allow me to speak up in defense of bananas themselves. (By that I mean the actual fruit, not persons targeted by an ethnic slur.)
Potassium may be a source of natural radiation, but it is also an electrolyte required by the human body. Electrolytes need to be at their proper levels for the body to function properly. If the level of any electrolyte (often sodium) is too high, the body has to do some extra work to get rid of it. If electrolyte(s) are too low, then various cellular and nervous system functions are impaired. The nervous system uses electricity as part of its mechanism for sending messages. A severe lack of electrolytes means flatline.
Sometimes I wonder if the press has any idea how badly they’re stating things when they confuse “µ” and “m”.
Then I wonder if they even care.
Rule #1 – concerning the dinosaur media and environmental activists. If it doesn’t fit the narrative, scientific notation becomes relative.
Meh! Just a bunch of zeros. Noting to be concerned about.
Watching and listening to the MSM’s accounts of Fukushima has led me to conclude that, if the business of terrorists is terrorizing the maximum number of people, the most accomplished terror group in the world is the western MSM. Sorry for the exaggeration, somewhat. I do not mean to minimize the events at Fukushima nor some of the possible failures in response, but the MSM has been a font of sensationalized misinformation.
Thanks for the concise summary, it is an excellent companion piece to the xkdc graphic.
Dn’t apologize, I laughed out loud at the terrorism line.
This was somewhat helpful, given my total lack of background. Am I reading correctly that RAD and REM/Sievert are virtually the same in regards to Fukushima radiation, because the weight factor is 1?
Also, am I understanding that the constant repairing that our bodies do are not taken into consideration, when measuring total dose? (b/c we really aren’t sure how to reliably factor that in?)
My brain got full at that point, so I gave up on the whole banana equivalent thing.
I have a friend in Tokyo. If standing at the Fukushima gate for 15 hours is roughly equivalent to one CT scan, then it sounds as though the radiation risks should not be too great for the population as a whole. Assuming they get the plant under control.
And assuming that there is not some kind of long-term build-up of radiation in the food chain. Which I also have no understanding of. How long does it take for the radiation to dissipate from the environment?
I know, that’s probably another whole can of worms I can only partially digest.
Anyway, thanks for trying to break it down for us.
This was somewhat helpful, given my total lack of background. Am I reading correctly that RAD and REM/Sievert are virtually the same in regards to Fukushima radiation, because the weight factor is 1?
Almost. Rads aren’t much used any more, but they’re really a little bit more than 1 Roentgen, because people absorb a little more radiation than air does. A rem is really the dose you get from a rad, and 1 rem = 1 rad for betas and gammas. But the easiest thing is to just forget Roengens and rads entirely, and use the metric equivalents. Then 1 Sievert is 100 rem by defintion, 1 Gray is 1 Sievert because the weighting factor is 1.
Also, am I understanding that the constant repairing that our bodies do are not taken into consideration, when measuring total dose? (b/c we really aren’t sure how to reliably factor that in?)
Yes, exactly. There really aren’t very good experiments to understand how people react to small doses of radiation because people so object to being given controlled radiation doses for science, so they use a model called the :linear dose response model” which makes two assumptions: radiation dose is cumulative, and if a radiation dose of X causes so many additional health problems, the half of X produces half as many, no matter how big or small X may be. Neither assumption is particularly good, but they’re very conservative. The reality is that our bodies do certainly have some ability to repair radiation damage, so small doses are almost certainly much less harmful, and there’s even some evidence that small doses actually improve your health outlook because once a little extra radiation kicks those repair mechanisms into high gear, they go around and clean up a bunch of other little random damage. (This is called “hormesis” if anyone wants to google it.)
My brain got full at that point, so I gave up on the whole banana equivalent thing.
I sympathize. The main thing is to keep in mind that we always get small amounts of radiation.
I have a friend in Tokyo. If standing at the Fukushima gate for 15 hours is roughly equivalent to one CT scan, then it sounds as though the radiation risks should not be too great for the population as a whole. Assuming they get the plant under control.
Exactly — and while they’re still working on it, it’s pretty much under control now.
And assuming that there is not some kind of long-term build-up of radiation in the food chain. Which I also have no understanding of. How long does it take for the radiation to dissipate from the environment?
It depends on which isotope it is, but most of the radiation release has been radioactive iodine, which has a “half life” of 8 days. What that means is there’s half as much of it left eight days later — the other half has emitted a beta particle and turned into xenon, which is stable. So after eight days there’s half as much, after 16 adys, a quarter as much, and so on. The risk with iodine is that it concentrates in the thyroid, especially in children, which is why they had people giving their babies bottled water in Tokyo for a while.
My goodness that was helpful feedback. Thank you, Charlie Martin!
Here’s the really fun part.
The US nuclear industry, at least in day to day operations, uses REM/Rad, not Seiverts. I gotta go back a ways, now, but I recall the official definition of a REM is 100 ergs per gram of soft body tissue deposited by X or gamma ionizing radiation. The standard unit of dose measurement in the US commercial nuclear power program, and in the US Navy, is the MilliRem (10-3 REM or mREM).
Wait. It gets better. The Army, because they potentially deal with huge doses in connection with nuclear weapon detonations, use the unit Gray, where 1 Gy is equal to 100 Rad, which in soft body tissue for gamma is 100 REM.
I think one of the reasons that the US stays with the REM is clearly illustrated by our frothing at the mouth popular press and it’s inability to deal with numbers in powers of 10. Once you get above having to count on 5 fingers for these folks, the numbers just become magic, and laden with dread; and that’s just when doing their checkbooks. Micro-Seiverts? They are done before they open their mouths.
Yeah — medicine uses Gray and Sieverts, though. I’m an unabashed metric system partisan, though.
“The US nuclear industry, at least in day to day operations, uses REM/Rad, not Seiverts.”
Not to be nit picky, ok maybe I am
…BUT…. the scan that I had on my truck a few months ago was in Seiverts/hr. They used a charged field detector with a mylar alpha particle filter. It was designed to measure Beta and gamma – exclusively.
I was delivering Radioactive components to a Nuc plant. The scan was performed by the shipper.
Actually….it’s the Roentgen that is being abandoned as a term
used. RAD’s and REM’s are not being abandoned.
RAD’s are the amount of energy absorbed…REM’s are that same amount
of energy absorbed by human tissue x the Q factor. For x-ray/gamma
and Beta they are not identical essentially equal….
Typography problem: 1 Curie = 3.7×10¹⁰. Use unicode U+2070 and U+00B9 for the superscript.
yes — <sup> works even better, but it was lost in translation from my original Word doc.
Very nicely done, Charles!!
From an old radiation protection officer, who is amazed at the ignorance in the media about things in general, but especially about this. . . .
Thanks for the lecture. The only frightening thing now is realising how much of physics I’ve forgotten.
Wonderful article. I am a radiologist and I sent this to all of our residents and to our physicist. Thanks
Thank you especially for the chart. A little reality puts the hormonal teenage talking heads in television in perspective.
It’s hard for me to follow all these changes in measurement. Do I have this right?
As a baseline:
- Normal background radiation = 3.36 rem/year
- Increased cancer risk = 100 rem/year
- Mammogram = 3 rem/instance
At the Fukushima plant:
- Currently = 175 rem/year
- At worst by the main gate = 876 rem/year
- At worst, outside hot spots = 14 rem/hour
- At worst, inside hot spots = 40 rem/hour
- Increased cancer risk = 100 rem/year
- Mild radiation sickness = 400 rem/(a short time)
- Possible death = 2000 rem/(a short time)
- Likely death = 4000 rem/(a short time)
- Certain death = 8,000 rem/(a short time)
So we could have been inside a reactor building for 2 of its most radioactive hours and still not have any proved increased risk of cancer? Same if we go live and work at the gate for 6 months today? And this, after a 9.0 earthquake and tidal wave, causes Charles Krauthammer to say the US nuclear power industry is dead?
Well, close. I think you’ve got everything up by a factor of 100. Let me check back over the copy, I think a typo crept in there.
That’s a good suggestion for a table though, I’ll add one.
Everything by 100? That can’t be correct for “everything”. Can you please correct it. I’d love to post it elsewhere, with a link back to this article of course.
Can someone point me in a direction which gives a scientific counterpoint to the claims of John Goffman?
Your mixing of units is VERY confusing. Let’s see
1 rem = 10 mSv (?)
A CT scan gives you 13-15 mSv (?)
The Fukushima dose rate is 20 microrems/hr, although you say that on March 19th it was 0.1rem/hr or 100000microrems/hr (?)
20 microrems/hr, over a year, would be 175200 microrems or 175.2 mrem? You say 1762? A CT scan gives you 13-15 mSv, or 1.3-1.5 rems, or 1300-1500 mrems? So a yearly dose of current Fukushima is about 1/8 of a CT scan?
Similar conclusion, but maybe less confusion?
Your mixing of units is VERY confusing.
Indeed!
Charlie, you jumped around too much. Tables are a GOOD thing!
Aren’t you off by a factor of 10 in your BED calculation?
(1 micro Sv = 100 micro rem)
Check your conversion between Sv and Rem in the final paragraphs. There seem to be a factor of 10 between them … I remember it as 100 Rems per Sievert. Otherwise thanks for this and all of your other posts on the subject. The more of this the better. Best thing I can think of off hand for the masses would a be a simple table listing the dosages that cause death, sickness, detectable increase in cancer rate, …
down to dental x-rays and bananas.
Go to this link to find what you’re looking for.
http://xkcd.com/radiation/
I’d be happy if the media would stop saying “radiation” when they mean “fallout”. I don’t know how many times I read about the “radiation reaching the west coast”.
1 mSv equals .001 REM (radiation equivalent mammal). .10 REM would be an enormous dose of whole body radiation in “radiation safety” terms but still far from a fatal dose. Also the quality factor does not tell the whole story particulaly wrt electron radiation. Beta radiation exposure typically results in far less whole body dosage because the electons typically emitted by decaying radionuclides do not have enough energy to penetrate deeply into the body.
You really should have had an expert review your essay! There may be other errors but I stopped reading at the above boner.
Well, no, 1 mSv = 0.1 rem. Maybe you should have had an expert review your comment.
Oh, I know I shouldn’t snark at the commenters, but really.
I think Charlie kept it simple and clear for the layman without unnecessary detail.
Sure, there is a difference in the energy of particles or radiation. For example, iodine-125 is a low energy gamma emitter, the radiation just doesn’t extend very far. It is very safe to work with. Iodine-131 however, is a high energy beta emitter, and you do your best to limit your exposure to it.
Then there is the additional topic of radiation impinging on or passing through the body versus a radioactive substance being absorbed into the body, quite a different situation. That would be too much detail for this article, I think he got the scope of it right.
Although I 125 emits a low KeV gamma, it also has a long half life. While the low energy does mean that it has little penetration (range in tissue) as an EXTERNAL source of exposure, you have to change your perspective when dealing with INTERNALISED activity due to the residence time in tissue. In fact, Iodine 125 has been successfully used for treatment of metastatic neuroblastoma , despite its “low energy”. How can it get internalised? Iodine of any radioisotope can convert to Iodine -2 gas which when inhaled is concentrated in the thyroid. Iodine in foodstuffs is orally absorbed from stomach and again concentrates in thyroid. As an aside, in all of the (exaggerated) discussions about the risk in Japan, keep in mind the distinction between external exposure and internal contamination.
18 months ago, my thyroid scan was done with I-131.
I’ve taught this material in both the military and commercial nuclear programs for many years now and, I’ve gotta say, this is one of the best summaries I’ve read. This is readable and understandable in a way the modern education and press organizations haven’t even tried to match. Nicely done.
The 4th biggest earthquake in recorded history. A Tsunami twice as large as the worst the cautious Japanese planned for (destructive power might be more than 2x). 15,000 people dead and counting. Unbelievable courage and stoicism by the Japanese people. One guy even scrounged scuba gear to rescue his wife and mother shortly before they would have perished in their flooded town.
Not a single death attributed to the nuclear accident. Nobody yet known to even be sick from it.
Yet a nuclear catastophe is 95% of what we hear about.
Lucky for us the Make Believe Media has no agenda, isn’t it?
exactly
one of the largest earthquakes and one of the more destructive tsunami’s
will cost $300-400 billion to “fix”
our economy, on the other hand, will cost roughly 30 more times than this
(if we attack it now)…. oops… add in another billion or so as i write this…
now what happens if we learn that these tidbits of radiation that are leaking may actually fight cancer in people that didnt even know they had the disease?
it’s good to get some empirical insight but we all know the lefties dont fuss over facts
It’s to the point that I almost believe that it is deliberate. A kind of “Hey, lets give people something else to focus on other than the 20,000 dead and 200,000 homeless.”
Not a single death attributed to the nuclear accident.
You don’t understand. The nuclear accident is not over. Tell me in two years the relative proportions.
I have a perfectly good understanding of it.
About 20,000 deaths have recieved 1/20,000th of the attention.
It isn’t about Japan’s tragic natural events, the destruction they caused, and Japan’s heroic response to them; it’s about the left’s lunatic agenda to strangle energy from the US and the world.
If you can’t see that, then YOU are the blind one.
Is there a decimal off in the last paragraph?
IIUC, 2 microseiverts/hour should equal 200 microrem/hour not 20. That would make it 1/100 the rate the legacy media is reporting, not 1/1000.
I hate decimal points.
Charlie, like you I am a metric fan.
But, one day I was enthusiastically waxing about the metric system to an engineer friend. He really dampened my enthusiasm when he pointed out that the metric system is very susceptible to “magnitude of scale” (i.e. decimal point) errors. When he said that my mind immediately recalled the fatal nuclear medicine poisonings that occasionally occur when lab techs forget the difference between micro- and milli- rems.
Nothing is easy, is it?
As a former navy reactor operator, NRC licensed senior reactor operator, certified rad tech and nuclear startup engineer, let me interpret the media’s reporting.
We have the hype that the Japanese #3 reactor is fueled with evil Plutonium 239, which fissions and produces the chain reaction to heat water in the core. But what most don’t know is that the standard Uranium 238 fueled reactors actually “burn” Plutonium 239 since Uranium 238 is not fissionable. The Uranium 238 absorbs a neutron from an installed neutron source and small amount of U-235 fissioning, the neutrons converts U-238 to Plutonium 239, which is fissionable. Plutonium 239 is a heavy metal and an alpha emitter in its radioactive decay. It is only a serious danger if ingested or breathed, since an alpha cannot penetrate one’s skin or even a piece of writing paper. The real concern is that all of the reactors’ cores have fission products trapped inside the fuel rods after fission. They are the radioactive hazard and regardless of which reactor core has “melted down”; some are chemically the same as nutrients needed for plants such as radioactive Cesium 137 (acts like potassium) and Strontioum-90 (acts like calcium); so they enter the food chain and are the major concern in milk. PU-239 is not recognized as a chemical needed by plants, so it does not enter the food chain.
BWR’s produce steam in the vessel/core and the steam is directly piped to the turbine generator with inline isolation valves. Thus the steam piping penetrates the reactor vessel (primary containment) and the secondary containment (drywell) on its way to the turbine. A steel structure (rectangular building in the pictures) covers the main portion of the complex to contain the slightly radioactive steam going to the turbine. No water put into the reactor is entirely pure so there is some activation of that extremely small amount of impurities as the same with the fuel cladding impurities. Anyway there have been reported hydrogen explosions destroying the steel building, radioactive Iodine-131, and some radioactive contamination, probably fission products. That tells me one or more of the cores are open to atmosphere and have been for some time.
Also the tsunami apparently destroyed the emergency diesel fuel storage tanks, preventing the emergency power to be supplied to the emergency cooling systems’ pumps. Otherwise these units most likely would have been shutdown properly. Such an event is beyond most people’s and engineers’ comprehension. Oh, Diablo Canyon has become a focus of the media lately because it is on a fault line. Information I have is it is 85 ft above sea level. If a tsunami is that high, the people of CA will have more to worry about than the reactors.
I wish FNC and the rest of the media would interview those who have been there, done that, rather than former the senior management of the NRC and the like. Maybe then they would publicize some information based on facts.
One thing that strikes me is that a 1000 year quake followed by a 1000 year tsunami a half-hour later is probably a 50,000 year event. (Not 1,000,000 year as it would be if they were completely independent, but you could certainly have had a force 9 quake in that area without a major tsunami too.)
And you just can’t design around every possible 50Kyear event. That’s probably in the same order of magnitude as a major asteroid strike. (“What’cha gonna do/when it falls on you?”)
Well that is true to some extent. But you also need to balance risk.
i.e. when your coal plant goes tits up you will not need to declare a 50 mile exclusion zone and monitor the food and water for 50 or 100 years.
You can’t design against all low probability events. What you can do is localize the damage. With some designs.
Anyway there have been reported hydrogen explosions destroying the steel building, radioactive Iodine-131, and some radioactive contamination, probably fission products. That tells me one or more of the cores are open to atmosphere and have been for some time.
That is my take and I have been reporting it that way for some time. (since I heard about I131)
More problematic is the reports of I134:
http://powerandcontrol.blogspot.com/2011/03/worst-case-scenario.html
is the radiation spewing out of japan affecting my eyesight or is there a problem with the fonts?
Gak! Look at comment 30 ^^^^^!
And the word “spew should be banned from the internet, too.
i guess my attempt at facetiousness failed
Sorry Charlie my mistake. But it really irritated me when ‘they’ decided to replace the perfectly usable RAD with Gray (equal 100 RAD) for no apparent reason.
No worries. I think the thing about rad was that the difference between ionization created (Roentgen) and energy absorbed (rad) puts in this weird fudge factor of 0.93 (and change) that was terrifically inconvenient. On the other hand, Gray and Sieverts seem inconveniently large. What are you gonna do?
SI units: 1 Gray = 1 Joule/kilogram.
Spotted in the Health Physics journal many years ago…
And it has the side-effect of reminding me that Sievert corresponds to rem, which leaves Gray to correspond to rad.
As we are measuring a bit of radiation in the states, this radiation is emitted from fallout particles. There are several different types of particle, emitting various levels of radiation.
So… what is a minimum particle size of for example, Plutonium…one molecule..and how much energy can we it expect to shed during it’s rather lengthy active stages, and what is it’s relative value in Micro sieverts.. what is the threshold of rad, rem measurable health effects over a lifespan.. what is the makeup of the particles, their collective energy levels, their practical overall impact..
My point being that it is likely that we shall ingest or inhale these particles.. where they will sit and emit practically forever…some of them..
A lot of questions remain which would clarify further our current and STILL ongoing situation..
But thanks very much for writing this common sense article which I will read a couple more times until I manage to soak it up a bit better… it is a great help.
Possibly you might speculate a bit on the fallout values I refered to..
Mark, when we get down to single atoms, say of plutonium, then things get complicated. First of all, plutonium has a very long half-life, 79 million years, which means the odds are only 50-50 that it will have decayed in that long. That makes it 3-1 in 158 million years, 7-1 in 237 million years, and so on. So if you were to pick up a single atom of plutonium, you would never notice — it’s very unlikely to decay in your lifetime, and if it did, you’d pick up one count’em one alpha from it. You get lots more than that today.
But a reasonably-sized particle is lots more than 1 atom; a gram of plutonium has a radioactivity of 690,000 Bq. So a banana equivalent in plutonium is about 20/690,000 g or , let’s say, about a half a grain of fine beach sand.
HOWEVER plutonium isn’t what’s been released.
The oxide of plutonium — which is the form it almost always found in — is basically insoluble in water, i.e. approx 10e-6 by weight. You’d have to ingest a lot of plutonium to get any kind of radiation hazard: 1 part in 100,000 ingested is retained. The combination of long half life, low solubility, and absent biological path means plutonium is not a potent radiological threat. All of the concerns about plutonium revolve upon breathing “small particles” (<5 microns) of the oxide somehow distributed as a dust after a fire. Even then, only 1% of such particles are retained.
Compared to (say) ordinary (non radioactive) mercury oxide, plutonium oxide is harmless. Mercury oxide is poisonous, carcinogenic, mutagenic and *never* gets better no matter ow long you wait. Yet no one talks about guarding mercury waste for an eternity.
It's always amused me that the fact that the fact that radiological poisons decay overtime is held against them. There are megatons of nasty poisons buried every year that will remain poisonous forever. Nobody talks about guarding them for generations. Toxic waste disposal is difficult, but the radiological component of the problem is very very small.
I thought inhaling bananas went out with the 60s. Passing through the gut (with some incorporation) is different from total incorporation in the lungs.
And Charlie: they are now going out and looking for plutonium:
http://powerandcontrol.blogspot.com/2011/03/tests-have-been-ordered.html
I interpret this to mean that they actually know and will soon be making announcements. If they know the status of I131, they know the status of Pu.
I’m sorry to say that what is going on will kill the nuke industry as we know it. Faster because of the cover-up. And what better culture for cover-ups than a face saving culture? Which is to say – we are screwed, blewed, and tattooed. But it was a heck of a party while it lasted.
Oh, don’t be a dolt, Simon. Do you think a banana goes through the gut unchanged? Of course the K-40 is absorbed.And yeah, and Pu inhaled is different than K-40 absorbed, but (as I noted below) the toxicity and carcinogenicity of Pu has been way overblown.
Charlie, here’s a big part of the problem:
http://www.bbc.co.uk/news/world-asia-pacific-12872707
The problem is putting this kind of headline into perspective. 10,000,000 times “usual” doesn’t mean much, without knowing what “usual” means. And it’s not even clear what “at reactor 2″ means.
People read this stuff, not realizing how imprecise all of the language is, or even that it is imprecise. They think that verbal vomit actually means something precise.
Oh, 10 million times would be scary. It also was just incorrect. http://www.foxnews.com/world/2011/03/27/workers-grapple-radioactive-water-troubled-japan-nuclear-plant/
Oddly, BBC hasn’t corrected their article yet.
That’s the other thing – if it sounds ridiculous, it’s probably wrong.
But the other point is, what is “usual”? The water circulating through the reactor? The water running down the sewer? Even if it were true, there’s not enough information there to make sense of what it actually means.
Regular reports in the last 12 hours say some where in the area of the reactors the dose rate is 1 Sv per hour.
Charlie: note the pattern:
1. something alarming is reported
2. it is discounted
3. within days (sometimes hours) something more alarming than the previous alarm is reported
4. it is discounted
5. the discounted report is worse that the previous discount
Which is to say watch the direction (trend). Things are getting worse. And the honest folk from TEPCO (PETCO?) will not let any independent agencies monitor the radiation levels in the area of the plants. There will only be one source of information on plant status (unless you can read between the lines). Pravda.
Keep looking at the real data. That 1 Sv/h is in the water. The “victims” just got sent home, because their 2 Sv+ exposure was too little to create burns.
Why?
Beta.
Actually IIRC there were a bunch of over the hill physicists serving on an advisory board with a lot of time on their hands who wanted to honor a couple of guys named Gray and Sievert. The rest is history. By the time I learned radiation physics the Roentgen (exposure dose or “R”) was already totally yesterday! What counts in terms of carcinogenesis or cell kill is the absorbed dose (Rad is actually defined in terms of energy/gram IIRC and is “small” in terms of every day energy magnitudes…I am thinking 100 ergs/gram but it has been awhile!) at the cellular level and that was different conceptually. But there was no change in concept or methodology in replacing RAD with Gray. (End of old fart lecture!)
“the last months of the 18th century” should read “the last years of the 19th century”
“19th” century it is now; as far as “last months”, yeah whatever.
Good summary. Ramsar is in Iran, however, not India.
No,, Rajasthan, west of Delhi.
http://maps.google.com/maps?hl=en&safe=off&q=Ramsar,+Bikaner,+Rajasthan,+India&ie=UTF8&geocode=FUBHqQEd-L1iBA&split=0&sll=26.282505,74.87849&sspn=0.012348,0.011096&hq=&hnear=Ramsar,+Bikaner,+Rajasthan,+India&ll=27.858504,73.586426&spn=16.779476,21.313477&t=h&z=6
There is an area with real high background dose-rate in Iran too.
Charlie, tinyurl.com is your friend!
Well, there are two Ramsars then, but the high radiation one is in Iran. See here, for example: http://www.angelfire.com/mo/radioadaptive/ramsar.html
I wonder why Dr. John (usually listed as “A physicist”) from Charlie’s many Tatler posts hasn’t shown up here yet.
Any theories, Charlie?
Remember the lesson of Beetlejuice.
I have admonished folks with whom I work, that now is the time to be meticulous to the extreme with units. I’ve seen at least three (probably more) errors in reporting.
One was mistaking Bq/cm^3 for Bq/m^3. A factor of a million– something where activity is concentrated in a volume the size of your pinky tip to one where activity is diluted in a volume the size of a freezer.
Another was a crawl on FNC that the “hazard” from I-131 would be gone in eight days. Saw that one today. Also something about radiation being 10^7 times “normal.” Looking over my shoulder at FNC… Someone’s apologizing for that one.
Another was a local radio (770 KKOB in Albuquerque, NM, USA) talk show host, saying that the “Fukushima Fifty,” the guys doing shifts to maintain the plants in as safe a mode as possible are “dead.” Not true. They’ll accumulate “emergency” doses to save lives and equipment, but I’ll bet (real money) that they aren’t dead and won’t die from effects of their efforts indistinguishable from what is natural.
Meanwhile, ~26,000 are dead or missing there. From kinetic actions of dirt and water.
Yeah. The FNC report is excusable; that was reported by TEPCO, then corrected; someone made a mistake with the instruments. The units thing is just driving me nuts, although to a first approximation, the source for every hair-on-fire news story has turned out to be someone confusing micro- for milli- or something equally silly — or the story was based on a doomsday prediction from someone connected to an anti-nuke group.
The actual reports are that something under 20 people have received doses > 100 mSv (10 rem) and the highest doses were the same guys who got their feet burned, with whole-body doses of around 170 mSv (17 rem).
Those doses may have an increased lifetime cancer rate, but otherwise have no health effects. Including not dying.
What affect would there be on a number of fuel rods that were under 5.5 mi. of water? The subduction process is slow but the water pressure might have containment properties and effectively act as a storage area.
Not much — 5.5m is only 18 feet. The cooling, and direct shielding effect, are far more important.
Hello Charlie, the person was talking about miles and subduction.
IOW, what happens when you dump the stuff to the bottom of the ocean at the subduction zone. This is a question that needs serious study.
I believe it was very cursorily studied during the early stages of certifying WIPP. My impression is that it’s actually a really good idea done right; meaning, put the waste in a torpedo case, so it penetrates the muck at the bottom. Muck is a great adsorbent for any waste that leaks.
But there are two fatal flaws with the plan. One, there’s no way to retrieve the waste in a hundred years for its valuable radionuclides. Which I’m convinced our descendants will want to do with the waste we’re now refusing to reprocess.
And, two, it’s an unambiguous violation of international law to dump radioactive waste at sea, no matter how much sense it makes technically.
In this particular instance, where we have tons of radioactive junk at an ocean beach, it makes technical sense to build some robotic vehicles and cranes, put everything on some barges, and scuttle them. I don’t think entombment on site is such a great idea in such a densly populated country.
The only alternative that I see is ask Mr.Putin what his price would be for landfilling it all somewhere in Kamchatka.
On the subject of units, have you seen this?
http://motls.blogspot.com/2011/03/radioactivity-sieverts-and-other-units.html
Thanks. His physics is good, his biology kinda sucks, and he’s got some issues with the details,
That chart you linked to Charlie is fascinating. I actually found a perusal of that more helpful than all the network news and “experts” I’ve listened to in the last two weeks.
I think I’ll invest in all “wood” houses and market it under “low radiation dosage” homes, due to the dangers of brick and stone.
For those interested bravenewclimate.com is providing a lot of good data from the science based standpoint. The nuclear issue in Japan is very serious, but has been so overblown by the MSM it is pathetic. We should be focusing on the earthquake and tsunami damage.
At the same time, I know the Navy itself is very concerned with the doses received by their people. I personally feel that finally TEPCO is getting a handle on the situation that there will not be excursions. For two weeks it has been “what disaster will tomorrow bring.”, soon that should end.
That’s a good source. It answered a question that I couldn’t get an answer to anywhere else: what’s the problem with the salt. The answer is that they were putting sea water in, but not draining the concentrated brine anywhere, so it was concentrating and concentrating.
It all makes a lot more sense when you know that.
The depth at the Japanese portion of the Marianas Trench is five and one half miles. It is approx. 100 miles east of Sendai. If the corrupted artifacts from the reactors were dropped on the Pacific Plate next to the subduction zone the conveyor process could solve a problem or two. The question would be what life would there be at the subduction zone. I know there is Sulphur(?) based life at the ridges, but haven’t heard anything about the trenches.
one other factor, the pressure at 5.5 miles is 12919.1 psi.
Sorry, I reasd “5.5 mi” as “meters”. The pools happen to be 5+ meters deep.
With over 10,000 dead, and 16,000 missing (last estimate I saw) from the effects of the quake, I’d say the nuclear power thing is a minor side issue.
Charlie,
Uh. You do have to worry about neutrons (at least locally) because the sludge at the bottom of the reactors (or possibly a spent rod pool) has gone critical.
53. Dave Surls,
You are only considering the current situation. It is not over. It could go on for months or years according to the Japanese.
Simon, the i-134 was an error — that’s the erroneous report they corrected: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110327e15.pdf
It is my understanding that it is the amount of I134 that has been corrected not the presence.
At this point in time any amount of I134 indicates a nuclear reaction.
What I have noticed is they have a very sophisticated method of lying by omission. They will release isolated facts that tell the knowledgeable what is happening and leave the ignorant in the dark.
Any amount of I134 detected at this time indicates a runaway reaction.
Remember – in Japan it is not lying. It is saving face.
BTW I couldn’t read the pdf.
Read the things I link, dammit. The AMOUNT of I0134 has been corrected — to “undetectable”.
Yeah yeah, them slanty-eyed bastards. I am really tired of hearing about how the Japanese will lie to save face. Among other things, getting caught lying is a much bigger loss of “face”.
In the mean time, they went public with a really scary estimate, then revised it after retesting. Caught hell for that. Then today, they caught hell because they weren’t releasing information quickly enough.
They said “we had two isotopes that showed up spuriously” and published a new analysis that showed them not there. Now people think they’re lying.
I mean come on guys.
As for the PDF, Simon, it opens for me, in Chrome on a goofy development 64 bit ubuntu system.
What I have noticed is they have a very sophisticated method of lying by omission.
As opposed to the MSM’s very crude method of lying by omission?
Despite the fact that people are going nutziod over all of this, this does seem like a clusterfrak. Where’s the Red Adair of the nuclear industry? Could it be that the industry has been too safe, and there’s no money in emergency management?
I will quote:
“Japan’s Nuclear and Industrial Safety Agency said that water seeping out of the No. 2 reactor building into the adjacent turbine building contained levels of radioactive iodine 134 that were about 10 million times the level normally found in water used inside nuclear power plants.”, Inquirer.net reports.
“Late Sunday night, however, the operator of the stricken plant said that the high reading may have been a mistake.” the report added.
Read more: http://www.digitaljournal.com/article/305120#ixzz1HuhaLnoa
So Charlie: the HIGH reading is a mistake. Fine. Any reading is an indication of an uncontrolled nuclear reaction. See the math here:
http://powerandcontrol.blogspot.com/2011/03/worst-case-scenario.html
TEPCO is blowing smoke. This will be very bad for nuke power.
Sorta depends on how you define “uncontrolled nuclear reaction”, doesn’t it?
Oh, and btw – from WORM:
http://wormme.com/2011/03/28/big-media-fukushima-roundup-american-edition/
Dare I say an uncontrolled nuclear reaction?
Simon — M? — so far what appears to be worst for nuclear power is people not reading the actual reports, and depending on a poor translation of a poor transcription of a reporter’s impression of what he thought someone said. Take the I-134 thing: after they redid the test, it was no longer detectable. So yeah, it’s been revised downward. To no longer there.
Take the reports of 1 Sv/h dose rates — those are being reported but people are not noticing that they are dose rates *in* the water, and apparently beta doses. Over at “Worlds Only Rational Man” we actually did the figures, and 1 Sv/h is completely consistent with the measured composition of the water.
The other evidence is that they just sent the wet socks guys home — no beta burns, exposure revised downward to 1-3 Sv.
To quote NHK:
Now, ask the next question — if they received 1-3 Sv, why are they sending them home when prompt treatment could save them significant suffering, 300 rem being a dose that will make life unpleasant? Because it was 1-3 Sv beta from the wet feet. The same report says they received a very small whole body dose. 1 Sv of beta doesn’t even cause beta burns and that’s what they’re observing.
The point is that inferences based on the horror reports on Drudge are depending on information that simply wasn’t true — and it’s not just TEPCO reporting these revisions, but NISA and METI, and the IAEA.
If you’re concerned about the effect on nuclear power, then don’t run around with burning hair without keeping up on the data.
some areas around reactor will be uninhabitable for decades:
http://www.mext.go.jp/component/english/__icsFiles/afieldfile/2011/03/27/1304097_2713.pdf
163 000 bq/m3 of Cs137
which means 150 millisieverts per year- http://news.sciencemag.org/scienceinsider/2011/03/japan-soil-measurements-surprisingly.html?rss=1&utm_source=twitterfeed&utm_medium=twitter “This is well above the U.S. Environmental Protection Agency standard of 50 millisieverts per year for an evacuation”.
half life of Cs137 is 30 years.
How long were Hiroshima and Nagasaki uninhabited?
how high was Cs137 contamination level there? and why do you always have to ask the stupidest question possible? is it for sport?
Well, to be perfectly honest, watching somebody running in the streets at night with his pajama tops and no bottoms screaming “the end is nigh” does bring out my inner troll.
LOL.
That was a good one.
A friend of my father’s was with the first U.S. unit to go to Hiroshima. He used to complain bitterly about the Army allowing them to wander around the blast area, with no warnings about possible health risks. Apparently he and quite a few other GIs spent quite a bit of time there, and he was sure he was going to die of cancer.
He did have a few skin tumors cut off over the years. He passed away a few years ago from heart problems, in his mid 80s.
Ne never did have children. I suppose it’s possible that was the result of radiation exposure.
Perspective is a good thing.
and now they are detecting plutonium:
http://english.kyodonews.jp/news/2011/03/81609.html
let’s hope it’s another mistake?
Pu on the edge of detectability. http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110328e14.pdf Two sites give Pu-238 at a little above what’s considered normal variation for garden dirt in Japan; the isotope ratio is the only hint it’s from the reactors.
Seriously, we have got to stop reacting to Kyodo’s reports — they aren’t seeming to ever quite match up with the real reports.
Another example is the report of the wet socks guys taking 1-3 Sv — but having only a very low whole-body dose and being sent home with a “clean bill of health”. But 1-3 Sv is anything from a little bit sick to pretty damn sick — if it’s a whole-body dose.
This only makes sense if they’re talking about 1-3 Sv over two hours in the form of beta, and sure enough when you actually look at the actual reports, they’re saying they see dose rates of > 1 Sv/h in the water.
it’s not about how much, it’s about how the hell did it get there?
and how did Cl38 get into water of unit 1?
Didn’t. That’s one of the things that went away when they retested.
People are having a hard time getting the hang of this “don’t trust it until it’s been verified twice” thing. Now I understand why Alex Jones and WND have so many readers. Certainty is comforting, even when it’s wrong.
Well, in that peculiar sense of “comforting” in which people perversely want everything to be going to hell.
i missed this part – any links?
TEPCO published data with the mea culpa about the error here: http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110327e15.pdf
The four columns are the error data, the retest of the original, and then new data. On the I-134 line, there’s a value given for I-134 in the error column, and “not detectable” in the rest.
charlie, are you tired, man? i am talking about Cl-38 in unit 1, your link is about unit 2 specifically.
BTW, just wrapping around to the article, the “banana equivalent activity” of the detected Pu is 0.004 — a kilogram of bananas has 241 times as much activity.
IAIE saying: “Japanese authorities today confirmed finding traces of plutonium that most likely resulted from the nuclear accident there…the isotopic composition of the plutonium found at Fukushima Daiichi suggests the material came from the reactor site, according to TEPCO officials. Still, the quantity of plutonium found does not exceed background levels”.
how did it get there, pollyanna chorus?
The same way the background level got there?
Poul, have a look at the bottom of the column, and at the total values. There is detectable Pu in the soil any time, and pretty much everywhere, because of above-ground testing in the old days. Plus, someone set off both a uranium and a plutonium bomb in Japan not quite a half-life ago. The amounts of activity shown are truly minuscule — as I said 0.004 times a kilo of bananas.
Pu-238 has a specific activity of around 634 GBq/g according to Wolfram Alpha — which means they’re detecting about 9×10^-13 grams, or only about something like only 1 billion atoms of Pu per kilogram of soil
charlie, the point you’re ignoring is that “the isotopic composition of the plutonium found at Fukushima Daiichi suggests the material came from the reactor site, according to TEPCO officials”, not the one found naturally – and probably not with the one that could remain from underexploded nuclear bomb…
so again – any ideas how did it get there?
For Joebody:
A constant-run C/T scan is not exactly a useful analogy because of the half-lives of the radioactive elements and the distance of the general public from the sources of radiation.
Radioactive dust will decay just like evertyhing else. While I’ve not done any calculations, it seems to me the “dust” would have to be a not insubstantial amount a highly radioactive heavy elements; the kind of stuff which is the reason for the containment structure. I don’t think you’d get much uranium or plutonium fallingf out of the sky as rain, or getting into the sky as dust.
Prompt neutrons come from fission. Delayed neutrons do not.
A broken fuel pin may release one or more or pieces of fuel pellets.
How likely is it that these pieces have fallen into an array that makes a self sustaining chain reaction in the Cl- and Borated water solution, not to mention proper spacing for moderation of the prompt neutrons?
Or is it more likely that the neutrons we are seeing are delayed neutrons that are being emitted by fission product decay?
Hint: Use Occam’s Razor.
Prompt neutrons come from fission. Delayed neutrons do not.
A broken fuel pin may release one or more or pieces of fuel pellets.
How likely is it that these pieces have fallen into an array that makes a self sustaining chain reaction in the Cl- and Borated water solution, not to mention proper spacing for moderation of the prompt neutrons?
Or is it more likely that the neutrons we are seeing are delayed neutrons that are being emitted by fission product decay?
Hint: Use Occam’s Razor.
Fuel disposal. Japan reprocesses fuel. No need to drop it into the ocean.
Maybe we could ship it to Hanford.
Please. I want to watch all the Portland moonbats melt down.
Reprocessing is the easy part. The hard part will be dismantling and repackaging. That’s going to take equipment that we may not have yet.
“Fuel disposal. Japan reprocesses fuel. No need to drop it into the ocean.”
Fine. If nothing needs be done then the point is moot. It was proffered as a question initially with further action taken if called for. As a boilerman on a 600 lb. main propulsion system I was aware that at higher pressures the properties of water acted differently than expected (say @ 1200 psi heat flow was messed up and pumps had to be used.) My question was, with no heat applied but at immense pressures would the properties of water be adequate to act as a natural containment for corrupted material (not suitable for reprocessing?)
The high (static) pressure means nothing’s going to boil. And that’s about all it means.
Okay, I’m a looong way from being a nuke expert, but I did stay at a Holiday Inn once.
Well, actually, I worked as a steam jumper at SONGS (Unit 1) when they were trying to sleeve the steam generators to extend their useful life. (Hey, I was out of work and needed money. Minimum wage x 12 hour shifts x 7 days per week to sit around and wait? Not bad when you are out of work!)
We went through a few days of training on nuke safety, then training on the tasks we would perform, then did a lot of waiting, some working, and finally we’d burn out and be off to whatever was next.
Anyway, the biggest danger, as I understood it, was not the radiation, but particulate contamination. We were told the only treatment was “immediate high amputation”. As in, contaminate your finger and lose your arm, not now, but RIGHT NOW.
It was real fun when I sat down to rest a moment, and my butt got wet. When I sort of mentioned that my suit was breached it was interesting to see how fast everything went from ho-hum to FULL EMERGENCY mode. Lots of yelling at me to GET OUT OF THERE!!! and people rushing me to The Coffin to have a scan.
Dunno what they would have done if I had picked up a particle or two, but the scan was clean. =:O
Anyway, I said all that to say all this:
I haven’t seen much discussion of this issue. Charlie, what’s the scoop? Any relevance to this situation?
well, the old story about “immediate high amputation” was always a canard. In fact, the earliest example of it I’ve found was in Heinlein’s story “The Long Watch”, although Heinlein implicitly cites experience at the Manhattan project — which I’ve never tracked down. (Hmmm, sounds like a job for the Heinlein Journal.)
Wikipedia cites a number of studies which showed Pu not to have either particularly high toxicity or to be all that effective at producing cancer:
So, at San Onofre Nuclear Generating Station, in the 80′s, during the experimental sleeving project, they had surgeons on 24 hour standby (yes, they did) based on an old wive’s tale????
This wasn’t workyard scuttlebutt – this was part of our formal training, and we saw the operating room. I saw the surgeon when I had my scan.
And all this based on a tale from Robert Heinlein?
I’m having a bit of cognitive dissonance here!
I should add that I don’t have any trouble believing that the majority of what the press reports is garbled at best, especially when it comes to complex technical or scientific issues. I take that as a given.
And I fully recognize that there are Chicken Littles out there who scream bloody murder at anything and everything that might possibly maybe someday have some possible adverse health effect if you do enough of it long enough. (Some from ignorance, some from a deeper agenda.) I see plenty of it in my own field! (Electromagnetic radiation – the cellphones are making our children into monsters! =:O )
But I’m having trouble processing people in the INDUSTRY spending large gobs of money and effort to guard against a bogeyman no more substantial than the risk of power lines over the chicken coop!
Wow, people are still commenting here?
Mark, I don’t know. I just know I can’t find any source for the “high amputation” thing in medical literature or in Google. It also doesn’t make a lot of physiological sense — your whole blood volume circulates about once a minute normally — say 70-80 heart beats. So you’ve got at most a few heart beats before any contamination would be out of the limb anyway.
here’s the specific quote:
http://www.tepco.co.jp/en/press/corp-com/release/betu11_e/images/110328e14.pdf
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.”
What does it matter, if they said it wasn’t then the burning-hair brigade would just say they were lying.
Look, it’s a reasonable conservative position to take.It’s also one sample out of five, and a lousy half a becquerel activity — at a guess, two sigmas above the average detected from leftover Tsar Bomba fallout. Look at what the IAEA said about it:
So yeah, it’s plutonium, and yeah is seems it might have come from the reactor, but yeah it’s still a biologically insignificant amount, and yeah, we do suspect that someone might have had some reactor problems in the immediate vicinity.
Let me see if I can translate that from alarmistese to English. The existence of minuscule quantities of Pu of the isotopic profile that indicates that it came from a reactor is proof that at least one fuel rod breached!!!
Like a lot of this, it’s Captain Obvious. We wouldn’t be getting any of this stuff if there wasn’t some damage somewhere. But what got out into the air is almost certainly from the pools, and not the reactors. #3 is looking particularly guilty.
This is all rapidly becoming moot, as we’re 18 days into this, and anything spectacular that was going to happen has already happened. Cooling isn’t that difficult any more, as each core is down to less than a megawatt heat output at this point. At this point, there’s just a hell of a mess to clean up.
Yeah, I know. I just invited the panic brigade.
Sheesh!
After reading the article and the comments about mistakes and typos, my mind is reeling about Rads, Rotgens, Milli’s and Micros, I am going to get up, put down my coffe, peel a bananna and go stick my head in a Microwave oven.
Charlie Martin, can you please correct my numbers in the table in post #25? They look fine to me, and there are some people freaking out on Hot Air that really need to see them.
I’ll do a post in Tatler today with updates and corrections; may take until this evening though.
Hi Charlie,
I haven’t been able to find that update. Are you able to correct the figures that you said are off by a factor of 100 in #25? If not, please just tell me. and I’ll look elsewhere. Thanks.
Some thoughts on how long Japan may be down for the count.
http://goldandsilverlinings.com/?p=410
Charlie,
I’m disappointed that you couldn’t be bothered to correct your own work, much less what you suggested were faults in my interpretation of it. This article had potential, but you squandered it by blowing off multiple people who found fault. Why bother writing if you can’t be burdened with quality control? You just end up as another untrustworthy voice in the media that you rail against. I can’t use the information here now because you can’t be trusted.