Mud in Fukushima

Dear Reader,

It has come to my attention that mud at the bottom of swimming pools at Fukushima has been found to contain cesium. A film has appeared on another blog which claims to be a reading of the work of a Masakazu Honda. In this film and the text it points out that the mud at the bottom contains lots of cesium while the film suggests that nothing was noted when the water was tested.

This is perfectly reasonable in terms of chemistry, I have been saying since the accident occurred that the cesium will stick to soil minerals. I would say that it is important to consider both the water in the pools and the mud at the bottom. I think that the best thing might be to use a swimming pool vacuum cleaner to suck out the mud. The mud will then have to be sent away as radioactive waste. It may be best to condition the mud with cement (plus put it into plastic drums) before sending it away as these actions will make a release of radioactive muck less likely during transport.

The cement will not bind the cesium, but it will hold the radioactive soil particles in a solid which will not form mobile dust. The best thing may be to put the waste into a waste store. If this is left for 300 years then the cesium will decay away and the drums will be giant paperweights.

Be careful of two groups of people, one lot to watch out for are the professional doomsayers. They seem to be unable or unwilling to find a real and useful job and then they make their money by scaring the wits out of people. They will tell you that the Fukushima accident has extinguished all hope and that there is nothing which we can do to protect ourselves or clean up our environment. The second lot are those who claim that there is absolutely nothing to worry about and that you should ignore the results of the Fukushima accident. My advice is do not trust either of these “friends”, they are false friends who will lead you into different but equally bad places.

The age of the earth and where I have been

Dear Reader,

I suspect that some of my regular readers have noticed that I have not been blogging for a while. The reason why I have stopped blogging for a while is that I am in the process of writing a book. I saw something on UK TV today which is an outrage, it is the idea that the earth is only about 6000 years old.

Now while freedom of thought and speech allows people to hold and express what ever ideas they have, even the outlandish and odd ones ! But the idea that the earth is only 6000 years old is deeply disturbing and clearly wrong !

I heard one of the young earth creationists being told by a geoscientist about radioactive dating of rocks and minerals. The creationist said something to the effect of “how do you know when the clock was zeroed”. I know that in Africa many years ago a natural nuclear reactor operated. Some of the fission products such as Tc-99 have decayed away. This suggests that far more than 6000 years has passed since the reactors were in operation.

I will leave it up to my readers to look up the half life for Tc-99 and work out how long it will take for 90 % of the Tc-99 to decay to Ru-99. Think of it as homework.

Different reports on the same subject

Dear Reader,

In recent times we have had the first serious nuclear accident of the internet age, I am not sure why it is the internet age. The ‘ages’ were named after the materials used to make typical tools.

Stone age : Stone axes

Bronze age : Bronze swords made of a Cu / Sn alloy

Iron age : Iron ploughs

Then later the industrial age came, then we had the atomic age, the space age and then the internet age. My big problem is that for the majority of tools which we use in our lives we do not use atomic (nuclear), space or internet tools to do things like open cans of dog food or dig our gardens. For opening pet food cans and tending the vegetable patch I still use tools based on iron (steel).

While a nuclear powered digging machine or a space satellite which zaps the weeds might make life a little more easy (assuming you can afford to buy it) I think we will be sticking with steel spades and can openers for the forseeable future.

But I think that we do need to move onto something else. Recently a series of different reports have been published about the Fukushima event in Japan. Greenpeace have published a report as have the Japanese government and also Jon. M. Schwantes et. al. in the journal Environmental Science and Technology (DOI: 10.1021/es300556m) have published a paper in which they use the isotope signature of the accident to probe the event. In common with many things it is not always possible to make a direct measurement from samples which can be taken by hand, instead other measurements were used.

Now before we get going I will saw that it is impossible to have a single report which deals with a complex event in perfect detail. The problem is that if we examine one aspect of an event in great detail (using a state of the art study which includes as many details as possible) then this report is likely to become very large and close to impossible to read. If we then couple together a series of sections with a similar level of detail on all the different aspects of the event then we will end up with a wall of words which is impossible to comprehend.

Greenpeace have written about a recent Japanese report that

“The lethally high levels of radiation still present in the damaged reactors have prevented committee members from conducting a full analysis. They should be given all the time they need to complete their investigation.”

While the Japanese writers of the big government report stated that their mandate was

1. To investigate the direct and indirect causes of the Tokyo Electric Power Company Fukushima nuclear power plant accident that occurred on March 11, 2011 in conjunction with the Great East Japan Earthquake.

2. To investigate the direct and indirect causes of the damage sustained from the above accident.

3. To investigate and verify the emergency response to both the accident and the consequential damage; to verify the sequence of events and actions taken; to assess the effectiveness of the emergency response.

4. To investigate the history of decisions and approval processes regarding existing nuclear policies and other related matters.

5. To recommend measures to prevent nuclear accidents and any consequential damage based on the findings of the above investigations. The recommendations shall include assessments of essential nuclear policies and the structure of related administrative organizations.

6. To conduct the necessary administrative functions necessary for carrying out the above activities.

I have highlighted in bold the part which interests me most as a chemist, the Japanese panel  also stated that they would not undertake a series of actions which included.

“investigations that would require on-site visits to reactors with dangerous levels of radioactivity.“

My understanding is that they have chosen quite wisely to avoid either waiting for a full examination of the reactor sites (which will take decades) or rushing into a dangerous area to gather data. My view is that samples collected from outside the reactor buildings, eye witnesses from the site, data from those sensors inside the plant which continued to work together with details which can be obtained from undamaged BWR plants. I see the problem of the clash of two cultures.

The scientific and engineering communities are seeking to get the best quality report which is correct, the speed of publication of the report is a secondary factor. In these communities it is better to delay the publication of a report if the delay will allow the quality to be improved. Also the answer has to be traceable, the computational methods used, the persons who did the work, the devices used and the samples used all have to be documented clearly in this type of work.

On the other hand the newspapers and many of the green NGOs (like Greenpeace) are aiming for speed of publication as their highest priority. In these reports the things which were used to produce the final answer are often not as traceable. What is interesting is when both the rapid publication of people like Greenpeace agrees with the slower and more thorough investigation which goes into the official reports. I would say that it is important to avoid being caught by statements by “The findings of both these reports match closely with the Lessons
from Fukushima report released by Greenpeace in February” in a trap where you think that both reports are the same.

The Greenpeace report has some similarities with and some differences from the Japanese government report, but I would say that neither report deals at length with the containment chemistry and the radiochemistry of the accident. I am unsure of what Greenpeace would be hoping for in an extended report which might be written in 20 years time when the insides of the containments have been fully explored. I think that a main part of the final purpose of the examination of the reactor buildings will be to determine what chemical and physical effects occurred during and after the accident.

The Greenpeace report is more dominated by photographs which relate loosely to the event, I am unsure why it is important in a report of 52 pages to include devote ten pages to photographs of things like wrecked buildings with very little explanation of what is going on in the photograph. For example on page 28 a whole page is devoted to a person holding a pair of radiation meters in a field. There are a series of important questions which are not answered in the text such as “what level of radioactivity has the person found in the field”, “what is the testing protocol” and “what is the date of the measurement”. I hold the view that the report should be written in a way to make these things clear rather than forcing the reader to dig deeply in a series of documents for the answers.

The Japanese government report is much more text and far fewer pictures in the main body of the text than the Greenpeace report, towards the end a lot of data is presented in appendix in the form of graphs. These graphs include things like the fraction of the public who were aware at a given time of some key events. While graphs might be less eye catching than photographs, I hold the view that a well labeled graph is a better way to communicate an idea to another person than a photograph which has little if any commentary in the caption.

The problem I see is that if I show 100 people a photograph with very little writing in the caption then a danger exists that each of the 100 people will interpret it in a different way, while in recent years there has been a backlash against science made by people like the postmodernists. Some people value their “feelings” above everything else and express the view that a series of different interpretations of the same evidence are equally valid, I have to disagree. Firstly there is no such thing as an impartial observer (Read the section of the Alan Chalmers book “Whats this thing called science” on induction for more details).

Secondly some interpretations of evidence are deeply wrong, for example if I was photographed by an alien (who has no knowledge of pet ownership) while walking my dog in the forest the aliens might think (based on the photograph) that I am some sort of cruel person who enslaves small white animals and chains them up. While this interpretation might fit the evidence in the photograph it is deeply flawed.

As a result I think that a report which is dominated by photographs which do not have a clear set of captions explaining what is going on is not a good report. But a report which uses the same amount of space for graphs and figures which bear captions which explain all the key points does communicate in a better way with the reader.

The comment that Greenpeace made of “The lethally high levels of radiation still present in the damaged reactors have prevented committee members from conducting a full analysis. They should be given all the time they need to complete their investigation.” suggests to me that Greenpeace want the Japanese government report to be a comprehensive report which deals with all aspects of the event. It might even be understood as Greenpeace suggesting that their report is more comprehensive.

I have read both reports and I can say that some rather important things are missing from both reports. Neither report mentions the transfer of cesium from soil to plants and then to humans via the food supply. I hold a view that this is an important issue, depending on the soil chemistry, the biology of the food production system and what countermeasures are taken the cesium in the diet is either going to be a small issue or a large issue. Also neither report gives a detailed list of the radionuclides released from the reactors and the amounts which were in the cores during the accident.

One of the best reports on this issue is the paper by J.M. Schwantes et. al., this paper uses the relative amounts of the different radionuclides in soil samples taken from Japan to work out what happened inside the cores of the damaged units.

This paper concludes

1. Volatility dictated by temperature and reduction potential dictated the fraction of the radioisotopes which were released.

2. All coolant was likely to have evaporated by the time the containments were vented.

3. The damage to the fuel was extensive.

4. The vast majority of the less volatile elements such as plutonium, niobium and strontium were contained within the reactors.

In the paper it has been calculated that the ratio of released cesium to plutonium from the Fukushima event was 100000 : 3 which suggests that the Fukushima event was far closer to a pure cesium / iodine release than the Chernobyl event was. The cesium to plutonium ratio for Chernboyl was about 10 : 1. I had from an early time made this prediction as the Chernobyl and Fukushima events were very different types of accident. One was a power surge while the other was overheating.

The most interesting thing in this paper is the graph of soil activity / reactor inventory against the oxygen potential of the dominate oxide form. This graph suggests that the more thermodynamically stable the oxide is then the less of the element will be emitted. The good news from this graph is that worst elements (plutonium) will not be emitted. The only problem is that the graph has some points which are a long way from the trend line.

More barium was released than this graph suggests while less ruthenium and silver was released than this simple model suggests. I think that I can explain why less ruthenium was released, the most easy ways to release ruthenium are either as fuel particles (which did not happen at Fukushima) or as ruthenium tetoxide which would not form as the reactors stayed under reducing conditions during the accident.

Dose estimates

Dear Reader,

I have found an interesting document which is on the subject of the atomic bomb tests done years ago down under in Auz. Now before we get going, I do not want to get dragged into a debate regarding the rights / wrongs of nuclear bombs or the moral issues associated with bombs and their testing. What we will be dealing with here is just the reported facts.

A document has been released some time ago by the Australian government which gives estimates of the radiation doses which Australians were exposed to as a result of the bomb tests there.

What is interesting is that the doses are quite low, if the data in the document is true then the vast majority of the Australians were exposed to low doses of radiation. But before we look at the dose estimates lets look at what the current UK limits are.

The 1999 law (1999 Ionising Radiations Regulations) set the following yearly limits

20 mSv Radiation worker

6 mSv Trainees aged between 16 and 18

1 mSv The general public

While the 1980s Ionising Radiations Regulations set the upper limit for a radiation worker at 50 mSv per year.

If we look at table 7.27 in the report from down under we will see the results.

A. 78.9 % of the people involved had doses which were lower than the current UK limit for the general public (1 mSv). I hold the view that this low dose of less than 1 mSv is nothing to worry about.

B. Only about 4 % of people are in the above 20 mSv group, these are doses which would break current UK law for a radiation worker.

C. Very few people (19 people, 0.2 %) are in the above 50 mSv group. These doses are above the yearly limit in the 1990s for radiation workers.

D. About 6.3 % of the people had unknown doses, in some ways this is the most interesting and more worrisome group. Most of these people were in the Royal Australian Air Force.

What would be very interesting is if an alternative set of dose estimates or measurements exist from the same bomb tests. By the way if dose estimates get you angry, do not get mad at either me (I did not make the dose estimates) or someone else but do feel free to point out other dose estimates which you think are more trustworthy.

Clay again

Dear Reader,

Again we are turning out attention to clay, clay is a wonderful substance on which we play tennis on, make pots from and create art with. Clay is also important when cesium gets into our soil. I recently wrote a little on the subject of the clay minerals in the soils in Japan. Here is a useful set of lecture notes on silicate minerals, most clays seem to be silicates.

I have recently read that the soil from Japan holds tightly onto cesium, when soil which was contaminated by the Fukushima event was soaked in 1 M ammonium chloride solution (at 25 oC) only about 20 % of the cesium radioactivity was liberated from the soil. Then when this soil was treated with 1 M acetic acid only about 10 % more of the cesium was liberated from the soil.

It was also found that treatment with 1 milimole per litre sulphuric acid only was able to liberate less than 1 % of the radioactivity while 1 mole per litre sulphuric acid was able to liberate about half the cesium.

These findings suggest it will be hard to wash the cesium out of the soil, but if the soil is washed with ammonium chloride then the remaining cesium will be hard to transfer to plants. I suspect that as time goes on that the amount of cesium which can be transferred to the plants will become less and less as the cesium becomes more and more fixed to the minerals in the soil.

Update on your new best friend

Dear Reader,

Slightly more than one year ago I wrote about the new best friend of the Japanese people. Rather than a person who will go out and go for a karaoke session with you, drink beer with you or go for a walk in the park with you this new friend is one who can clean up your drinking water and keep your fruit and veg safe. Also this friend can help keep the milk healthy. Now you might ask what sort of super nice person can do all these things, or what sort of imp or kappa is able to do all these things.

The identity of this new friend is a bit more humble sounding, it is the clay in the soil. I have seen a recent paper by Naofumi Kozai, Toshihiko Ohnuki, Makoto Arisaka, Masayuki Watanabe, Fuminori Sakamoto, Shinya Yamasaki and Mingyu Jiang (Journal of Nuclear Science and Technology, 2012, 49(5), pages 473 to 478) in which the cesium behaviour in the soil is reported.

In this paper the soil was examined with X-ray diffraction. This found smectite, mica, hornblende, kaolinite, quartz, orthoclose, cistobalite, feldspar, stishovite, gibbsite, sodalite, olivine and sorosilicate minerals in the soils.

The smectite clay is rather similar to the illite clay which I showed a picture of recently. The two clays are related, I have seen a thesis which explains how the smectite clay transforms into illite clay. For your information the thesis is here. The difference between these two layered clays is in the anionic bread layers between the potassium jam. The smectite and the illite have slightly different layers.

A smectite clay, the oxygens are in orange red, the potassium ions in blue, the aluminium/silicon atoms are in sea green. Note that layers of potassium ions which look like slices of bread.

I think that both the smectite and illite are formed from mica, so I would say that the more mica in the rocks which formed the soil the better when you are considering cesium in soil. The mica is very similar to the two clays, again it is a layered solid.

Many of us know mica, it is a mineral which can be made into thin sheets. We will soon see why it is possible to split mica into thin sheets. It is easy to separate the mica by peeling apart the layers.

Here is a view of a mica (Muscovite) which was studied some time ago. (O.V. Sidorenko, B.B. Zvyagin and S.V. Soboleva, Kristallografiya, 1975, 20, 543-549). Should should see again that the solid is layered, the potassiums (blue) have anionic layers of alumo-magnesium silicate between them. I have shown all the non oxygen atoms in the layers as green.

Mica showing the layers of potassium ions between the anionic layers

The important thing about the mica is that the aluminium atoms are randomly mixed with magnesium and silicon atoms in the two layers. The authors of the paper I am working from expressed the view that one of the types of layers (the middle layer in the trilayer anionic layer) has 20 % magnesium and 80 % aluminium. While the two outer layers of the anionic trilayer have 28.4 % aluminium and 71.6 % silicon. The mica also contains some hydroxyl anions which I have been unable to locate in that solid. I have made a new drawing of the mica which shows the mixed aluminium/silicon and aluminium/magnesium layers in different colours to show you how the solid fits together.

Diagram of mica. The potassium ions are in blue. The mixed aluminium/magnesium sites are in grey. The mixed aluminium/silicon sites are in green. The oxygens are in a rather fetching shade of orange.

It is important to note that the green aluminium/silicon sites have a tetrahedral arrangement of oxygen atoms around the central atoms while the grey mixed magnesium/aluminium sites have a distorted octahedral arrangement of oxygens around the central atoms.

The hornblende clay is a very different mineral, I have looked at the crystal structure and it looks in some ways like a SBA-15 or MCM-41 to me. It has tube like holes which pass in one direction through the clay. These tubes are then filled with sodium and potassium cations. As the clay is so different, I suspect that it may behave differently to the layered clays which I showed you.

The mica based minerals can change the spacing between the anionic layers to suit a new cation which has a larger diameter than the potassium. In this way the larger cesium ions can be held in the solid. But in the case of the hornblende, I do not think it will be so easy to add a larger cation. I think that the holes will get plugged up and blocked by the larger cations.

Here is a view of several unit cells of the hornblende clay, the solid is a little disordered. It has a mixture of sodium (yellow) and potassium (blue) cations in the solid. Also note that it has grey calcium ions in the alumosilicate layers. The aluminiums are purple, the silicons are sea green and the iron atoms in the clay are orange. The oxygen is in a rather fetching orange/red as before.

A view of hornblende clay showing the holes in which the potassium/sodium ions go.

I will try and give you an update soon on the clay and the cesium.

Sheep and Chernobyl

Dear Reader,

I have just discovered that the Chernobyl related controls which were imposed on sheep farms in England and Wales have just been lifted. The radioactive cesium from Chernobyl will have become weaker because of the radioactive (physical) decay, while the cesium-137 will only have decayed slightly the cesium-134 will have decayed a lot by now.

I imagine that by now that the cesium will have migrated deeper into the soil, this makes the cesium less able to enter the grass. Also I am hoping that the cesium will be more tightly bonded now to the soil minerals, one of the problems with the hill sheep farms is that the soil is poor in potassium and the minerals which will bind the cesium are not present in large amounts. This will lower the Kd value for cesium in the soil as a result the plants will be more able to absorb the cesium via their roots.

I saw with interest that Naofumi Kozai, Toshihiko Ohnuki, Makoto Arisaka, Masayuki Watanabe, Fuminori Sakamoto, Shinya Yamasaki & Mingyu Jiang published an article (Chemical states of fallout radioactive Cs in the soils deposited at Fukushima Daiichi Nuclear Power Plant accident) in the Journal of Nuclear Science and Technology, 2012, volume 49, issue 5, pages 473 to 478.

In this paper the authors report some leaching experiments which have been done on cesium contaminated soil from Japan, they found that the majority of the cesium stayed in the soil even when the soil was treated with ammonium chloride and acetic acid solution. This suggests to me that much of the cesium is locked up inside the soil which will prevent both the easy washing of the cesium out of the soil and also prevent the plants absorbing the cesium with ease.

Testilying and the environmental movement

Dear Reader,

Twenty years ago or so the late Dennis Evans told me a story about some cops who thought that they would tell a “white lie” to protect society (I have no idea where this vile story occurred or if Dennis had made it up or not). What happened was these boys in blue raided a drug dealer’s hotel room. They find some packets of cocaine. Then to make sure that the man went away for longer they plant some extra packets of cocaine. I imagine that they wanted to make sure that the judge sent the vile coke dealer away for decades rather than just sending him to HMP holidaycamp for a few years.

The core thesis of the prosecution was that the man was a cocaine dealer who was mixing cocaine with sugar to turn a larger profit and that all the packets had come from a common source. The fact that different packets had different sugar levels made it look like the dealer was mixing purer cocaine with sugar to make a less pure grade.

The police’s expert issued a report on on cocaine content of each packet where he/she lumped all the adulterants together. It is a common habit for people in the illegal drug trade to mix illegal drugs with other materials to increase their profit. So it should not be a total shock for the police to have observed some evidence of such behaviour.

Dennis was contracted as an expert witness for the defence, he retested the cocaine and made a point of measuring the different sugars (glucose, fructose, sucrose etc) in the cocaine batches. He found a purer packet which the police claimed was the parent of the less pure cocaine contained a sugar which did not appear in the less pure packets.

Armed with this information the defence was able to prove that the story that the police were telling was false. They showed that someone (the police) had planted at least one packet in the room. They then suggested to the jury that all the cocaine had been planted in the room. The man then was acquitted on all charges and walked away from the court, I imagine without a stain on his vile character.

While some people might think “I have nothing to do with drugs” and “I am not a policeman” so this story has nothing to do with me. I would say that these people are being very foolish, this is a cautionary tale about telling a “white lie” to get the job done. This is an example of testilying and the vile perils it brings.

It is better to tell the truth about something even if you think by exaggerating that you will be more likely to get the outcome that you want.

Before we go any further I would like to make something clear to those of you who are not regulars here on my blog, I have to agree with the greens, antinuclear lobby or whatever you want to call them or be called yourself (if you are a member of the antinuclear lobby) that the Chernobyl and Fukushima events are horrible. These are events which need to be avoided where possible, and if total avoidance is not possible then these types of events need to be mitigated to eliminate the threat to the general public.

My (or your) revulsion at serious nuclear accidents is not however a license to exaggerate or attempt to use these events to score cheap political points. Frankly those who use these events for selfish ends disgust me just as much as the 19^th century mill owners who thought it was quite reasonable to force young children to work in dangerous factories, clean chimneys or go down the coal mine.

My loathing of serious nuclear accidents is one of the reasons why I devote time and energy doing research on trying to prevent a nuclear accident causing harm to the general public. In order to protect ourselves against reactor accidents we need to understand them, part of the quest to understand them involves a quest for truth and an insight. During this quest I am doing my best to share whatever grains of truth I uncover with others, and also to point out silly ideas when I find them. One of the things which irks me is when people exaggerate the consequences of an event, the fact that an event is horrible is not a license to lie. To me the exaggeration of the event is as wrong as a person falsely claiming that it is less bad than it really is.

It has been claimed that the cesium from the Chernobyl accident causes heart disease in adults and children, the core of the idea is that cesium goes into the heart and that the radioactive cesium then damages the heart. Next the person falls down dead from heart disease or at least becomes in invalid.

We need to ask ourselves if the radioactive cesium is able to damage the heart, some time ago (2008) a Yann Gueguen et. al. published a paper (Cardiovascular Toxicology, 2008, 8(1), 33-40) in which they exposed rats to cesium in their drinking water. The amount of cesium was 150 Bq per day for three months. Now the rats weighed 560 grams, which means that they were drinking 267.85 Bq per kilo. Now if we scale this up to a 75 kilo man then he would have drinking 20 kBq per day. As each year has 365.25 days then this 75 kilo ratman will be drinking 7.338 MBq of cesium each year.

We are making the assumption that the cesium behaviour in rats and humans is the same and that the same dose / activity coefficient should be used for both species.

Based on my ALI as a classified radiation worker which is 1.5 MBq of cesium-137 (oral), the rat man will be drinking 4.9 times the ALI which is based on a 20 mSv dose. So the 75 kilo ratman will get a 97.84 mSv dose from the cesium. So this amount of cesium is a very large amount of cesium.

I hold the view that if a member of the general public is getting a 98 mSv dose from an nuclear accident which happened decades ago that something is deeply wrong. This is a dose which is far in excess of what I am allowed to be exposed to at work. So while this study might be an interesting one it is set at a level of cesium which I think is too high.

I suspect that some differences between rats and humans exist, I have checked and the biological half life of cesium in rats is shorter (11 days) than it is in humans (B. Le Gall et. al., Biochimie, 2006, 88(11), 1837-1841). So rats are able to get rid of cesium from their bodies faster than humans can. The estimates for the biological half life of cesium in humans range from about 1 month to 4 months. If we take the UN’s estimate that biological half life to be 100 days then we can compare rats and humans.

I have done some calculations for rats and humans and based on the difference in the biological half life I think that cesium should be 9.1 times less toxic to a rat than it is to a human. So we should revise down out doses for the “rat man”. If we take this correction factor then the rat man used in this experiment if it had been a human would have had a 10.78 mSv dose (0.8 MBq intake)

Now I think a key part of the reasoning behind “chernobyl heart” is the idea that the cesium goes into the heart, I was looking in the literature at animal studies where the experimental animals were fed cesium-137. I found a second paper (Jean-Marc Bertho et. al., Radiation and Environmental Biophysics, 2010, 49(2), 239-248) where mice were contaminated with cesium-137 (20 kBq per litre) in their drinking water.

This paper stated that human exposure to cesium-137 in contaminated areas is in the range 20 to 2100 Bq per day, which works out as giving a worst case amount of 767 kBq per year. While I think that this amount of cesium is a large amount in the general public’s diet it is well below my ALI (Annual Limit of Intake) and far below the level which I worked out by scaling the rat up to the 75 kilo “rat man”.

The mice were feed the cesium in their diet from the age of four weeks onwards, I looked at the intake of the these mice and the females drank 465 Bq per week and the males drank 507 Bq per week. As the female mice (at 20 weeks) had a weight mass of 23 grams and the male mice had a weight mass of 30 grams we can make a first guess of what human level of exposure we are considering.

The 75 kilo “mouseman” would be getting 1.27 MBq per week while a 65 kilo “mousewoman” would be getting 1.31 MBq of cesium per week. This will work out as 66 MBq per year for the mouseman and 68 MBq per year for the mousewoman. This is a lot of radioactivity.

We are assuming here that the biological half life of cesium in mice is the same as it is in humans and that all other cesium biochemistry and biophysics is the same in both species. Again if we work out the biological half life of cesium in mice it works out being shorter than it is in humans. Using the data from J.M. Llobet et. al., Journal of Environmental Contamination and Toxicology, 1998,61, 289-296 it appears that the biological half life in mice is about 7 days. Thus based on the different biological half-lives the cesium will be 14 times less harmful to mice than men.

So micemen will now be getting an intake of 4.7 MBq per year. This is still a lot of cesium-137 to get in your diet.

Now back to the paper of Bertho, the important thing in this paper is that no clear signs of damage to the mice were seen. Also if you read the paper the radioactive cesium content of the heart (in Bq per gram) is less than the kidneys and the normal muscles of the mice. This paper makes me think that we need to take great care when we consider the possible link between chernboyl cesium and heart disease. This is because the cesium does not seem to be localizing inside the heart in the same way as iodine localizes inside the thyroid.

The next thing to be careful of is the fact that cesium-137 (together with its daughter barium-137m) emits three different forms of radiation. The average beta decay energy of cesium-137 is 188 keV, this is quite a low average beta energy when compared with yttrium-90 (933 keV) and phosphorus-32 (695 keV) but it is about the same as Sr-90 (196 keV). But it is a bit higher than carbon-14 (49 keV). So we can safely assume that some of the beta energy of the cesium which is in the heart will be deposited in the heart.

But 662 keV of the decay energy of the cesium will be in the form of gamma rays, even if the cesium is in the heart then much of this energy will escape from the heart. On average 363 keV of energy will fly away in the form of neutrinos. These are particles which are unlikely to interact with a slab of lead as think as the earth. So I think we are safe to assume that only part of the decay energy of the cesium which is in the heart will be delivered to the heart tissue.

Also bear in mind that the beta and gamma radiation are both low LET (Linear Energy Transfer) radiations. This means that ionization tracks formed by these radiations are long and diffuse, as a result these radiations are less able to damage living tissues. The issue of self repair needs to be considered, the background of radioactivity in a normal human body together with cosmic rays causes all tissue to be subject to ionizing events. The damage from most of these are repaired by the cells.

I think it would be a good idea if those who are making statements supporting the idea that cesium-137 causes cardiac damage to people should address the issues of how much cesium is in the heart and how much of the radioactive decay energy of the cesium is delivered to the heart.

Also they should consider the natural radioactivity (carbon-14 and potassium-40) which is in a normal clean and uncontaminated human body.

Well that is all for now, I will return with more of my thoughts later.

Mike Adams

Dear Reader,

It has come to my attention that a Mike Adams has published a claim that the spent fuel ponds at Fukushima are a dire threat which is likely to exterminate mankind. He claims that the release of “radiation would turn North America into a “dead zone” for humans… mutated (and failed) crops, radioactive groundwater, skyrocketing infant mortality, an explosion in cancer and infertility”

Now before I go any further I will address some of these bold claims. I think that on many things Mike is very wrong.

1. A radiation release from the spent fuel pond is very different to a release of radioactivity. I sincerely wish people would learn the difference ! The best way to think of it for the layman is to consider my dog, he sometimes barks and you could imagine the waves of sound coming from his mouth to be like radiation. His bark travels through the air obeying an inverse square law and with some distance from him the bark soon becomes less irksome. The dog is the object which emits the barks, you should think of the dog as being like the radioactivity. The barks from my dog might escape from the house when I open a window but the thing which emits the bark can not escape with the same ease.
2. As cesium (the most mobile of the medium to long term irksome radioisotopes) sticks like glue to clay, almost all ground water and wells will remain radiologically safe to drink from no matter what happens.

So with these two important mistakes, omissions, distortions or whatever you want to call them lets take a look at the rest of his article using the our intellect !

Mike wrote that the cesium release will snuff out all life in mainland USA; I very much doubt that this would be possible.

He assumes that all the cesium will be released, and that 85 times as much ¹³⁷Cs is in the ponds as was released at Chernobyl. I want to use the Chernobyl cesium in Scotland as a model for his proposed doomsday event.

I looked up the average level of ¹³⁷Cs in soil in the UK, in Scotland the level of this radioisotope as a result of Chernobyl is 1580 give or take 310 Bq m^-2 on moorland while it is 2510 give or take 510 Bq m^-2.[1] This might seem like a lot of radioactivity, but for a beta/gamma isotope this is not much. If we take the standard data[2] on ¹³⁷Cs we will find that the dose rate one meter above the surface of ground which is uniformly contaminated with 1 Bq m^-2 is 1.6 pSv hr^-1. So the dose rate due to the Chernobyl cesium in Scotland is 4.016 nSv hr^-1. Which works out as 35 microSv per year. This is not much !

If we assume that the Chernobyl release had been 85 times larger, then the yearly dose would be now 3 mSv per year. This dose will not exterminate humans ! The chances of getting cancer as a result of living 60 years in such a place will be small. Only 1 in 111 people will get cancer as a result of this exposure even if we ignore the radioactive decay of the cesium. Sadly about 1 in 4 people die of cancer from other causes such as bad diet, smoking and simple bad luck. As a result I would not expect to see any noticeable change in the population.

So we have caught him in another error, not too good !

I would also like to point out that Mike has not fully explained the mechanism by which he proposes that the cesium will be released from the pond.

The great problem with his idea is that the heat production in the fuel in the pond has gone down greatly, the fuel will hardly be emitting any heat by now. This makes it much harder for the cesium to be released from the pond. I would be very interested to see how he proposes the pond will belch forth the cesium.

To give you some idea of what Mike is like here is what he thinks of the UN, he thinks it is “a criminal globalist organization engaged in widespread sex slave trafficking, child abuse and mass murder”. The last time I looked the UN appeared to be much more benign than that. I recall that recently part of the UN (the IAEA) got a noble peace prize (they spent the money part of the prize on cancer care for people in the third world).

Some years ago the United Nations High Commissioner for Refugees (UNHCR), United Nations International Children’s Emergency Fund (UNICEF) and United Nations Peace-Keeping Forces have all been given Noble Peace Prizes.

I thought that the people in Norway who issue Noble peace prizes are careful not to issue them to bloodthirsty cut-throats and brigands.

This scorching condemnation of the UN does suggest to me that there is either something terribly wrong with either my understanding or Mike’s understanding of the UN. I think I will leave it up to my reader to judge the UN.

Before I do go, I would like to point out something. Fukushima was (and is) a horrible accident, but the horrible nature of the accident is not a license to exaggerate or lie. I fear that members of the Green movement who exaggerate or lie will do the environment a great harm, what will happen is that they will discredit the genuine concerns of those who want to protect the environment.

---

[1] A.S. Likuku, D. Branford, D. Fowler and K.J. Weston, Journal of Environmental Radioactivity, 2006, 90(1), 37-47.

[2] http://www-pub.iaea.org/MTCD/publications/PDF/Pub815_web.pdf

The C plan diet

Dear Reader,

I would like to express my thanks to Dr Susan K Burton (Associate Professor, Faculty of Foreign Languages, Bunkyo Gakuin University) who has provided me with a link to an English translation of an article based on a book by Kunikazu Noguchi (Nihon University) which is about how to reduce the amount of radioactivity you get from your diet. Kunikazu Noguchi’s book is aimed at the general public who quite understandably are worried about radioactive food.

You can read part of it at http://www.japantimes.co.jp/text/fs20110920a2.html

He wrote about vegetables, the release from the Fukushima plant was as a result of overheating fuel. This boiled the more volatile radioisotopes out of the fuel and formed some aerosol particles. These aerosol particles were able then to escape from the plant. Knowing what I know about iodine chemistry during a serious accident I suspect that much of this radioactive pollution was in the form of cesium iodide particles.

He suggests that vegetables should be washed before eating to remove the cesium, I hold the view that produce which was harvested shortly after the accident may have some cesium on the outside. As the cesium from the accident is in the form of a water soluble compound it should be simple to wash it off. I would like to point out that this washing will only remove the cesium which is on the outside of the plant tissue, some of the cesium may have been absorbed into the plant through the leaves. This fraction of the cesium will be impossible to remove by simple washing.

Next years fruit and veg will only be able to absorb radioactivity via the roots. So for next year’s crop the need to wash it to remove radioactive dust will be smaller. I would still advise you to wash your salad vegetables before eating them. This is mostly to remove the creepy crawlies.

The absorption of radioactivity through the roots will be controlled by the soil chemistry, in general the more clay in the soil the smaller the fraction of cesium which will go from the soil into the plants. What will happen is that the clay acts as a ion exchange material, according to L.N. Maskalchuk (Nuclear Engineering International, Soil Contamination in Belarus, 25 Years Later, 2012, page 16.)

I have explained already how the clay traps cesium, the illite clay is able to bind 1+ cations and it has the following strength of binding.

Cs+ > Rb+ > NH4+ > K+

I have already discussed this matter before so we are going to move onto something else. While the Fukushima event has released very little strontium into air, I will explain how we can do something about strontium in the soil. The strontium can exchange for calcium in minerals such as calcite and dolomite, in a similar way to the way in which strontium can mimic calcium in the minerals in bone it can swap with calcium in calcite and dolomite.

The domolite unit cell has the following dimensions

a = 4.795 Å

b = 4.795 Å

c = 15.87 Å

alpha = 90 degrees

beta = 90 degrees

gamma = 120 degrees

The volume of this cell is 315.998

The calcium atoms are at the following locations

0, 0, 1/2

1/3, 2/3,

1/6 2/3,

1/3, 5/6

The magnesium atoms are at the following locations

0, 0, 0

2/3, 1/3, 1/3

1/3, 2/3, 2/3

The carbon atoms are in the following locations

0.6666, 0.3333, 0.0733

0.0000, 0.0000, 0.2600

0.3333, 0.6666, 0.4067

0.6666, 0.3333, 0.5933

0.0000, 0.0000, 0.7400

0.3333, 0.6666, 0.9267

The oxygen atoms are in the following locations

0.9167, 0.5833, 0.0733

0.4167, 0.3333, 0.0733

0.6667, 0.0833, 0.0733

0.2500, 0.0000, 0.2600

0.0000, 0.2500, 0.2600

0.7500, 0.7500, 0.2600

0.0833, 0.6667, 0.4067

0.5833, 0.9167, 0.4067

0.3333, 0.4167, 0.4067

0.6667, 0.5833, 0.5933

0.4167, 0.0833, 0.5933

0.9167, 0.3333, 0.5933

0.7500, 0.0000, 0.7400

0.0000, 0.7500, 0.7400

0.2500, 0.2500, 0.7400

0.5833, 0.6667, 0.9267

0.3333, 0.9167, 0.9267

0.0833, 0.4167, 0.9267

The calcite has roughly the same cell. Now some of you good people will have drawn out the unit cell for your selves (well done you good and worthy people !) but for the rest of us who find cells where at least one of the angles is not 90 degrees a real pain. Here is the unit cell. The cell has blue calcium atoms, golden magnesium atoms, orange oxygens and dark gray carbons.

Unit cell of dolomite

What I think will happen is that some of the calcium sites in the dolomite will be replaced with strontium. I have checked the crystalographic literature and strontium carbonate has a very different unit cell to either dolomite or calcium carbonate (calcite).

Here is the calcite cell for you to look at, please compare with the dolomite cell.

Calcite unit cell

The strontium carbonate (Strontianite) has a very different cell, all the angles for the cell are 90 degrees. Here is the cell for you to look at and enjoy.

Unit cell for strontium carbonate

Now what I thought would happen is that the occasional calcium atom in calcite at the surface will be replaced with a strontium atom. I had these thoughts when I was out walking the dog, I later looked in the literature and saw that N.E. Pingitore et. al., Geochimica Et Cosmochimica Acta, 1992, 56(4), 1531-1538 which explains how EXAFS shows that the strontium forms a very dilute solid solution in the calcite.

If we start with a pure calcite then a face of it would look like this.

Calcite surface before doping with a little strontium

Now if we randomly replace some of the calcium atoms with strontium we get a solid solution of strontium and calcium carbonate which has a calcite structure. Now here it is, I have replaced four calciums with strontium.

Strontium doped calcite

What this means is that if we add powdered lime (crushed chalk or limestone) to a soil then whatever strontium is present in the soil will be more likely to be absorbed onto the surface of lime and thus be more unavailable to the plants than it would be before the lime was added. The key thing to understand that this is all about solid solutions, a solid solution is a solid which is part way between two solids with identical strucutres. The best way to think of it is to have an array of tennis balls on a table and to randomly swap some of the tennis balls for cricket balls. Sadly I do not have a pile of tennis balls or cricket balls, but here is a photo of some of my weekly fruit supply.

Nine of Mark's oranges laid out on a worktop

Now we replace one of the oranges with a lemon, note that the array of atoms fruits are unchanged in terms of how each one relates to the others. Then we can have a solid solution of oranges and lemons. Here is the photo of the solid solution.

A solid solution of oranges and lemons, well mostly oranges.

Well I will have more to show you soon, so stay tuned !