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.

Radioactive waste from wind power

Dear Reader,

I am sure that many people have told you of the green nature of wind power, it is sold to the public as the ultimate green energy production system. It has reached the point at which it seems like nobody is allowed to say anything bad about wind farms, but we need to keep our wits about ourselves.

Many high tech and green gadgets need rare earths (lanthanides), the name is a bit of a misnomer some of the lanthanides are very common in the earth. But some of them are very rare elements, the worst bit is that the rare ones are the more useful ones. For example the red phosphor in a colour TV is traditionally europium doped yttrium oxide or europium doped yttrium oxysulfide. Europium is a rare lanthanide which often forms compounds which emit red light.

Now with many gadgets such as electric cars and windmills people think they are green because they do not release any pollution during use, it is important to understand that a gadget such as an electric car is not a “zero emissions vehicle” it is an “emissions elsewhere vehicle”. One emission type are those which occur during the use of the machine and the others are those associated with the production and final disposal of the object.

If we ignore the emissions during the building of the gadget and its disposal then a nuclear power plant is perfectly green, it emits next to no pollution during use. It is only during the fuel production, building of the plant and the disposal of the fuel that the releases of pollution occur. It is clear that we must consider the whole lifecycle of the parts of the system.

In the case of the lanthanides it is important to understand that the processing of lanthanide ores produces radioactive waste, the problem is that much of the world’s lanthanides are in thorium rich minerals such as the monazite phosphate minerals. As a result when monazite is processed often radioactive waste is produced.

The nasty thing about natural radioactivity in rocks and minerals (harmless or cute sounding) is that it tends to be alpha emitting and often mobile in the form of radon / radium. On the other hand much of the radioactivity in the back end of the nuclear fuel system (scary sounding reactor waste) is short lived beta / gamma emitting fission products and a little alpha emitting waste. Much of this alpha emitting muck is plutonium, while plutonium might sound like a total nightmare it is important to note that it is very immobile in the form of oxide fuel. Firstly it is very insoluble in water and secondly plutonium absorbs very well onto mineral surfaces. To use some non technical language it sticks like glue to mineral surfaces, thus it will not migrate through soil and rocks with ease. Once the plutonium is buried then it will be locked up in the rocks for many thousands of years.

On the other hand radium and radon can move around in water with ease, these elements will not bind so well to mineral surfaces. The waste from lanthanide ore processing is sometimes codenamed TENORM, this means Technologically Enhanced Naturally Occurring Radioactive Material. This TENORM is a major pain in the oil / gas industry and in the ore processing industry.

The best way to reduce the production of this radioactive waste is to recycle lanthanides, by reusing lanthanides instead of mining ore the volume of radioactive waste will be reduced. If you want to support green devices such as hybrid cars and windmills then it is up to you, but I would urge you to lobby for the valuable metals and other materials to be recycled when these products reach the end of their useful lives. If no sensible recycling method exists then a need exists for more research on recycling, one of the things which I am involved with at Chalmers is the Industrial Materials Recycling section. Here we study the recycling of that which can not be currently recycled.

The health condition of the Fukushima Children in Ginza, Tokyo .

Dear Reader,

I saw this film recently, it makes some claims that the Fukushima reactor accident is making children sick. I think that this film raises some interesting points.

Appeal concerning the health condition of the Fukushima Children in Ginza, Tokyo ..

There is a problem, if the above average level of radiation in Japan is able to make children ill then why is Ramsar in Iran not famous for ill children ? In this place in one year the background radiation dose is normally more than 100 mSv.

In Japan it has been decided that if the dose rate is greater than 20 mSv that people will be relocated, so the people in Ramsar should be more ill than the general public in Japan near the Fukushima reactor accident site.

One of the people in the film had to go for a CT scan, I would like to know if anyone has considered how this is likely to have involved quite a large X-ray dose. While people get concerned about an exposure from a reactor accident, many people do not seem to be as concerned about medical exposure (due mostly to X-ray radiography). This is something which I can never understand.

Also if the children of Fukushima were being exposed to so much radiation that they feel ill as a result (chronic radiation syndrome ?) then I imagine that their blood counts would be rather abnormal. If for argument’s sake they were so strongly exposed then blood samples from them would show signs of radiation exposure.

For a large dose, I would expect cell counts to be abnormal. At lower doses I would expect a much higher number of chromosomal abnormalities per litre of blood. If someone can bring us this type of evidence then I will believe that the children of Fukushima have been exposed to a lot of radiation, but until I am presented with such evidence I will remain very suspicious of the claims of these radiation related illnesses. The thing is that to induce the non cancer effects which appear shortly after a radiation exposure a very large dose is required, and the dose must be above a threshold. Below the threshold the effects can never be seen.

It is a bit like alcohol, humans and drunkenness. To get a person drunk requires alcohol, the more alcohol you feed them the worse the drunkenness becomes. Below the threshold dose it is impossible to get the effect of drunkenness, for example if 200 people take communion at a church and have a tiny sip of wine then non of them will come out of the church as crazed drunks (Unless they were drunks before the service). I hold the view that as a result of Fukushima that no member of the general public has had a radiation dose which is able to cause one of the deterministic effects which appear shortly after the radiation dose is delivered to a human.

Even after the much worse Chernobyl accident no members of the public were stricken with the deterministic effects of radiation (radiation sickness), so I would suggest that my readers take care when they here of claims from Japan about the radiation making children feel ill. We need to have a respect for the truth, part of a respect for the truth is to resist telling lies or making exaggerations even if you think (or know) that the thing you want to warn people against is very bad. One of my roles at Chalmers has been to help supervise research on serious nuclear accidents, I can tell you that serious nuclear accidents are thankfully rare but they can be horrible even without inventing new effects or exaggerating the effects.

Honesty about the things we dislike

Dear Reader,

When I recently saw the comments of Yehuda Bauer about one of the most horrible tales (large scale production of soap from human fat) from the 20th century, this gave me reason to think. He wrote

“The reason why one has to be accurate is that one has to exercise tremendous responsibility and deep respect towards the victims and their relatives and towards the memory of the millions of Jewish dead. What the Nazis did is horrendous enough; we do not need to believe the additional horrors they thought about but did not have time to realize. The Holocaust deniers waiting in the wings are eager to pick up any inaccuracies we may inadvertently commit, and we should not ease their “work.” “

The key take home message is that there are some very horrible things which have occurred, but to make up (or repeat) lies about these events to make them even worse is wrong. These lies are evil (I do not use the E word lightly) as they distract us from the truth and then these lies make it more easy for those who wish to deny that the truth occurred to do their vile “work”.

Also such lies are deeply disrespectful to those decent people who were involved in these events.

I have seen a disturbing trend for people to be very reckless with the truth when considering threats to health and the environment. I hold the view that we need robust environmental rules which are based on honest reason and science rather than on hype, hysteria and on the ability of a group to shout louder than others. In the same way as industry should not be able to dictate the law, the environmental pressure groups should not be allowed to dictate the law.

I am sure that my readers would be unhappy with the following arrangements

1. BP and Shell being put in charge of setting and enforcing oil field health, safety and environmental rules.

2. AECL (Atomic Energy of Canada Limited) and BNFL being allowed to choose the nuclear safety laws

3. Ford motors and Volvo being allowed dictate all the laws which relate to the use and ownership of cars, trucks and buses.

In the same way we should not allow the environmental pressure groups to dictate the law, I think that we need laws to be made in a more fair way. I think that one of the best swords in our armoury against the worst nonsense which is based on either industrial self interest or the self interest of the pressure groups is to ask them to provide details of the logic and data which are behind their claims.

I have noticed a worrying behaviour in some activists, when questioned about their views and the things which they claim they get angry and make comments “I am telling it as it is” or they play the card “that unless you have experienced it first hand, then you are not entitled to have an valid opinion” or try a series of other tricks.

Fukushima report

Dear Reader,

The government in Japan has published a report on the subject of the Fukushima accident which some of you might like to read. If you want to read it then please click here.

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.