crosspost: “a nuclear Katrina in the making”

[bananas]

I'm linking to a post in a thread about DHS deciding to allow people back in right after a dirty bomb goes off. The post quotes a NYT article, and I didn't know how to reproduce the bold highlighting.

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=102&topic_id=2019120&mesg_id=2019403

3. ... “a nuclear Katrina in the making.”

(bold highlighting is mine) -

snip/

The document issued Tuesday lists a variety of factors, including the cost of cleanup. Mr. Hirsch and a second antinuclear group, the Nuclear Information and Resource Service, said that the 10 rem figure would produce cancer or leukemia in one person in four who was exposed to that amount annually for a total of 30 years. The two groups called the advice “a nuclear Katrina in the making.”

snip/

The department characterized its advice as a draft, because, it said, it would take public comment until March 6, but the advice takes effect immediately.


(bold highlighting is mine)

[aquart]

1. Yes, but we won't die immediately.

And everything we have, every memory we cherish, will be in those problematically-contaminated homes. Which will look just fine.

If we can go home, we WILL go home.

I live in downtown Manhattan and damn straight I've thought about it.

I also have an uncle who's had leukemia for thirty years.

[ddeclue]

2. Everything in technology is a tradeoff and a risk..

I'd much rather have nukes than to keep burning coal, polluting the atmosphere with heavy metals, soot, other particulates, NOx's, SOx's, and greenhouse gases COx's by the thousands of tons everyday as we do now. These ALSO pose cancer, cardiopulmonary and other health risks as well as environmental risks just in NORMAL operation, not an accident.

To put it in perspective, as bad as Chernobyl was, only 50 people have died from the radiation effects of Chernobyl. Coal plants kill more than that every year in NORMAL operation from their pollution.

And no, I'm NOT a Republican, I AM a Democrat before you bash me and call me a Freeper.

(Please read my posts at www.brainshrub.com/blog/121, in fact my current post is on renewable energy, ANWR, and energy independence, and the environment.)

I'm just an engineer and understand that nuclear power is not the bogeyman that lay people think it is.

Doug D.
Orlando, FL

[Dead_Parrot]

3. Welcome to E/E, Doug...

Don't worry, you're not alone in your assesment of nuclear power - quite a few of us have reached the same conclusion...

:)

[ddeclue]

5. Thanks...

Where did you get that cool environmental avatar?

People don't realize also that when a coal plant releases hundreds of tons of CO2 that some of the carbon in the CO2 is radioactive Carbon 14 and the same goes for the heavy metals released that there are plenty of radioactive material in this too. And this is NORMAL operation, not an accident.

Doug D.

[struggle4progress]

6. There's essentially no C-14 in coal. eom

[NNadir]

7. No, but there is a lot of uranium and decay daughters.

http://www.ornl.gov/info/ornlreview/rev26-34/text/colmain.html

As this link makes clear, if nuclear power plants released as much radiation as some coal plants, they would be shut.

Of course people don't care about coal so much as apologize for it.

[struggle4progress]

9. Your link calculates something like 2,630 curies produced annually ..

.. from US coal facilities in the US assuming something like 154 GW-yr production (or approximately 17 Ci per GW-yr).

NRC data clearly establishes that your claim "if nuclear power plants released as much radiation as some coal plants, they would be shut" is false, as has been pointed out to you a number times previously.

Reactor releases may occur irregularly but can be large; here are some random numbers available online from the NRC site (where much of the data is not actually available online). Diablo Canyon released about 300 Ci of tritium in 2002 (use Adams accession #ML031150420 at http://adamswebsearch.nrc.gov/scripts/securelogin.pl ). Limerick units 1 and 2 released over 1200 Ci of fission and activation gases in 2002 (Adams accession #ML031250356). Oconee released about 180 Ci of tritium in 2002 (Adams accession #ML031220310).

It's actually not uncommon for a single US reactor to releasing over 2000 Ci of tritium in a year. The Palo Verde Annual Radioactive Effluent Release Report for 2001 ( http://hps.ne.uiuc.edu/natcenviro/effluentreports/2001/Palo%20Verde.pdf ) asserts on page 13:
"Tritium production is approximately 1000 curies per Reactor Unit per year. In order to control plant tritium concentrations, tritium releases should match tritium production. For 2001, PVNGS released a total of 2880 curies of tritium ..."

[NNadir]

10. It just gets betterer and betterer, no?

You will keep in mind that I don't read the largest fraction of your posts, although I will certainly be addressing this precious bit and I promise to read every post you offer in this thread no matter what my opinion of it and its author.

We can of course count up all of the "curies" released by various technologies - if we ignore several important radiological parameters - the position of radioequilibrium between an isotope that is largely 1) gaseous and liquid, 2) diffuses 3) has a single decay in the decay chain and a 4) 12.33 year half-life, is a pure beta emitter, with a decay energy of 0.019 MeV, and exhibits no chemical toxicity 5) is released in gram quantities, 6) and distributes throughout the hydrosphere at speeds up to 600 m/s with a radioactive substance that is 1) a solid, 2) concentrates physiologically, 3) is a more serious chemical toxin than it is a radiotoxin, 4) is the member of a decay series having 13 decays, many in the 5 MeV range, alpha, gamma and beta, and has members of the series with half-lives ranging from billions of years (not so radioactive) to minutes (extremely radioactive) and is released in thousands of metric tons.

The first case applies to tritium released by nuclear plants, and the second applies to uranium (two isotopes) and thorium released by coal fired plants.

Actually, people who have a remote clue about risk, know that radiotoxicity is not measured in "curies;" it is measured in units like REM, gray, etc. We will refer to these radiotoxicity measures in our subsequent discussion, so google.

But I really don't have time for addressing much precious stupidity right now, since I have to eat and don't want to throw up but I will return to this wonderful bit of propaganda before it is all over. I will only note that every single atom of tritium produced in a nuclear reactor constitutes one atom of uranium destroyed forever. This is a law of physics.

We will also address issues of radioequilibrium and of course the vast number of people of South Carolina and Arizona who have been killed by tritium, presumably numbering in the tens of thousands, no?

There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[ddeclue]

11. Excellent couple of posts and good points.

I would have thought that C-14 would also have been a concern given that it is a naturally occuring isotope (albeit small) of carbon and carbon is basically what makes up the largest part of coal. Any small percentage would still amount to a large annual release however because of the hundreds and thousands of tons of coal burned at a plant every year. I knew that the heavy metals included uranium, etc. but I thought that first the amount of uranium was so small that when you looked at the radioactive isotope of it it would be a second order effect.

Apparently there's a lot more uranium than I thought! Egads!

So I agree with your final sentence about "risk minimized" energy.

This is not to say that we can't still start giving tax credits for people and businesses who put solar panels on their roof, etc. however and that the only answer is nuclear. I just know that the wrong answer is coal.

Doug D.

[Dead_Parrot]

13. C14...

Has a half-life of about 5,000 years: Since coal tends to be 50,000,000+ years old, most of the C14 decays long before it reaches that stage (Although you will find it in peat: maybe in detectable amounts in lignite).

As you say, C14 occurs naturally, so if anyone digs up your corpse in 2000 years time, they'll be able to tell almost exactly when you died from the decay of your natural radioactivity... :)

Except, of course, radioactivity is evil and must be destroyed.

(:sarcasm:, just in case)

[ddeclue]

16. Did not know that coal was that old...

I understand the radioactive half-life logarythmic decay curve but had no idea that coal was that old..

To paraphrase Dr. McCoy on Star Trek: "Dammit Jim, I'm an engineer, not a geologist."

Doug D.
Orlando,FL

[NNadir]

14. The first thing we need to consider in comparing the radioactivity of coal

power plant releases with the radioactivity resulting from nuclear power plants from the release of tritium, (tritium being the object of some peculiar obsession with some people apparently) is the nature of radioequilibrium.

It may take me several posts to discuss this topic, since it involves some technical issues and definitions that, while they are not immediately obvious, should be relatively easy to comprehend with a little reflection. This issue is important since it has direct bearing on how much tritium can exist as a result of the operation of nuclear reactors. This has bearing on the absurd contention advanced in this thread that the radiation released by tritium produced in nuclear reactors is actually worse than the radiation released by coal fired power plants.

In a nuclear reactor, tritium, hydrogen-3, the only radioactive isotope of hydrogen, is produced by a somewhat improbable reaction. Normal hydrogen as is found in water, contains, as many people know, two isotopes. The vast majority of the hydrogen on earth is hydrogen-1, aka "protium," the nucleus of which is simply a bare proton. However, hydrogen contains a small amount of a second isotope, hydrogen-2, aka "deuterium, about 0.015%, which has a neutron as well as a proton in the nucleus. It weighs therefore about twice as much as protium. It is NOT radioactive.

While the chemical properties of protium and deuterium are very similar - almost identical - both form water, and proteins, sugars, hydrides and all of the other magnificent compounds associated with hydrogen - their nuclear properties are very different.

When neutrons interact with matter, they can do several things, two of the most important such things being to bounce of the target nucleus, scattering it (with a change in energy for both the incident neutron), and absorption, in which the incident neutron is captured and becomes a part of the original target nucleus. When a neutron is scattered, some of its kinetic energy, a function of its speed, is transferred to the target. Thus the neutron is slowed down. It happens that smaller, lighter targets can transfer more energy from the neutron to itself. When a neutron is slowed down, it is said to be moderated.

Deuterium is much less efficient, for instance, in slowing neutrons down than protium: Where it takes, on average, 14 collisions between a neutron and protium nuclei to slow the energy of a neutron from 2MeV (the normal energy at which neutrons are emitted from fissioning nuclei, to 1 eV, one two millionth of its original energy. For deuterium nuclei ("deuterons") however, the average number of collisions required is 20. (For carbon 12 the average number of collisions required is 91; for the "average" iron isotope, 411 such collisions are required).

Since protium is an excellent moderator, it is widely used in nuclear reactors to slow neutrons down. Slow neutrons are better at effecting fissions than are fast neutrons for most actinides. Therefore most reactors rely on simple water to slow neutrons down.

The second thing, as noted, that a neutron can do is be absorbed. The probability that a neutron will be absorbed is different for every target, and this important distinction is NOT a function of chemistry: Different isotopes of the same element will behave very differently with respect to their ability to absorb neutrons. This is very much the case for protium and deuterium. The unit with which this probability of absorbing neutrons is named was whimsically called "the barn" by nuclear pioneers. It is a unit of area. One barn is 10^(-28) square meters. It is the area that a neutron "sees" when it is "deciding" whether to be absorbed or scattered. If the area is large, the probability of a neutron being absorbed (as in "hitting the side of a barn") is large. The number of barns characteristic of a this probability for a particular nucleus is called its "cross section."

The probability that a neutron will be absorbed depends on how fast it is going, but for simplicity we will only consider neutrons that are moving as slow as possible in water at normal temperatures, about 0.025 eV. Such neutrons are said to be thermalized. For protium the cross section for capture of a 0.025 eV neutron is 0.332 barns. For deuterium, the cross section for capture is 550 microbarns. Thus a protium nucleus "appears" to be about 600 times larger to a thermal neutron than does a deuterium atom, if one is speaking of the tendency for a neutron to be absorbed.

These values (and many other interesting nuclear properties) can be found by clicking on the appropriate links in the table of nuclides: http://atom.kaeri.re.kr/index.html

When a neutron is absorbed by a protium nucleus, the nucleus is, of course, converted from hydrogen-1 to hydrogen-2, deuterium, and the radioactivity of the water is unchanged since deuterium is stable. When a neutron is absorbed by deuterium however, it is converted into hydrogen-3, the famous (or in the case of radiation paranoids "infamous") tritium. This then, is how tritium is formed in nuclear reactors, by absorption of neutrons into a previously stable nucleus to form an unstable or radioactive nucleus. Radioactivity that results from this type of process is called "induced" radioactivity. Induced radioactivity is a normal process in all materials found in nuclear reactors.

In my next post in this thread, I will examine the rate at which tritium is formed and, just as importantly, the rate at which it is destroyed by transformation, through normal nuclear decay, into helium-3. We shall see that this situation is represented by an equilibrium in which formation is balanced by decay. This will necessarily involve a small amount of mathematics in the form of a rather simple differential equation, but if one is uncomfortable with mathematics, one can simply gloss over the matter and focus on the result. It will obviate a comparison of the total environmental radioactivity attributable to the emission of chemically toxic uranium and thorium in coal ash and the tritium released by nuclear plants.

This will help us to the truth: There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[Dead_Parrot]

15. Thanks, NN - I've learned something... nt

[NNadir]

22. The production-destruction equation, some preliminaries.

As we have seen in my previous post, the number of decays experienced by a radionuclide is proportional to the amount present.

When most fresh nuclear fuel is loaded - and for now, for simplicity only - we will not consider the MOX fuel that will become increasingly important as the world shifts to nuclear energy - the only radioactive materials contained in the fuel are naturally occurring materials, usually uranium, but sometimes thorium. Initially, there are no fission products, except for those resulting from the tiny amount of spontaneous fission that always occurs in uranium.

When the reactor begins to operate however, a neutron flux is deliberately created, in such a way, as most of us know, so that a chain reaction occurs. A flux, in physics, refers to the passage of some entity - it may be theoretical as in magnetic flux lines, or physical as in neutrons - through a unit of area. A neutron flux, therefore is a measure of a number of neutrons passing through a unit of area.

The majority of the times that an atom of uranium-235 is struck by a thermal neutron from a neutron flux, it splits, producing between 1 and 3 new neutrons, with the average number being, depending on the energy of the incident (splitting) neutron, being somewhere in the neighborhood of 2.2 for uranium-235, and higher for uranium-233, an isotope created by the transmutation of thorium. If these new neutrons strike additional atoms, fissioning them, the neutron flux increases until either a sufficient number of them leak out of the uranium into the surroundings, or neutrons are absorbed by a material deliberately placed in the path to prevent the flux from increasing further.

It should be obvious, of course, that the success with which a neutron from a flux encounters an atom of uranium that is suitable for being fissioned is a function of how many atoms are available in the path for it to strike. The number of atoms available to be struck by neutrons is therefore a function of the density of the substance and its atomic mass. As before, these conceptions can be understood by appeal to concepts generally taught in high school chemistry. As mentioned in an earlier post, the ability of a neutron to interact with a nucleus is also a function of how "big" the atom is: This is the cross section as I described in a post above. Cross sections exist not only for absorption and scattering as I described for the hydrogen isotopes protium and deuterium, but, for elements with atomic numbers beyond polonium in the periodic table, but for fission, or splitting, as well. Generally the cross sections are not the same for fission, absorption and scattering: How "big" the atom appears to a neutron is a function of which type of interaction you expect the neutron to cause.

Earlier I described what a "barn" is, 10^28 square meters. When one refers to barns, one is describing what is known as the microscopic cross section, which is generally designated in nuclear engineering and physics texts by the lower case greek letter sigma. In the subsequent discussion because of the limits of the editor, I will use a lower case s.

As stated though, two factors are important for the probability: cross section and the density (number) of atoms. For this reason it is useful to designate the macroscopic cross section. This quantity is usually designated by a capital greek letter sigma. I will use S. The macroscopic cross section is defined as the product of the number density of a nucleus. The number density, in turn, is simply the physical density of a material w/V times Avogadro's number, divided by its atomic number. If we (for the purposes of this post only) designate Avogadro's number as No, the number density, N = No*d/A where d is the density and A (for the purposes of this post only) is the atomic number of the atom. S, the macroscopic cross section, is defined as the number density N times the microscopic cross section, ie S = Ns.

In order to explore the production-destruction equation mediating radioactive equilibrium, we will have to know what S, the macroscopic cross section is. If one wishes to skip the math, one need only know that only some neutrons interact with matter as they pass through matter, and that this is an expression of a probability, determined by size and number of atoms in the volume of matter in question.

Note that the number density for deuterium in ordinary water is very low: Only 15 out of every 100,000 atoms of hydrogen is deuterium. Therefore macroscopic cross section of deuterium in water is also low. The practical consequence of this is that in nuclear reactors moderated by ordinary water (but not CANDU reactors) the probability of a particular neutron striking a deuterium nucleus and forming a tritium nucleus is small - and in any case, even when it happens, there are many more unreacted atoms of hydrogen (mostly protium) around.

The conceit of anti-nuclear coal apologist morons is to pretend that the consequence of the existence of tritium means that it will find itself, with absolute certainty through magic, inside a living system - generally they want you to think that the living system in question is you, because basically they are scare mongerers with paranoid fantasies of their own. However, as we shall see as we further explore the question of whether the radiation from coal plants is far more dangerous than the radiation from nuclear plants, this is pure nonsense. In an nuclear reactor a tritium atom doesn't jump out of a reactor and make a beeline for cute babies about to be studied by Ernest Sternglass and other retards of his ilk. In fact the tritium has to compete with lots of other hydrogen atoms, both those coming from inside the reactor and those outside of it, for access to your flesh. Tritium atoms ultimately find themselves at the highest reaches of the atmosphere, and at the depths of the deepest trenches of the ocean, where like trees in the forest, they decay and no one notices. The issue is one of statistics, of probability. Further examination will reveal the question of human risk from this particular source to border on the absurd, not that the radiation paranoids want you to understand this.

For now I have defined one important variable that will appear in the production-destruction equation, S, the macroscopic cross section. I will need to describe a few more variables and the equation itself in subsequent posts.

In this way we will learn the truth: There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[struggle4progress]

24. Uh, tritium actually appears as a fission product in reactor fuel:

"... An actinide nucleus typically splits into two fragments when it fissions. But once in approximately every <edit: format> 10^4 binary fission events, an actinide nucleus splits into three fragments. Tritium, 3H, is a major ternary fission product ..."

Deep-Earth reactor: Nuclear fission, helium, and the geomagnetic field
D. F. Hollenbach*, and J. M. Herndon
http://www.pnas.org/cgi/content/full/98/20/11085

[NNadir]

26. The deep earth reactor is speculative, not generally accepted.

Most people believe that the heat of the core of the earth is best explained by nuclear decay, primarily of the huge amounts of uranium, thorium and potassium-40 that are contained in the earth.

One can see fission yield probabilities in commercial reactors by reference to the Table of Nuclides, not that many radiation of paranoids have referred to the table of nuclides, since they comprehend very much about nuclear physics, relying mostly on googling.

http://atom.kaeri.re.kr/

The important fission yields of every known isotope is given there. For instance, the direct fission yield for the (non-radioactive) isotope cerium-140 is 0.00% for direct emission of a fission product and 6.11991% for accumulated fission products (via isotopes with the same atomic mass number and lower atomic number) for 1.0 MeV fission neutrons impinging on uranium-235. For thermal neutrons interacting with Pu-239 the corresponding yields of Ce-140 are 1.80058 X 10^-5% direct and 5.55810% accumulated. You can, in fact, look it up.

Tritium yields from fission resulting from incident neutrons are not reported in the table of nuclides because they are trivial, just like tritium risk.

Spontaneous tritium emission is related to alpha radiation, albeit with a very, very, very, very small reaction probability. There is also a known spontaneous C-14 emission from some heavy nuclei, but again the reaction probability is very small.

In general, returning to neutron induced fission, the yield of specific fission products is a function of incident neutron energy. People who actually know more science than they can google recognize immediately that even in the dubious case that the core of the earth were a nuclear fission reactor, there is no moderator. Thus the applicability to the situation in nuclear reactors is generally trivial, since there are very few fast fission reactors operating in the world today.

All nuclear reactors have a fast fission fraction, however, and occasionally there are some spallation type fissions resulting from this fraction. (I have had an anti-environmental anti-nuclear moron on this website inform me that the fast fission fraction does not exist - this as part of a stupid claim that no uranium-238 is ever fissioned in thermal reactors.) These are, again, trivial events. In any case, the total burden of tritium, as we shall see as we further explore the matter, is of completely unimportant when compared to say, the greenhouse effect or chemical toxicity of heavy metals released by coal.

For the record, on discharge, ORIGEN calculations predict there is 574.4 curies of tritium per metric ton of metal in nuclear fuel in light water reactors. In fast reactors the yield, again according to ORIGEN is 1648 curies per metric ton of heavy metal. (cf, Stacey, Nuclear Reactor Physics, Wiley 2001, page 225.) This is not quite the same thing as saying that each curie of tritium will migrate into the pathetic brains of Greenpeace members. Most Greenpeace members, like most people on the planet, have an inconsequential amount of tritium in their brains in spite of all their crazy ranting on the subject of tritium. Their stupidity seems to have a different origin than radioisotopes lodged in their tiny brains.

In fact most of the spallation tritium in the fuel is contained in the fuel, just as most of the helium on earth is contained in granite after it is created by natural decay from uranium and its daughters in granite.

The main source of tritium releases in nuclear reactors are connected with induced radioactivity in the moderating water, although some, a tiny amount comes from cracked fuel rods, particularly in older reactors where such cracking was a historical problem.

When we look, as we will, at the specific activity of tritium, we shall see that the specific activity of tritium is over 9,000 curies per gram. Thus a release of thousands of curies of tritium represents the release of milligram amounts. When we compare this with the number of grams of water on the planet we shall also see that the likelihood of a particular atom of tritium ending up in a person's flesh is vanishingly small, and consequently the risk is vanishingly small.

Tritium is a spallation product of high energy collisions between particles including atomic nuclei. This accounts for the origin of tritium in the high atmosphere of earth and other planets. The steady state production of tritium in the atmosphere accounts for about 7 kg of tritium, which is about 68 million curies.

However, like the objections to nuclear power, this effect is trivial, since many other naturally occurring radioisotopes dwarf the 68 million curies of naturally occurring tritium.

The production-destruction equation accounts for fission yield, as I will show, but the effect of tritium yield is so small that it can effectively be ignored, as I will also show. In fact the production-destruction equation is designed for fission products. A higher yield (as is the case if it is both a fission product and a capture product as opposed to simply being capture product) of an isotope slightly effects the position radioequilibrium, but not hugely so. Equilibrium is still obtained, just as it is in the atmosphere.

The Oklo reactor, a thermally moderated naturally occurring nuclear reactor that operated about 2 billion years ago, however, is well understood however and well characterized. It is the primary experimental evidence that radioisotopes do not - in spite of the misrepresentations of people with elevated levels of paranoia - migrate very far in geological formations - even those that are porous sandstone in rain forests. The discovery of the Oklo phenomena has attached some data on the wild claim that every radioactive isotope created will necessarily and miraculously tunnel with intent into the flesh of some unsuspecting individual. This is nonsense and it has always been nonsense.

This has been another nail in the coffin of the rather stupid claim that nuclear energy is more dangerous than say, the coal for which anti-environmental, anti-nuclear morons are so ready to apologize and make excuses. It seems that these people have never heard of global climate change.

I know a coal apologist, for instance, who is currently involved in a dubious campaign to argue that tritium is a serious contaminant resulting from nuclear reactors. These posts include rather absurd claims, for instance, that the experience of a person standing outside of a nuclear reactor, as many millions of people have done, is the same as that of a rat who is either injected or drinks tritium.

I love this stuff. It couldn't be any better.

As I will demonstrate in a series of posts in this thread the risks associated with tritium are vanishingly small compared with even the uranium emission risk of coal fired power plants, whether one is looking at the (very small) radiological risks associated with uranium or its much higher chemotoxicity. I find this very amusing, in a way, because I am always the first to jump on people who carry on about DU, depleted uranium, not the website, and how Iraq is a "nuclear war," in so doing trivializing both the valid reason for opposing war and further trivializing what real nuclear war actually is. This too is nonsense. Generally the same group argues for coal as opposed to nuclear energy (although the use of nuclear energy destroys uranium), though coal probably accounts for much greater ingestion of uranium - and not even depleted uranium - than tank shells.

Some people think that radiation risk is preternaturally more dangerous than any other risk mostly because they don't understand a fucking thing about radiation in particular or risk or science in general. Fear is ignorance. They rather persistently insist that because they are paranoid about radiation, the mere mention of any risk from radiation is the same as demonstrating that coal, gas, and oil plants are preferable to nuclear plants. This is not just dumb. It is wrong, morally wrong.

The world agrees, I think, with me. The plans for new planned nuclear plants are picking up at an accelerating pace. The world, if not the bratty puerile members of Greenpeace, gets it. Most people are not scared shitless by so called "nuclear waste." Most people are scared shitless by global climate change.

The point of my participation in this thread is to further obviate the truth: There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[struggle4progress]

27. The 10E-4 probability of tertiary H3 production I cited will provide ..

.. the correct order of magnitude figures for reactor H3 production.

Your earlier claim, that the only reaction of interest is successive neutron captures by proton and deuteron, is simply nonsense.

[NNadir]

29. Really? Maybe you would like to take over the discussion of the

production-destruction equation? Aren't you the person who told us that CANDU reactors produce lots of tritium as opposed to other reactors, or am I only imagining that?

Why would a CANDU reactor produce more tritium than a PWR?

Show us a calculation to back up your claim.

Why is the world supply of commercial tritium found mostly in Canada?

What is the isotopic evolution of moderating water in the core of a PWR reactor? Give us your expert opinion.

If you take over this discussion of radioequilibrium of course, you will have to demonstrate risk at the end of it. If for instance, each nuclear reactor produced 68 million curies of tritium, all of it from fission and not induction, we would have to demonstrate a health consequence, including incorporation of that 68 million curies in specific persons in measurable concentrations associated with measurable health consequences.

Part of this will involve showing the high specific activity of life forms on earth attributable to tritium, not just some laboratory rat fed tritium as part of some dubious demonstration - but all life forms in general, including the operators of nuclear power plants and the citizens of all persons living near nuclear power plants.

Come on, do it. I love this stuff. It couldn't be any better.

The matter of tritium and risk is an important demonstration of the fear and ignorance of anti-environmental anti-nuclear radiation paranoids. It really doesn't matter, of course, if tritium is made at the edges of the atomsphere, or from spallation reactions, or from capture reactions. The question is, can we actually demonstrate the existence of a person who has been injured by tritium? What is the frequency of such persons and how does that frequency compare with persons who are injured by, say, air pollution, or global climate change induced famines?

We can nitpick all day about trivial technical issues related to the trivial risk of tritium in an effort to change the subject, but the outcome of the discussion is the same. Where are the tritiated dead? Where are the highly tritiated people in general?

Let's cut to the chase then. Tritium, like all radioactive substances, is easy to detect. Nuclear power plant workers walk through radiation detectors every day. So presumably they are all dead from tritium, no?

Or does nuclear mysticism always come down to the same game. It's radioactive! I'm scared! I'm terrified! Nuclear! Nuclear! Terrorism! Scare! Scare! Scare!

How come you ain't scared of global climate change? :sarcasm:

Sorry coal boy, I'm unimpressed.

Of course, even if a tritium fearing moron were able to demonstrate (and we have not even begun to touch the subject of deposited energy from uranium and daughter decays as opposed to tritium decays - we'll get to that after we cover radioequilibrium) had harmed someone, the moron in question would still be required to prove that the number of persons harmed will be on the same order of magnitude as those injured by global climate change, or mercury toxicity, or acid leaching of other heavy metals including natural radioactive metals like uranium.

Otherwise the moron in question would only be obviating the truth: There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[struggle4progress]

30. Yawn. eom

[NNadir]

39. A pretty telling answer, I think.

I think you surely slept throug science classes in high school and never took another again.

[NNadir]

17. Now, very briefly, let's look at the radioactive decay law.

It is well known, obvious really, that the number of radioactive decays that one can observe is proportional to the amount of radioactive material that one has. Radioactive decay is measured in two units named after French scientists: The Bequerel, Beq, which is an exact count of the number of atoms that actually decay in a period of 1 second, and the Curie, Ci, which is exactly 3.7 X 10^10 Beq. A Curie is roughly equivalent to the number of decays that take place in one gram of radium-226, the element first isolated by Madame Curie from ton quantities of pitchblende, a uranium ore that in her case, was found in that portion of the Austrian-Hungarian empire that was to become part of the Czech Republic.

The number of radioactive decays that one experiences in different elements is not the same. Tritium, which has a half-life of 12.33 years decays much faster than radium-226, which has a half-life of 1600 years. The half-life is of course, the time required for exactly one half of the atoms of a particular radioactive isotope to decay to be some other element, which may or may not be radioactive itself. For instance, as I noted elsewhere, the world supply of (non-weapons) tritium is 18.5 kg. If one were to possess this tritium and neither add to the supply nor sell any of it to researchers using it for various types of tracer studies, after 12.33 years, only 9.25 kg would remain. Another 9.25 kg would have spontaneously converted into helium-3, which is not radioactive, but merely extremely interesting. Using the rules available to anyone who has taken and understood high school chemistry, we can actually calculate how many atoms of tritium have decayed to become helium 3. The atomic mass of tritium is 3.0160493 grams per mole. 9.25 kg = 9250 grams = 9250/3.01 moles = 3070 moles, where I have carried 3 significant figures. Avogadro's number is a constant that gives the number of atoms per mole, 6.02 X 10^23, meaning that meaning that one would have been able to observe the nuclear decay of 1.85 X 10^27 atoms.

If one, were on the other hand, a researcher who had been provided with a 2 grams of tritium for some purpose, following the above calculation, after 12.33 years one would have 1 gram left, and one would have observed only 2.00 X 10^23 decays.

Thus we see that the number of decays is proportional to the amount of material we have in the first place. This is a statement in words of the mathematical law of physics known as the radioactive decay law.

Mathematically, the radioactive decay law is expressed as a differential equation. We say that the number of decays, dN, (dN is a change in the number of atoms we have) that we experience in an in an arbitrarily small period of time, dt, is proportional to the number of radioactive atoms we have at any point in time, N. Thus the law is written dN = -kN dt where k is a proportionality constant that depends on the particular radioactive number in question. The minus sign reflects the fact that we will always after the passage of time have fewer atoms of the radioactive substance than we had at the outset. If we rearrange this equation to separate variables we have dN/N = -k dt. Integrating we have ln(N) = -kt + C. Using the usual rules of calculus with respect to initial conditions and eliminating the logarithms, this law can be rewritten as N(t) = No*exp(-kt) where N(t) is the number of atoms of radioactive material present at time t, No (an equation editor would have the zero as a subscript) is the number of atoms at time zero, and the exp() refers to the exponential function.

There is a related equation that is important in nuclear reactors that is called the production-destruction equation. For many nuclei involved in nuclear reactors it is generally somewhat more complex and involves numerical computation using sophisticated (but readily available) computational algorithms. Happily, though for the simple case of tritium production the equation can be greatly simplified to give a relatively simple differential equation, so simple that one can, again, simply gloss over the mathematics, if one wishes, to understand the result and its consequences.

Simple? (Have I simply used the word "simply" enough?)

I will cover the production-destruction equation in my next post, to enable interested parties to understand how radioequilibrium works, an important concept in understanding the major difference between the radioactivity released by coal plants, and the radioactivity released by nuclear plants - and why the former is much worse and much more dangerous.

This will help us to understand an important truth: There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[hunter]

18. Hello NNadir, you have 6,000 posts!

http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=105&topic_id=4535843&mesg_id=4535843

:hi:

[NNadir]

19. So I do. Thanks for pointing that out to me. I didn't realize that. n/t

[NNadir]

20. Addendum: Calculating the constant k.

I neglected, in my previous post, to show how the contant k in the radioactive decay law is calculated from the half-life.

(Note that many texts refer to this constant using the greek letter lamda, which is not available in the editor here. This is particularly true of nuclear engineering texts, because k, in the context of nuclear engineering, is the normal symbol for an important parameter known as the multiplication constant. Some undergraduate physics texts use k for the nuclear decay constant, which is why I have chosen it here.)

k, as used in the radioactive decay law, can be found from the half life in the following way: Recall the radioactive decay law from above: N = No*exp(-kt). After the passage of one half-life N = 1/2 No by definition. Thus we have 1/2 = exp(-kh) where h is the half-life of the isotope. Taking the natural logarithm of both sides of the equation, and dividing both sides by h we see that k = ln(2)/h. Thus approximately k = 0.693/h. For those with no mathematical background, ln(1/2) = -ln(2).

[struggle4progress]

21. The genetic and late somatic effects of chronic tritium ingestion in mice

Curr Top Radiat Res Q. 1978 Jan;12(1-4):212-24
The long term somatic and genetic effects of chronic tritium (3H) ingestion have been measured in mice. Second generation animals, who with their parents were maintained on drinking water containing 3 muCi/ml of HTO, have been bred and the number of dominant lethal mutations measured. The increase in dominant lethal mutations in treated animals as compared to tap water controls is significant at the 1% level ...
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=639548&dopt=Abstract

[NNadir]

23. I have committed to read all posts in this thread, no matter how tiresome

and dull.

This note is to acknowledge that I have kept my promise.

For now I have no other comment.

[struggle4progress]

25. Analyses of a Cohort of Workers Exposed to Low Doses of Low-LET Ionizing .

.. Radiation

William Hazelton, Suresh H. Moolgavkar
Fred Hutchinson Cancer Research Center

We are currently analyzing lung cancer incidence and mortality in a Canadian national dose registry (CNDR) cohort using the biologically based two-stage clonal expansion model to see if we can ascertain possible effects of protracted low-dose low linear-energy-transfer (low-LET) ionizing radiation exposure. We have extended our analyses to include models with more than two stages, and will soon broaden the scope of this study to include analysis of female breast cancer incidence and mortality in this cohort ...

Our initial analyses looked at lung cancer incidence in the 95,439 males in the cohort. We found an exposure-response relationship between lung cancer incidence and exposure to gamma radiation that is highly significant. Tritium exposures are generally small in comparison to gamma exposures, but also appeared significant. However, individuals with tritium exposure are frequently flagged for possible neutron exposure. Both gamma and tritium exposure appear to influence lung carcinogenesis by making a highly significant but small dose-dependent increase in the net cell proliferation rate, and also a highly significant small increase in the second mutation rate ...

http://lowdose.tricity.wsu.edu/2001mtg/abstracts/hazelton.htm

[NNadir]

31. According to this link, if true, 3 people in 20 years got cancer from

tritium...

Of course in a study of 95,439 males, there is some room for statistical error in this stunning conclusion.

Note that there is no remote attempt to study how many people died from lung cancer from coal powered plants in 20 years. That would be stupid wouldn't it?

Any idea how many people died from coal fired power plants in that period? Any idea how many people suffered from global climate change in that period? Any comment on how many more people would have died from global climate change if all nuclear power plants would have been shut to satisfy the radiation paranoid notions contained in this precious bit of scare mongering and supposition?

Or is it more "nuclear exceptionalism?"

Of course it is. The conceit of immoral anti-environmental anti-nuclear morons is that there is risk free energy. With this notion they advocate killing people.

Thirteen men died this week mining coal in the United States. Last year thousands of other people worldwide died in the same activity. Many more were killed by air pollution and many, many, more will die in a very short period from global climate change's consequences. The water supplies of vast numbers of people are about to be destroyed, coastal areas ravaged, entire nations evacuated. 15 men were killed, and 100 people injured in an oil refining explosion, early last year. Who remembers? Only me. 28 men died on an ethanol tanker that blew up last year. Who remembers? Only me.

Natural gas explosions killed 233 people and injured over 9000 in China on December 29, 2003: http://www.asianresearch.org/articles/1806.html

Yeah, I can google too.

In fact, according to this googled link, reporting on a 1994 study, 50,000 to 100,000 Americans have die each year from air pollution: http://www.cancer.org/docroot/nws/content/nws_1_1x_air_pollution_linked_to_deaths_from_lung_cancer.asp

OK lets do some moral math. The excitement here is about 3 claimed excess deaths from tritium (OH MY GOD TRITIUM) over 20 years. That's one death every every 0.15 years for radiation workers, not mind you, deaths among the general public. So, ignoring non integers, if 50,000 people die each year from air pollution and 0.15 people die each year from tritium we have 50,000 - 0.15 = 50,000 people who lost their lives, or if you are a big trivializing person, 49,999.85 lives lost.

Here we have a number for the number of people who are killed each year because of opposition to nuclear power. What a victory for all human kind the opposition to nuclear power is!

Does any anti-environmental anti-nuclear radical obsessive care about these any of these non-nuclear deaths? No, what is important to them is three alleged tritium deaths over 20 years. How triumphally these deaths are noted! (Note that this googled report contains no references and is unpublished except for an internet link.) Here is what anti-environmental anti-nuclear activists are: They are moral frauds.

There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[struggle4progress]

32. Not what the link says. The authors use a multiple mutation model ..

.. for malignancy induction, which means most cancers have not just one but several causes. They fit this model to a cohort for which exposure data allegedly exists and detect dose-dependent effects of tritium at both stages of their lung-cancer model. If tritium affected only one stage, malignancy induction would always depend on another mutagen.

Notice that hundred of people in the cohort died from lung-cancers, the cause or causes of which are not identified. Assuming that a similar model applies, these individuals also experienced successive mutations, first to initiate and then to promote the malignancy. Either or both of these mutations might have been chemical, one might have been chemical and the other gamma/tritium, etc. But since the authors do not appear to have data to match chemical exposures, any effects (for example) of one gamma/tritium mutation on a population which otherwise experienced chemical mutation (either before or after) will be masked by the uncontrolled noise of the chemical exposures.

Note that the link considers on lung-cancer from gamma/tritium. Other radiological hazards exist, and so do other cancers.

The authors of the link, incidently, have widely published in the peer-reviewed literature.

[NNadir]

33. So the point of the words "might" and the authors don't have data...

In the context of a discussion of tritium it means what?

Oh, I know, that the deaths over a twenty year period from what might be radiation is the same as 1/5000ths of the number of deaths from air pollution in one year?

Of course, I hold a very low opinion of the intellect of anti-environmental anti-nuclear retards because, well for one thing, they cannot get it through their pathetic heads that proving some cases of risk associated with a nuclear operation is not the same thing as proving that there is any safer operation than nuclear power.

There clearly is not. We know this when we consider expectation values. For instance, suppose, as is clearly not the case, that the risk to 100,000, people (radiation workers) is that 100 of them will ultimately die of cancer - not instantly of course, but over a course of many years. The expectation value is 100. (100,000*100/100000) How does this risk compare with the global climate risk that Bangladesh, with hundreds of millions of people will have its agricultural fields destroyed by salt water from rising seas. Suppose that the risk is the same and the dunderhead claim about radiation induced cancers in radiation workers, 0.01%. Since 100,000,000 people might be killed as the result of these famines, the expectation value is 10,000. Thus the risk from global climate change as anyone but a moral idiot can tell is 100 times greater.

Of course the consequences of global climate change are not already limited to Bangladesh, nor are the risks of global climate change really a 1 in 10,000 shot. Global climate change and fatal impacts to human beings is already a certainty. It is not the subject of some statistical analysis. Already the damage created by this intractable problem that is occurring, in spite of the indifference of Greenpeace middle class cretins, now.

Or is it the case that the dubious opinion of the authors of any dunderhead radiation link provided by an anti-environmental anti-nuclear air head in a meandering dopey discussion of the non-problem of tritium somehow proves that global climate change is not occurring?

I have promised to read every post in this thread no matter how dumb, even though I struggle with making progress on the notion of understanding how much dumber posts can actually get. There is no limit to the bottom, apparently, with repetition of the pitiable notion that nuclear energy must be risk free while the risk of every other serious alternative should be ignored.

This of course, as I frequently point out is not indicative of thinking. It is indicative or religious posturing, religious posturing being something I personally morally detest.

I think I'll get back to discussing something called science. As I often state, bizarre religions about things like tritium make me morally ill.

Before I go back to reality however, I think it is worth linking to this graph which gives "tritium units," a tritium unit being equal to one atom of tritium being found in every 10^18 hydrogen atoms found in water or other hydrogen compounds. Here it is:



http://www.science.uottawa.ca/~eih/ch7/7tritium.htm

Here is a graph of the production of nuclear energy world wide:



http://www.world-nuclear.org/info/inf01.htm

Thus we see that while the production of commercial nuclear energy was rising dramatically, the atmospheric burden for tritium was falling. Most of us, myself included, have lived our lives with a much higher burden of tritium than now exists, since tritium concentrations are still falling. In fact the peak loading of tritium in the atmosphere occurred while commercial nuclear power was still largely a curiosity as opposed to the industrial operation it is today.

So the claim that tritium production represents a increased risk from nuclear power is like every other bit of dunderhead irrelevancy raised by coal apologists -fraudulent. This can be seen by measurement, measurement being the starting point for science..

The fact is that anti-nuclear people cannot offer us anything but a choice between poverty (which leads, by the way to environmental degradation) and more fossil fuel use. Oh, they cite things like "wind" solar, yabber, yabber, yabber, but they do not produce energy. http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=37086&mesg_id=37086 The biggest wind energy they actually demonstrate is that which turns a few turbines here and there. It is, instead, the nearly useless hot air escaping from their foetid and pixilated mouthes. In fact is only one industrial scale form of energy that can be further safely and immediately scaled without completely destroying that atmosphere. That energy is nuclear energy.

The point of the subject changing and diversion of attention to the mechanism of tritium formation to blabber about the authors of this blurb and that blurb, resume reading, exercise of the list of logical fallacies from "abstraction," through "appeal to authority" to "guilt by association to "wishful thinking", (complete list a to z: www.fallacyfiles.org) does not materially effect in any way a change this truth:

There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[struggle4progress]

35. Global tritium inventories would equilibrate at near bomb-era levels ..

.. in the global nuclear economy with reprocessing that you advocate, assuming that we avoided the heavy water reactors popular in Canada. If we, instead, used such reactors the steady-state values would be several orders of magnitude above the bomb-era levels.

And it is dishonest to contemplate the effects of this under an assumption that radionuclides are instantly equidistributed throughout the entire atmosphere and ocean: what will happen, instead, is the production of local hotspots, such as have existed near the Sellafield reprocessing plant where children regularly "enjoy" radiogenic leukemias.

[Dead_Parrot]

36. Incidentally, S4P...,

Are you the one with the non-nuclear, non-fossil-fuel energy plan that's workable in a decade or so?
Or are you another passer-by who thinks a thousand Chinese deaths from fossil pollution and a million global warming refugees in Bangladesh is a fair price for saving a dozen US lives from a nuclear mishap?

Just asking.

[struggle4progress]

40. No, DP, I'm the one the high school officials threatened to suspend ..

.. thirty years ago for passing out pro-recycling fliers, since everybody in the rightwing town knew communists were pushing recycling as a way of destroying US industry. I'm the one who actually has some friends from Bangladesh and from China and who spent some time in a small shack in Nanty Glo with a coal miner dying of black lung. I'm the one who's actually been threatened with a SLAPP suit by a polluter after I filed some comments on their mercury emissions with the state regulators. I'm the one who has actually gone to public hearings to complain about lack of enforcement of air quality permits. I'm the one who bought a house close to work and bought the most gas-efficient automobile I could afford to reduce the emissions from my own daily life. I'm the one who's actually taken personal leave days from work to drive to DC and lobby on Capitol Hill.

Grow up.

[Dead_Parrot]

42. So why the histrionics?

You know what fossil fuels are doing to us and the enviroment. You know what the alternative is. What's your suggestion?

[NNadir]

37. Oh really. Is the quality of your claim about Sellafield the same as

the quality of the rest of your arguments?

Here is a fact that you do not explain: Nuclear power increased, the tritium red herring went down.

Tough shit. It's DATA.

You are doing "intelligent design," with typical intelligent design type red herrings.

[struggle4progress]

38. Sophomoric argument. Ya really oughta know the tritium peak ..

.. was from atmospheric nuclear weapons testing. I already indicated this.

[NNadir]

41. Understanding from where tritium comes, global sources revealed.

Apparently when one sleeps through science classes, one don't learn very much.

To repeat: tritium levels have been falling continuously since 1963, while nuclear power production has been rising by 50 fold. One doesn't even know how to read to figure that out. One can merely look at the pictures.

It's data. Tough shit.

The claim represented by the anti-environmental anti-nuclear crowd is that nuclear power is risky because of tritium. But tritium from nuclear power plants is trivial even next to natural sources as shown. The red herring argument involved in raising tritium at all - and it is irrelevant in a rational discussion of the magnitude of risk - implies that tritium release is a major problem with nuclear power, but the person raising it appear to have zero concept of scale or source of tritium.

If I had were teaching a high school sophomore and he made a grand (irrelevant) speech about tritium in the context of nuclear power, I would give him or her a very poor grade indeed. I would note that such a person needs to aspire to the sophomoric level, that they have not, in fact, reached it.

I love this stuff. It doesn't get any better than this.

Read it and weep, coal boys and girls:

4.2.2 Sources of Tritium Release in the Environment

The major natural source of tritium is cosmic ray reactions in the upper atmosphere. A minor portion of the annual natural tritium production comes from the earth’s crust, a result of neutron capture reactions by 6Li in rocks. The steady-state global inventory of tritium from all natural sources is estimated to be in the range of 1 to 1.3 10^18 Bq . Based on a 12.3 year half-life, this inventory corresponds to an annual production of 0.062 X 10^18 Bq/y. Measurements taken before open-air nuclear testing began (before 1950) indicate that HTO in natural waters in the U.S. ranged from 0.14-7.9 Bq/L for Chicago rain water, 0.16-0.21 Bq/L for Lake Michigan water, and 0.30-0.77 Bq/L for the Mississippi .

Anthropogenic sources of tritium in recent decades have far exceeded natural sources. Atmospheric nuclear weapons tests in the 1950s and 1960s are estimated to have produced from 185 to 240 X 10^18 Bq of tritium . It is estimated that, in the 1990’s, the legacy of the nuclear weapons test of the 1950’s and 1960’s is an additional 52 X 10^18 Bq of tritium in the current global inventory .

Normal releases of tritium from nuclear facilities are estimated to produce 0.02 X 10^18 Bq/y and off-normal releases an additional 0.001 10^18 Bq/y with a resultant steady-state buildup of 0.4 X 10^18 Bq globally . Based on total previous levels of production, the legacy of luminous products (such as watch dials) is estimated to currently release 0.4 X 10^18 Bq/y with a resultant steady-state build up of 7.4 X 10^18 Bq globally . However, the luminous-dial source is expected to decrease in time.

The combined natural and anthropogenic emissions of tritium result in a current global inventory of approximately 53 X 10^18 Bq, which is about 50 times greater than tritium levels due to natural sources alone. However, much of this tritium is deposited in the deep ocean where it is unavailable to the circulating waters of the Earth.

(I have edited this excerpt to restore the scientific notation removed by cutting and pasting into this editor. The bold is also mine.)

http://www.lbl.gov/ehs/esg/tritium/tritium/TritCh4.html

Thus the world has long existed, billions of years in fact, with higher tritium levels than are attributable to nuclear power or ever will be attributable to nuclear power. Maybe they don't teach this is the Greenpeace religion and radiological mysticism but everybody on earth didn't die from tritium when a pulse of tritium raised the concentration by nearly 1000 fold in 1963.

(Wouldn't it be fun to wear a tritiated watch to a Greenpeace meeting? http://www.chronomaster.co.uk/orfina_watches.htm)

Of course, we now have a prediction that tritium will rise to unsafe levels if nuclear recycling grows in popularity. Anti-environmental anti-nuclear paranoids are very good at predicting things. They predict all day long. Note that predicting is not the same as predicting accurately but hey, who's counting. Oh, I am. They predicted that the nuclear industry would wither and die for economic reasons, showing that they know about as much about economics as they know of physics. They also predicted (and still predict) a solar nirvana. They predicted regular fatal nuclear accidents. They predicted that nuclear power plant construction would stop. And so on...

But tritium is irrelevant to the question of saving humanity and all other living things. Clearly if we wish to prevent tritium from existing, we must boil off the world's atmosphere. This is, of course, exactly what anti-environmental anti-nuclear paranoid nut cases are trying to do as they ignore global climate change, but I am doing my level best to stop this crime against the earth.

The entire anti-environmental anti-nuclear argument is an exercise in avoiding the subject, which is risk. A fraud can use the word "Sellafield" and cancer in a sentence one thousand times and not ever demonstrate that lives will not be saved by the use of nuclear power. This is because all energy involves risk.

The energy risk to all humankind is the risk of having no energy. The risk of having no energy is the same as the risk of poverty, which is something to which the middle class moral retards at Greenpeace are completely indifferent. They will cry crocodile tears about alleged babies here and there who they say were killed by radiation, of this type or that type, misinterpret the scientific literature ad nauseum, but not one of them will ever give a rat's ass for the billions of people who die, suffering horribly, from poverty. And let's be clear: Global climate change will increase poverty. Moreover, poverty is extremely detrimental to the environment, as any one who has been to say, India, knows, since people who are trying desperately only to survive are not going to focus on good stewardship of the earth. Thus the insistence that cheap energy (which includes nuclear energy) be replaced by the expensive fantasies of westerners is well, genocide.

A million Sellafields, assuming that there really even is a person who has really been injured by its normal operations, will not produce risk comparable to poverty.

But again, even if tritium does kill a few people on the planet every couple of decades, it proves exactly zero, since millions, if not billions are at risk from energy technology, notably fossil fuels. Therefore all the weeping about tritium (or whatever red herring) does absolutely nothing to void this truth:

There is no such thing as risk free energy. There is only risk minimized energy. That energy is nuclear energy.

[NNadir]

34. Neutron fluxes in non-fissionable matter, more production-destruction eq'n

Although I have allowed myself to have been diverted by heckling from the red (herring squad http://www.fallacyfiles.org/redherrf.html) - I can't resist showing them up for exactly how little science they know - I have promised to further show how radioactive equilibrium works as part of a demonstration that the radioactivity released by coal plants is more serious than the radioactivity of nuclear plants.

Because my opponents are as rhetorically weak as they are scientifically weak, because they can't think, I will need to remind all readers in advance that the question of radioactivity from coal plants is basically trivial - the real risks of coal fired plants that swamp their greater radiological risk with respect to nuclear plants are in order of importance: Global climate change, chemotoxicity and accidents. The chemotoxicity may be further divided into effects such as air pollution, including carcinogenic particulate matter, nitrogen oxides, carbon monoxide, acid rain, acid run-off into streams and rivers, heavy metals (including but certainly not limited to uranium and thorium) disposal of toxic ash (amounting to many millions of metric tons per year.

Previously I have discussed some parameters that appear in the production destruction equation; the number of atoms present, the macroscopic and microscopic cross section, and the radioactive decay constant. The relevant previous posts in this thread are posts #10, #14, #17 and #22.

I have defined the decay law constant as k. (The greek letter lamda is often used in texts.)

I have defined the microscopic nuclear cross section as s. (The lower case greek letter sigma is often used in texts.)

I have defined the macroscopic nuclear cross section S. (The upper case greek letter sigma is used in most nuclear engineering texts for this variable.)

I have touched upon, but not explicitly stated another parameter that appears in the equation, the fission yield. Typically only fission yields of radionuclides that appear in quantities of greater than 1% and have large cross sections for nuclear interactions are of any importance. The fission yields for fission products uranium and plutonium are tabulated to five or six significant figures at various neutron energies.

The fission yield for a particular fission product is designated by the greek letter gamma. Here I will use the letter g, because of the editor.

From a radiological perspective almost all of them are trivial as they typically remain in the matrix of the fuel itself - although occasionally trivial quantities may leak into the atmosphere, particularly the few fission products that are volatile. (Volatile fission products such as krypton-85 also are released during fuel reprocessing, but again the effect is trivial.)

I have also touched upon what a neutron flux is in post 22. A neutron flux is the number of neutrons passing through a unit of area in a unit of time. A typical neutron flux in a nuclear reactor is on the order of 10^12 to 10^13 neutrons per square centimeter per second.

The neutron flux is typically designated by the greek letter Iota. I will use the letter i.

When neutrons pass through matter, a small number of them are always absorbed unless the matter in question is helium-4, which has a capture cross section of zero: It "is invisible" to neutrons "seeking" to be absorbed. (Helium only scatters neutrons; it does not absorb them.) How many neutrons are absorbed depends, again, on the capture cross section, and the density of atoms in the unit of volume through which the neutrons pass. Since the cross section of different types of atoms changes with neutron speed, the matter can be quite complex, and requires description through equations like that called the Breit-Wigner equation. However we will simplify it and assume constant, or "average" neutron speeds.

In a layer of arbitrarily small thickness dx (x being distance) with fixed area through which a neutron flux, i, passes, some of the neutrons will be captured, depending on the number of atoms present and their capture cross sections and the flux will change by some small amount di where the d is the differential symbol used in calculus. We have di/i = sN dx which integrates to give i = io* exp(-sNx). io here (read i sub zero) refers to initial flux.

The density of water is around 1.0 grams per milliliter, meaning each gram, according to the laws described in high school chemistry a 1/18 moles of water. Multiplying by Avogadro's constant we see that cubic centimeter of water (aka a milliliter) contains about 3.34 X 10^22 atoms.

Now we have everything we need to know. In post #33 I have shown the data without any appeal to theory whatsoever shows that the (largely trivial) concentration of the radioisotope tritium in the environment has been falling steadily since 1963 even while the production of nuclear power has increased by a factor of well more than 50 times. Elsewhere someone has asserted that large nuclear reactors add tritium to the environment. (This is actually true.) How then is it possible that the concentration has been falling while a major (relatively) new technology producing it has been growing?

I will write down now the production destruction equation, which is a differential equation. Consider a particular radioisotope, b, and a nucleus that is created by capture from a nucleus, a, that is exactly one mass unit lighter, ie one that captures a neutron to from it. We have:

dn(b)/dt = gSi + summation {k(a ->b) + s(a->b)n(a)-(k(b)+s(b)s)n(b)}

(The a and b in parentheses should be read as subscripts.)

I will come back and attempt to explain what the fuck this means.

[Dead_Parrot]

8. CO2 is my main worry

From a purely self-centered point of view, that is. If I lived in central Beijing I'd be more worried about particulate pollution, but I'm lucky. CO2 levels are now around the 370 ppm mark, the highest they've been since a walking monkey discovered some interesting facts about flint: But half the world's environmentalists are sitting around saying we should wait for a magical solution to energy rather than use a perfectly good one we already have, simply because they don't understand it.

:banghead:

Hey ho...

The avatar's one of the DU stock ones - recycle.gif, IIRC.

[philb]

28. some coal is very radioactive: I'm told the coal used at the Smith Plant

in Panama City, Fl is so radioactive that most of St Andrews Bay, where the plant is located,
has become so radioactive that if you take a geiger counter in a boat across the bay it goes off
big time with significant radiation readings, and that much of the seafood is also radioactive.

[NNadir]

4. Has a dirty bomb plot ever been discovered anywhere at any time?

Did someone prove that Padilla, an uneducated Moslem convert ever even knew what radioactivity actually was?

I am very concerned with the fact that Santa Claus comes into to the US every year without being inspected. After all, living up their in the artic, he has access to the old Soviet Nova Zembla nuclear test site.

I hate to break it to anyone, but there are no nuclear terrorists, unless you count governments.

[ddeclue]

12. The so called "dirty bomb" or RDD

Radiological Dispersion Device is for all intents and purposes not really significantly more deadly than the explosives that were used to disperse the radioactive materials. The whole concept relies on the public's fear and ignorance regarding radiation and their confusion between a real nuclear fission or thermonuclear fission-fusion device and a simple RDD to cause an unjustified panic.

This is the kind of Bush Administration "fear talking point" of the day that they try to use to control and manipulate the public.

And Padilla finally was charged with various offenses but not one related to building an RDD.