Subcritical Thorium Reactors: Dr. Rubbia’s Really Bad Idea

The Telegraph (hattip Insty) turned the hype level to max in a recent article about the potential of thorium reactors.  According to the headline, “Obama could kill fossil fuels overnight with a nuclear dash for thorium.”  Against all odds, this is to happen in three to five years with a “new Manhattan Project,” and a “silver bullet” in the form of a new generation of thorium reactors.  The author is so vague about the technologies he’s describing that it’s hard to avoid the conclusion that he simply doesn’t know what he’s talking about, and couldn’t be bothered to spend a few minutes with Google to find out.  I’ll try to translate.

It’s claimed that thorium “eats its own waste.”  In fact, thorium is very promising as a future source of energy, but this is nonsense.  Apparently it’s based on the fact that certain types of thorium reactors actually could burn their own fuel material, as well as plutonium scavenged from conventional reactor waste and other transuranics, much more completely than alternative designs.  This is certainly an advantage, but the fission products (lighter elements left over from the splitting of uranium and plutonium) would still be highly radioactive, and would certainly qualify as waste.  Such claims are so obviously spurious that they play into the hands of opponents of nuclear power.

It is also claimed that “all (thorium) is potentially usable as fuel, compared to just 0.7% for uranium.”  In fact, thorium is not a fissile material, meaning that, unlike uranium 235 (U235), which is the 0.7% of natural uranium the author is referring to, it cannot sustain a nuclear chain reaction on its own.  It must first be converted to a lighter isotope of uranium, U233, which is fissile.  In fact, the U238 that makes up most of the rest of the leftover 99.3% percent of natural uranium is “potentially usable as fuel” in that sense as well, by conversion to plutonium 239, also a fissile material.

The author is vague about exactly what kind of reactors he is referring to, lumping Dr. Carlo Rubbia’s subcritical design, which depends on a proton accelerator to provide enough neutrons to keep the fission process going, and molten fluoride salt reactors, which do not necessarily require such an accelerator.  He claims that, “Thorium-fluoride reactors can operate at atmospheric temperature,” which they certainly could not if the goal were to generate electric power.  I suspect that what he means here is that, unlike plutonium breeders, which require a high energy neutron spectrum to produce more fuel than they consume, thorium breeders could potentially use “thermal” neutrons that have been slowed to the point that their average energy, when converted to a “temperature,” would be much closer to that of the other material in the reactor core. 

In any case, the design he seems to be so excited about is Dr. Rubbia’s “energy amplifier,” which, as noted above, would be subcritical, requiring a powerful, high current proton accelerator to keep the fission process going.  It would do this via spallation, a process in which a copious source of the neutrons required to keep the reaction going would be provided via interaction of the protons with heavy nuclei such as lead, or thorium itself.  This is the process used to produce neutrons at the Oak Ridge Spallation Neutron Source.  Such reactors could easily be “turned off” by simply shutting down the source of neutrons.  However, the idea that they would be inherently “safer” is dangerously inaccurate.  In fact, they would be an ideal path to covert acquisition of nuclear weapons.  Thorium reactors work by transmuting thorium into U233, which is the isotope that fissions to produce the lion’s share of the energy.  It is also an isotope that, like U235 and Pu239, can be used to make nuclear bombs. 

The article downplays this risk as follows:

After the Manhattan Project, US physicists in the late 1940s were tempted by thorium for use in civil reactors. It has a higher neutron yield per neutron absorbed. It does not require isotope separation, a big cost saving. But by then America needed the plutonium residue from uranium to build bombs.

“They were really going after the weapons,” said Professor Egil Lillestol, a world authority on the thorium fuel-cycle at CERN. “It is almost impossible make nuclear weapons out of thorium because it is too difficult to handle. It wouldn’t be worth trying.” It emits too many high (energy) gamma rays.

What Lillestol is referring to is the fact that, in addition to U233, thorium reactors also produce a certain amount of U232, a highly radioactive isotope of uranium with a half life of 68.9 years whose decay does, indeed, release potentially deadly gamma rays.  It would be extremely difficult, if not impossible, to remove it from the U233, and, if enough of it were present, it would certainly complicate the task of building a bomb.  The key phrase here is “if enough of it were present.”  Thorium enthusiasts like Lillestol never seem to do the math.  In fact, as can be seen here, even conventional thorium breeders could be designed to produce U233 sufficiently free of U232 to allow workers to fabricate a weapon without serious danger of receiving a lethal dose of gamma rays.  However, large concentrations of highly radioactive fission products would make it very difficult to surreptitiously extract the uranium, and it would also be possible to mix the fuel material with natural or depleted uranium, reducing the isotopic concentration of U233 below that necessary to make a bomb.

With subcritical reactors of the type proposed by Rubbia, the problem of making a bomb gets a whole lot easier.  Rogue state actors, and even terrorists groups if we “succeed” in coming up with a sufficiently inexpensive design for high energy proton accelerators, could easily modify them to produce virtually pure U233, operating small facilities that it would be next to impossible for international monitors to detect.  There are two possible pathways for the production of U232 from thorium, both of which involve a reaction in which a neutron knocks two neutrons out of a heavy nucleus of Th232 or U233.  Those reactions can’t occur unless the initial neutron is carrying a lot of energy as can be seen in figure 8 of the article linked above, the threshold is around 6 million electron volts (MeV).  That means that, in order to produce virtually pure U233, all that’s necessary is to slow the incoming spallation neutrons below that energy.  That’s easily done.  Imagine two billiard balls on a table.  If you hit one as hard as you can at the other one, what happens when they collide?  If your aim was true, the first ball stops, transferring all its energy to the second one.  The same thing can be done with neutrons.  Pass the source neutrons through a layer of material full of light atoms such as paraffin or heavy water, and they will bounce off the light nuclei, losing energy in the process, until they eventually become “thermalized,” with virtually none of them having energies above 6 MeV.  If such low energy neutrons were then passed on to a subcritical core, they would produce U233 with almost no U232 contamination. 

It gets worse.  Unlike Pu239, U233 does not emit a lot of spontaneous neutrons.  That means it can be used to make a simple gun-type nuclear weapon with little fear that a stray neutron will cause it to fizzle before optimum criticality is reached.  And, by the way, a lot less of it would be needed than would be required for a similar weapon using U235, the fissile material in the bomb that destroyed Hiroshima. 

We’re quite capable of blowing ourselves up without Rubbia’s subcritical reactors.  Let’s not make it any easier than it already is.  Thorium reactors have many potential advantages over other potential sources of energy, including wind and solar.  However, if we’re going to do thorium, let’s do it right.

Cold Fusion and ARPA-E

According to it’s mission statement, the Advanced Research Project Agency – Energy (ARPA-E) is supposed to have more or less the same role within the Department of Energy as DARPA has for the Department of Defense. Quoting from the statement:

ARPA-E focuses exclusively on high risk, high payoff concepts – technologies promising genuine transformation in the ways we generate, store and utilize energy.

A statement of objectives on the ARPA-E website elaborates on this theme:

To focus on creative “out-of-the-box” transformational energy research that industry by itself cannot or will not support due to its high risk but where success would provide dramatic benefits for the nation.

Apparently the source selection guys who picked the first round of 37 projects to be funded by the new office never got the word. Read over the list, and you’ll find they have a distinctly incremental, chewed over flavor.   There are projects to train bacteria to produce biofuels, projects to make better batteries, projects to do a better job of removing CO2 from flue gas, etc.  All very interesting, but the chances that any of this stuff will be “transformational” are vanishingly small.  One project area that really is “high risk, high payoff” and potentially transformational is remarkable by its absence – cold fusion.

They’re taking a very dim view of the situation at the website of Cold Fusion Times. Their take:

Corrupt individuals within the US Patent Office and elsewhere continue to cover up cold fusion applications and other alternative energy inventions. ARPA-E and the DOE tricked scores of cold fusioneers to waste their time on proposals that went into the waste basket. For what reason? It is unethical that this has continued from the crash of the Exxon Valdez through the present disaster in the Gulf of Mexico. People around the world now believe that those involved in this coverup festering since 1989 should finally be held accountable.

I can understand the frustration, but that sort of hyperbole is both counterproductive and wrong.  I have seen no evidence that any of the individuals involved in the selection process are corrupt, or that there has been a “cover up.”  Orthodox energy scientists and bureaucrats would have nothing to “cover up,” because they simply don’t believe in cold fusion.  There was no attempt to “trick” anyone.

What we are really seeing at ARPA-E is hidebound conservatism, ignorance of what has been going on in the cold fusion community, and the time-honored reticence of bureaucrats in all ages to stick their necks out and risk ridicule by supporting anything unconventional.  I wouldn’t describe ARPA-E’s failure to fund a single one of the many cold fusion proposals it received, and its singularly bland choice of awards, as “corrupt” or ”trickery.”  A more appropriate adjective that comes to mind might be “pathetic.”  These people have utterly and completely failed to grasp exactly what it is their organization is supposed to be doing. 

“High risk, high payoff?”  Get real!  Let’s hope they do better next time.

2009 Colloquium on Lattice-Assisted Nuclear Reactions (LANR) at MIT

“Stealth” Fusion Progress

It didn’t take us long to master the destructive force of fusion, but taming it for more constructive applications, such as electricity production, has been harder than anyone imagined back in the day when a popular slogan was “online by ‘79.” Right, maybe in 2079 with any luck. We know of two scientifically feasible ways to get more energy out of fusion than it’s necessary to put in to ignite the fuel materials; magnetic fusion, as in ITER, or inertial confinement fusion (ICF) as at the National Ignition Facility (NIF). The problem with both approaches is not the science, but the engineering challenge of building reactors capable of generating electricity anywhere near as cheaply as the alternatives. At the moment, the chances that we will be able to do so any time in the foreseeable future seem remote.

If anyone around today lives to see the dawn of the era of fusion energy, it will probably be because some exceptionally clever researcher has hoodwinked Mother Nature and discovered how to finesse his way past the Coulomb barrier that usually keeps atomic nuclei too far apart to come within the range of the fusion-enabling strong force. Several promising candidates are already in the field, and one of them, Tri-Alpha Energy, has apparently managed to attract $50 million in private research funding. The company hasn’t revealed the nature of its approach, but it is apparently inspired by the work of Prof. Norman Rostoker of UC Irvine. One can get a broad hint from this paper co-authored by Rostoker and Tri-Alpha entitled, “Colliding Beam Fusion Reactors.” Rostoker is an emeritus professor who has been publishing papers since the 50’s, some co-authored with fusion superstars such as Nicholas Krall and Marshall Rosenbluth. Octogenarian physicists don’t often pull off such miracles, but you never know.

If he or someone else ever does manage to pull the fusion rabbit out of the hat, it would potentially put an end to our worries about energy for a very long time. It could also enable pure fusion weapons. Let’s keep our fingers crossed that it doesn’t.

Fusion Reaction

ITER: Throwing Good Money after Bad

According to the journal Nature, European nations hope to redirect more than €1 billion (US$1.25 billion) earmarked for research grants to make up a budget shortfall at the experimental ITER fusion reactor.  In an article that appeared in the July 7 issue, the editors note,

The proposal has alarmed scientists, who say that it will rob researchers of vital funds at a time when governments are planning to scale back domestic research budgets in response to the global economic downturn.

This is surely an understatement.  If I were a European scientist, I would be screaming bloody murder.  Like the International Space Station, ITER is a white elephant whose potential benefits will never come close to justifying the cost of building it.  It’s projected cost has tripled since it was estimated in 2001.  The fond hopes of the aging scientists who have devoted their careers to the pursuit of magnetic fusion energy will not be realized.  Like the International Space Station, ITER’s real effect will be to serve as a huge financial vacuum cleaner, soaking up billions in research money that could be much better spent elsewhere, including in the field of fusion energy research itself.

The problem with magnetic fusion, at least in the form represented by ITER, is that, while it is scientifically feasible, it will never be able to compete with alternative methods of producing electric power in terms of cost.  There are certainly hundreds of reactor design studies out there that claim the opposite, but, as the future will demonstrate if ITER is ever built, they are all wrong.  Among other things, the cost of a tritium economy has been grossly underestimated.  Tritium is a heavy form of hydrogen whose nucleus contains two neutrons in addition to the usual single proton.  Mixed with deuterium, another heavy isotope of hydrogen with a single extra neutron, it will be an essential fuel material in reactors such as ITER.  Deuterium occurs naturally, and is relatively common.  In other than trace amounts, tritium does not.  It must be produced artificially.  In order to produce the quantities necessary to keep a reactor like ITER running indefinitely, it will be necessary to surround the burning plasma with a thick layer of lithium.  Fast neutrons produced by fusion in the burning plasma can then produce the necessary tritium in nuclear reactions with this material. 

However, there is a slight problem.  Tritium is highly radioactive, with a half-life, the time it takes for half of any given quantity to undergo nuclear decay, of something over 12 years.  In spite of the fact that hydrogen is a notoriously slippery substance, passing with ease right through some types of metal, it will be necessary to control and contain kilograms of this material in a working magnetic fusion reactor.  In addition to its intrinsic radioactive hazard, tritium must also be carefully guarded to keep it from falling into the wrong hands.  For example, if terrorists were able to secure enough special nuclear material to build a nuclear bomb, they could potentially greatly increase its explosive yield by using tritium in the process known as boosting.  All this, not to mention the legal challenges that NIMBY’s are sure to mount to avoid living next to such an objectionable material, is unlikely to be cheap.

This and other potential show stoppers will insure that magnetic fusion reactors like ITER will never be able to compete economically.  Don’t believe me?  Wait and see.  It would be much better to use the increasingly scarce research dollars now being used to fund this particular white elephant on smaller projects, including fusion research projects, where it could do some real good.  Who knows.  They might even result in the discovery of a way to finesse Mother Nature after all and build fusion reactors that don’t need tritium and are economically competitive.

ITER

Tony Hayward sans Sackcloth and Ashes

The media in the U.S. have been making a big fuss about a sighting of BP CEO Tony Hayward at a yacht race. Apparently he’s supposed to be walking around in a circle hitting himself on the forehead with a board like the monks in Monty Python’s “Life of Brian.” I don’t blame him. He seemed to take the self-righteous hazing he endured at the hands of our grandstanding politicians with a good grace. Rep. Joe Barton, who apparently hasn’t learned that it’s a breach of protocall to refer to McCarthyism by its proper name if it’s for a good cause, actually dared to apologize for the public flogging. However, he quickly got back into line after a judicious jerk on his choke chain. As for Hayward, it seems to me that watching a yacht race is not really a mortal sin. He deserves a break, and hitting himself on the forehead with a board probably won’t significantly slow the flow of oil into the Gulf.

Nuclear Power: Sweden sees the Light

It’s been a long time coming, but the Swedish government has finally given the green light to construction of new nuclear power plants. The Guardian reported a ministerial decision to present a law to that effect to the Swedish parliament in February 2009. It’s taken a while for the legislative process to run its course, but Der Spiegel now reports that the new law has been approved. The restrictions on nuclear power in Sweden and several other European countries have never made much sense. They exist as a result of the now familiar efforts by “Greens” to evoke a fantasy world in which they are the noble saviors of humanity against the forces of evil, represented in this case by radioactive doom. Think “China Syndrome.” In the process of “saving” them, their environmental “gift” to the people of Europe has been to insure that any number of dirty coal-fired power plants would stay on line spewing massive amounts of cancer causing particulates and greenhouse gases into the atmosphere, while at the same time representing a substantially greater radioactive risk than nuclear plants of similar capacity.

It is unclear whether the new Swedish law will have concrete results. The situation there is similar in many respects to that in the United States where, in spite of the pro-nuclear stance of the Obama Administration, the ineptitude of government and the legal system and the short-sightedness of industry have combined to make the construction of new nuclear capacity prohibitively expensive. The “green light” also comes with many caveats. As Spiegel puts it,

The majority in favor was extremely thin, and came with any number of “whens” and “buts.” New reactors can only be built to replace one of the ten already in existence at the three Swedish nuclear plants at Ringhals, Oskarshamn, or Forsmark, and only then if one of them is taken off the net permanently. Government subsidies for private power companies are forbidden, and any approval of new construction will require demonstration of an increase in demand for electric power.

It is hardly a sure thing that new nuclear power plants will ever be built on Swedish soil. Demand is on the decline, and the Swedes are getting a good look at everything that can go wrong thanks to their neighbors, the Finns. The new Finnish reactor at Olkiluoto, western Europe’s first new construction project since the Chernobyl catastrophe in 1986, is providing arguments for foes of nuclear power: a doubling of the original cost estimates, constant construction delays, and constant bickering between the government and the French consortium doing the work.

Mineral Wealth in Afghanistan: The Saudi Arabia of Lithium?

The Grey Lady seemed positively ecstatic about recent discoveries of mineral wealth in Afghanistan in an article that appeared yesterday. The finds include iron, copper, gold, and a host of other valuable materials valued at a cool $1 trillion. The most significant of them all may turn out to be lithium. Initial analysis indicates deposits at only one location as large as those of Bolivia, the country that now has the world’s largest known reserves.

Lithium has become increasingly important lately as a component of small but powerful batteries. It will become a lot more important if fusion energy ever becomes a reality. I don’t expect this to happen anytime soon. Even if the remaining scientific hurdles can be overcome, the engineering difficulties of maintaining the extreme conditions necessary for fusion reliably over the long periods necessary to extract useful electric power would be daunting. Fusion power would likely be too expensive to compete with alternative energy sources under the best of circumstances. However, that’s my opinion, and a good number of very intelligent scientists disagree with me. If they’re right, and the upcoming proof of principle experiments at the National Ignition Facility prove far more successful than I expect, or some scientific breakthrough enables us to tame fusion on much smaller and less costly machines, fusion power may yet become a reality.

In that case, lithium may play a far more substantial role in energy production than it ever could as a component of batteries. It could literally become the metallic “oil” of the future. The reason for that is the fact that the easiest fusion reaction to tame is that between two heavy isotopes of hydrogen; namely, deuterium and tritium.  The “cross section” for the fusion reaction between these two isotopes, meaning the probability that it will occur under given conditions, becomes significant at substantially lower temperatures and pressures than competing candidates.  The fly in the ointment is the availability of fuel material.  Deuterium is abundant in nature.  Tritium, however, is not.  It must be produced artificially.  The raw material is lithium.

It happens that the fusion reaction between deuterium and tritium results in the production of a helium nucleus and a very energetic neutron.  This neutron can cause reactions in either of the two most common naturally occurring isotopes of lithium, Li-6 and Li-7, that produce tritium.  Thus, the fusion reactions that may one day produce energy for electric power could also be leveraged to breed tritium if the reaction were made to take place in the vicinity of lithium, either in a surrounding blanket or one of several other more fanciful proposed arrangements.   

As noted above, I don’t think that day is coming anytime soon.  If it when it does, Afghanistan may well become the Saudi Arabia of a new technological era of energy production.

Depleted Uranium: The Hysteria Rolls On

As I’ve pointed out in previous posts, it doesn’t make a lot of sense to use depleted uranium (DU) as ammunition because of its potential value as an energy source. Other than that, its substantial advantages as a penetrator for defeating armored targets are likely grossly outweighed by the value of the propaganda weapon we hand to our enemies when we use it, not to mention the massive cost of litigating cases brought by lawyers who are well aware of the potential value of DU hysteria for lining their pockets. That hysteria lost touch with reality long ago, and continues to grow. A glance at the facts should be enough to cure anyone of an overweening faith in the intelligence of human beings.

The basic propaganda line relating to DU weapons is that a) Great increases in cancer and other health problems are experienced in areas where they are used, and b) Most of these health problems are due to radioactivity from DU.  The professionally pious have devoted a great deal of webspace to the subject, typically short on facts but with lots of pictures of terribly deformed infants and, as usual, featuring themselves as noble saviors of humanity. Those with strong stomachs can find examples here, here and here. It’s all completely bogus, but the truth has never been more than a minor inconvenience for ideological poseurs.

The World Health Organization, public health arm of the UN, an organization that has not been notably chummy with the US of late, debunked the DU hysteria in a report that appeared in 2001 (click on the link to see the document). Quoting from the report,

For the general population it is unlikely that the exposure to depleted uranium will significantly exceed the normal background uranium levels.

Measurements of depleted uranium at sites where depleted uranium munitions were used indicate only localized (within a few tens of metres of the impact site) contamination at the ground surface.

General screening or monitoring for possible depleted uranium-related health effects in populations living in conflict areas where depleted uranium has been used is not necessary. Individuals who believe they have been exposed to excessive amounts of depleted uranium should consult their medical practitioner for examination, appropriate treatment of any symptoms and follow-up.

The potential external dose received in the vicinity of a target following attack by DU munitions has been theoretically estimated to be in the order of 4 μSv/year (UNEP/UNCHS, 1999) based on gamma ray exposure. Such doses are small when compared to recommended guidelines for human exposure to ionizing radiation (20 mSv/annum for a worker for penetrating whole body radiation or 500 mSv/year for skin (BSS, 1996).

Of course, the poseurs dismiss such stuff with a wave of the hand, claiming that, for reasons known only to them, the authors of the report suppressed damning evidence, or didn’t consider certain miraculous processes whereby the DU can be transported into the bodies of its victims without showing up in urine samples.  If one points out, for example, that natural background radiation in places such as Iran and India is much higher than any increase due to DU in the places where all the birth defects and illness is supposedly taking place, without ill effects to the local populations, they merely reply that the DU is carried on insoluble particles, that are infinitely more dangerous than natural uranium.  If it is pointed out that, in that case, it would actually be much more difficult for DU to cause birth defects because the rate at which the body carries insoluble compounds to the vicinity of the reproductive organs is an order of magnitude less than for soluble uranium compounds, or that it is much more difficult for insoluble compounds to get into the food chain, they quickly change tack.  Suddenly, the DU becomes soluble, and the circle is squared. 

A moment’s rational consideration of the facts demolishes the DU hype.  For example, it is claimed that 320 tons of DU were used in the Gulf War in 1991 and 1700 tons in the invasion of Iraq in 2003.  Those numbers pale in comparison to the approximately 9000 Tons of natural uranium and 22400 tons of thorium currently released each year from the burning of coal.  Much of this material is pumped directly into the atmosphere in the form of particulates that easily enter the lungs.  It is far more likely to contaminate nearby population centers in this form than the byproducts of DU munitions.  Coal consumption in China alone is over 2 million metric tons per year, resulting in the yearly release of about 3000 tons of uranium and 7450 tons of thorium.  There have certainly been health problems downwind of these plants, but they’ve been due to plain old-fashioned air pollution.  There have been no massive increases in birth defects or radiation-related cancer, flying in the face of claims about DU’s supposedly demonic power to sicken and kill.  Uranium absorbed in the body will show up in the urine, whether it is ingested in soluble or insoluble form.  Yet, despite massive screening of military veterans, ongoing studies find no persistent elevation of U concentrations beyond that found in the general population other than in soldiers actually hit by DU fragments or involved in friendly fire accidents.

Studies of uranium miners confirm the absurdity of the inflated DU claims.  Exposure to increased levels of uranium dust has not been associated with increases incidence of cancer, even in older miners.  Increased levels of lung cancer in such workers certainly have been detected, but it is associated with the breathing of high concentrations of radon in confined spaces.  The contribution of DU to radon gas concentrations in the atmosphere in Iraq is utterly insignificant compared to natural seepage from the earth and release by coal plant pollution.  Meanwhile, massive use of chemical weapons in the Iran-Iraq war, the sabotage and burning of hundreds of oil wells after the first Gulf War, and the release of a host of carcinogenic chemicals in the process of oil production are somehow never considered as possible contributors to illness and birth defects, unless, of course, they happen to fit another narrative.

In a word, the DU propaganda is nonsense, but that doesn’t keep it from being effective.  Other than that, because of DU’s potential value as a fuel in future breeder reactors that will be available to us without the environmental and health hazards of mining new uranium, we are almost literally shooting silver bullets.  Under the circumstances, one wonders what possible justification there can be for the claim that the advantages of continued use of DU munitions outweigh the drawbacks.  Why are we working so hard to confirm the familiar claim that “military intelligence” is an oxymoron?

Japan Restarts the Monju Fast Breeder Reactor

It’s encouraging to learn that Japan has decided to restart its Monju fast breeder reactor. Among other things it will supply electricity to many Japanese households without releasing greenhouse gases in the process. If global warming is really a terrible threat to all mankind, one would think we would be building such energy sources as quickly as possible. One would, however, be wrong.

For global warming alarmists, the pose is everything and the reality nothing. You can tell because they have no interest in solutions to the problem that happen to be unfashionable. Fast breeder reactors are an excellent example. They produce electricity without releasing greenhouse gases, and without releasing the particulates that kill tens of thousands of people every year, while representing a smaller radioactive hazard than coal fired plants. In that respect the pathologically pious saviors of the environment are more or less as irrational as our military. After all, the Lone Ranger only shot silver bullets. They shoot depleted uranium bullets that are worth their weight in gold as potential sources of energy. Allow me to explain.

Imagine dropping an iron ball into a deep well. What happens when it hits the bottom? It releases energy, right?  If the bottom of the well were a sheet of glass, that energy would probably cause it to shatter.  The ball releases the energy because it has been accelerated by a force. In this case, it is the force of gravity. However, there are other forces in nature. One of them is the strong nuclear force. It is vastly more powerful than gravity, but is only effective at distances on the order of the size of an atomic nucleus. At that distance, however, when an “iron ball” in the form of a neutron happens along, it can make the nucleus of a heavy element such as uranium look like a very deep well indeed. Just like a real iron ball, when the neutron falls into the well, it releases energy. If you think of the nucleus as a drop of water, that energy can cause the drop to start jiggling and stretching, just like a real drop. If the neutron releases enough energy, it can even cause the “drop of water” to break into two, smaller drops, releasing more neutrons in the process. That’s what happens in nuclear fission. The neutrons released in the process can drop into other “wells,” resulting in more fission, leading to a self-sustaining chain reaction, which can be used in controlled form to power a reactor, or in uncontrolled form to cause an atomic explosion.

When a neutron falls into a nuclear well, the energy released is only large enough to actually split certain very heavy atoms.  One of them is uranium 235, or U235 for short, which occurs in nature as 0.7% of natural uranium.  The rest is mainly uranium 238, which generally doesn’t split unless the neutron is going very fast to begin with, and therefore has some of its own energy to contribute when it falls into the well.  Another of the “fissile” heavy atoms that can split even when a slow neutron falls into its well is plutonium 239.  It can also be used to power nuclear reactors.  It doesn’t occur in any significant amounts in nature.  However, it is produced in nuclear reactors.  Interestingly enough, the “raw material” for its production is the  U238 which makes up the lion’s share of natural uranium.  When a neutron falls into a U238 “well,” the nucleus usually doesn’t split, but can capture the neutron, becoming U239.  This nucleus then releases an electron, resulting in its transmutation into neptunium 239. The neptunium nucleus, in turn, releases another electron, leaving Pu239. 

Now, if we’ve produced Pu239, and Pu239 is the fuel for nuclear reactors, we should simply be able to keep the reactor running, gradually converting the U238 to Pu239 and “burning” it right along with the naturally occurring U235, right?  Wrong!  In order to change to Pu239, U238 has to capture a neutron, but neutrons are what’s necessary to keep the nuclear chain reaction going.  Take away too many neutrons and the chain reaction stops, shutting down the reactor.  That’s where “fast breeders” come in.

Recall that, if the neutron that falls into the well is going very fast, then it can add a substantial amount of its own energy to that which is released when it falls to the bottom of the nuclear well.  In some cases that can cause even U238 to split, or fission.  More importantly, however, when such a fast neutron causes an atom of “fissile” material, such as U235 or Pu239, to split, the number of neutrons released in the process goes up.  If enough extra neutrons are released, the chain reaction can keep going even if many of them are captured by U238 to produce Pu239.  This is what makes it possible for a fast breeder reactor to produce more fuel than it consumes.  In the process, it gives us access to the massive amounts of energy locked away in the U238.  Instead of wastefully burning up the U235 in natural uranium and throwing away the rest by, say, shooting it out of gatling guns, we can now burn a large proportion of the U238 as well. 

Under the circumstances, does it make much sense for the military to be turning this potentially invaluable material into projectiles?  Apart from being a grotesque waste of a potentially valuable resource, it also releases radiation into the environment.  Granted, the amount of radiation will be very low.  It takes over four billion years for half of the atoms in a chunk of U238 to decay, and since there are many other natural sources of radiation in the environment, it is generally difficult to detect its presence above the background noise.  That fact, however, has hardly prevented legions of freeloaders and their professionally virtuous advocates from pretending that any number of ills from hangnails to heart disease are all directly caused by that radiation, and getting gullible politicians to believe it.  Apart from the waste, is it worth the grief?  I think not.

If fast breeder reactors can vastly increase the amount of energy available from the limited quantities of uranium available to us, what is the point of building more conventional reactors that waste most of the available fuel?  If global warming is really such a terrible threat to mankind, and the environmental alarmists are really more concerned about actually doing something to address the threat than in striking heroic poses from the moral high ground and pretending to do something about it, why aren’t they on board as well?  Whatever the severity of the threat of global warming, fast breeder reactors, along with solar, wind, hydroelectric, and other sources of energy that do not emit greenhouse gases could substantially end that threat.  Why, then, aren’t we building them?

Japan's Monju Fast Breeder

Global Warming: FOXNews Posts a Statistically Significant Inaccuracy

“Global Warming in Last 15 Years Insignificant, U.K.’s Top Climate Scientist Admits.” That was the rather shocking headline of an article that appeared on the FOXNews site yesterday. The “top climate scientist” in question was Phil Jones, former head of the Climatic Research Unit (CRU) of the University of East Anglia. The banner beneath the headline elaborates:

The embattled ex-head of the research center at the heart of the Climate-gate scandal dropped a bombshell over the weekend, admitting in an interview with the BBC that there has been no global warming over the past 15 years.

One can only assume the journalist who composed the headline acted out of ignorance rather than malice, as the mistake is “corrected” a few paragraphs into the article:

In response to the question, “do you agree that from 1995 to the present there has been no statistically significant global warming?”, Jones said yes, adding that the average increase of 0.12C per year over that time period “is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods.”

Apparently the layers of editors at Fox have a less than exemplary understanding of statistics.  They should, perhaps, learn something about them if they intend to continue writing articles about global warming.