Do We Really Need New Nukes?

If an article that just appeared in the LA Times is any indication, the agitation for jump-starting the nuclear weapons program at the Department of Energy (DOE) and the three nuclear weapons laboratories (Lawrence Livermore, Los Alamos, and Sandia National Laboratories) continues unabated. Entitled “New nuclear weapons needed, many experts say, pointing to aged arsenal,” it cites all the usual talking points of the weaponeers. For example,

Warheads in the nation’s stockpile are an average of 27 years old, which raises serious concerns about their reliability, they say. Provocative nuclear threats by Russian President Vladimir Putin have added to the pressure to not only design new weapons but conduct underground tests for the first time since 1992.

“It seems like common sense to me if you’re trying to keep an aging machine alive that’s well past its design life, then you’re treading on thin ice,” said Rep. Mac Thornberry (R-Texas), chairman-elect of the House Armed Services Committee. “Not to mention, we’re spending more and more to keep these things going.”

Thornbury also offered support for renewed testing, saying, “You don’t know how a car performs unless you turn the key over. Why would we accept anything less from a weapon that provides the foundation for which all our national security is based on?”

Such comments are entirely typical. They would make a lot of sense if the U.S. nuclear weapons program existed in a vacuum. However, it doesn’t. It exists in a world with several other major nuclear powers, and they all have the same problems. Under the circumstances, the fact that such problems exist and are shared by all the nuclear powers is less significant than the question of which nuclear power is best equipped to deal with them. The question of who will benefit by the building of new weapons and a resumption of nuclear testing depends on the answer to that question. If one country has a significant advantage over its rivals in dealing with a common problem as long as the status quo is maintained, then it would be very ill-advised to initiate a change to the status quo that would allow them to catch up.  At the moment, the United States is the country with an advantage. As noted in the article,

The U.S. has by far the greatest archive of test data, having conducted 1,032 nuclear tests. Russia conducted 715 and China only 45.

Beyond that, we have the ability to conduct tests with conventional explosives that mimic what goes on in the initial stages of a nuclear explosion, and superb diagnostics to extract a maximum of data from those tests. Perhaps more importantly, we have an unrivaled above ground experimental, or AGEX, capability. I refer to machines like Z at Sandia National Laboratories, or the NIF at Livermore, which are far more capable and powerful than similar facilities anywhere else in the world. Those who say they can’t access physical conditions relevant to those that occur in exploding nuclear weapons, or that they are useless for weapon effects or weapon physics experiments, either don’t know what they’re talking about or are attempting to deceive.

As far as the NIF is concerned, it is quite true that it has so far failed to achieve its fusion ignition milestone, but that by no means rules out the possibility that it ever will. More importantly, the NIF will remain a highly useful AGEX facility whether it achieves ignition or not. Indeed, before it was built, many of the weapons designers showed little interest in ignition. It would merely “muddy the waters,” making it more difficult for the diagnostics to precisely record the results of an experiment. The NIF could access weapons-relevant conditions without it. In fact, in spite of its failure to achieve ignition to date, the NIF has been a spectacular success as far as achieving its specifications are concerned. It is more than an order of magnitude more powerful than any previously existing laser system, its 192 laser beams are highly accurate, and its diagnostic suite is superb.

Another problem with the resumption of testing is that it will lead to the development of weapons that are much more likely to be used. Once the nuclear genie is out of the bottle, it will likely prove very difficult to put it back in. For example, again quoting the article,

John S. Foster Jr., former director of Lawrence Livermore National Laboratory and chief of Pentagon research during the Cold War, said the labs should design, develop and build prototype weapons that may be needed by the military in the future, including a very low-yield nuclear weapon that could be used with precision delivery systems, an electromagnetic pulse weapon that could destroy an enemy’s communications systems and a penetrating weapon to destroy deeply buried targets.

The commonly heard narrative at DOE goes something like this: “We need to develop small, precise, penetrating nuclear weapons because they will be a much better deterrent than the existing ones. Potential enemies are unlikely to believe that we would ever use one of the high yield weapons that are all that remain in the current arsenal. They would be far more likely to believe that we might use a small bunker buster that would minimize the possibility of significant collateral damage.” The problem with that narrative is that it’s true. We would be far more likely to use such a weapon than the ones in the current arsenal, and there would be no lack of voices within DOE and DoD calling for its use if an appropriate opportunity ever arose.

I can understand the agitation for a resumption of testing. It’s a lot sexier to make things that go boom than to serve as custodians for an aging pile of existing nukes. Unfortunately, the latter course is the wiser one. By resuming nuclear testing we would really be unilaterally surrendering a huge advantage, playing into the hands of our enemies and destabilizing the nuclear landscape at the same time.

But Wait! There are More “Worries” from The Edge!

I won’t parse all 150+ of them, but here are a few more that caught my eye.

Science writer and historian Michael Shermer, apparently channeling Sam Harris, is worried about the “Is-Ought Fallacy of Science and Morality.”  According to Shermer,

…most scientists have conceded the high ground of determining human values, morals, and ethics to philosophers, agreeing that science can only describe the way things are but never tell us how they ought to be. This is a mistake.

It’s only a mistake to the extent that there’s actually some “high ground” to be conceded.  There is not.  Assuming that Shermer is not referring to the trivial case of discovering mere opinions in the minds of individual humans, neither science nor philosophy is capable determining anything about objects that don’t exist.  Values, morals and ethics do not exist as objects.  They are not things-in-themselves.  They cannot leap out of the skulls of individuals and acquire a reality and legitimacy that transcends individual whim.  Certainly, large groups of individuals who discover that they have whims in common can band together and “scientifically” force their whims down the throats of less powerful groups and individuals, but, as they say, that don’t make it right.

Suppose we experience a holocaust of some kind, and only one human survived the mayhem.  No doubt he would still be able to imagine what it was like when there were large groups of other’s like himself.  He might recall how they behaved, “scientifically” categorizing their actions as “good” or “evil,” according to his own particular moral intuitions.  Supposed, now, that his life also flickered out.  What would be left of his whims?  Would the inanimate universe, spinning on towards its own destiny, care about them one way or the other.  Science can determine the properties and qualities of things.  Where, then, would the “good” and “evil” objects reside?  Would they still float about in the ether as disembodied spirits?  I’m afraid not.  Science can have nothing to say about objects that don’t exist.  Michael Shermer might feel “in his bones” that some version of “human flourishing” is “scientifically good,” but there is no reason at all why I or anyone else should agree with his opinion.  By all means, let us flourish together, if we all share that whim, but surely we can pursue that goal without tacking moral intuitions on to it.  “Scientific” morality is not only naive, but, as was just demonstrated by the Communists and the Nazis, extremely dangerous as well. According to Shermer,

We should be worried that scientists have given up the search for determining right and wrong…

In fact, if scientists cease looking for and seeking to study objects that plainly don’t exist, it would seem to me more reason for congratulations all around than worry.  Here’s a sample of the sort of “reasoning” Shermer uses to bolster his case:

We begin with the individual organism as the primary unit of biology and society because the organism is the principal target of natural selection and social evolution. Thus, the survival and flourishing of the individual organism—people in this context—is the basis of establishing values and morals, and so determining the conditions by which humans best flourish ought to be the goal of a science of morality. The constitutions of human societies ought to be built on the constitution of human nature, and science is the best tool we have for understanding our nature.

Forgive me for being blunt, but this is gibberish.  Natural selection can have no target, because it is an inanimate process, and can no more have a purpose or will than a stone.  “Thus, the survival and flourishing of the individual organism – people in this context – is the basis of establishing values and morals”??  Such “reasoning” reminds me of the old “Far Side” cartoon, in which one scientist turns to another and allows that he doesn’t quite understand the intermediate step in his proof:  “Miracle happens.”  If a volcano spits a molten mass into the air which falls to earth and becomes a rock, is not it, in the same sense, the “target” of the geologic processes that caused indigestion in the volcano?  Is not the survival and flourishing of that rock equally a universal “good?”

Of the remaining “worries,” this was the one that most worried me, but there were others.  Kevin Kelly, Editor at Large of Wired Magazine, was worried about the “Underpopulation Bomb.”  Noting the “Ur-worry” of overpopulation, Kelly writes,

While the global population of humans will continue to rise for at least another 40 years, demographic trends in full force today make it clear that a much bigger existential threat lies in global underpopulation.

Apparently the basis of Kelly’s worry is the assumption that, once the earths population peaks in 2050 or thereabouts, the decrease will inevitably continue until we hit zero and die out.  In his words, “That worry seems preposterous at first.”  I think it seem preposterous first and last.

Science writer Ed Regis is worried about, “Being Told That Our Destiny Is Among The Stars.”  After reciting the usual litany of technological reasons that human travel to the stars isn’t likely, he writes,

Apart from all of these difficulties, the more important point is that there is no good reason to make the trip in the first place. If we need a new “Earth 2.0,” then the Moon, Mars, Europa, or other intra-solar-system bodies are far more likely candidates for human colonization than are planets light years away.  So, however romantic and dreamy it might sound, and however much it might appeal to one’s youthful hankerings of “going into space,” interstellar flight remains a science-fictional concept—and with any luck it always will be.

In other words, he doesn’t want to go.  By all means, then, he should stay here.  I and many others, however, have a different whim.  We embrace the challenge of travel to the stars, and, when it comes to human survival, we feel existential Angst at the prospect of putting all of our eggs in one basket.  Whether “interstellar flight remains a science-fiction concept” at the moment depends on how broadly you define “we.”  I see no reason why “we” should be limited to one species.  After all, any species you could mention is related to all the rest.  Interstellar travel may not be a technologically feasible option for me at the moment, but it is certainly feasible for my relatives on the planet, and at a cost that is relatively trivial.  Many simpler life forms can potentially survive tens of thousands of years in interstellar space.  I am of the opinion that we should send them on their way, and the sooner the better.

I do share some of the other worries of the Edge contributors.  I agree, for example, with historian Noga Arikha’s worry about, “Presentism – the prospect of collective amnesia,” or, as she puts it, the “historical blankness” promoted by the Internet.  In all fairness, the Internet has provided unprecedented access to historical source material.  However, to find it you need to have the historical background to know what you’re looking for.  That background about the past can be hard to develop in the glare of all the fascinating information available about the here and now.  I also agree with physicist Anton Zeilinger’s worry about, “Losing Completeness – that we are increasingly losing the formal and informal bridges between different intellectual, mental, and humanistic approaches to seeing the world.”  It’s an enduring problem.  The name “university” was already a misnomer 200 years ago, and in the meantime the problem has only become worse.  Those who can see the “big picture” and have the talent to describe it to others are in greater demand than ever before.  Finally, I agree with astrophysicist Martin Rees’ worry that, “We Are In Denial About Catastrophic Risks.”  In particular, I agree with his comment to the effect that,

The ‘anthropocene’ era, when the main global threats come from humans and not from nature, began with the mass deployment of thermonuclear weapons. Throughout the Cold War, there were several occasions when the superpowers could have stumbled toward nuclear Armageddon through muddle or miscalculation. Those who lived anxiously through the Cuba crisis would have been not merely anxious but paralytically scared had they realized just how close the world then was to catastrophe.

This threat is still with us.  It is not “in abeyance” because of the end of the cold war, nor does that fact that nuclear weapons have not been used since World War II mean that they will never be used again.  They will.  It is not a question of “if,” but “when.”

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.

UPDATE:  Steven Den Beste gets it right at Hot Air.  His commenters throw out the usual red herrings about the US choosing U235 and Pu239 over U233 in the Manhattan Project (for good reasons that had nothing to do with U233’s suitability as a bomb material) and the grossly exaggerated and misunderstood problem with U232.  You don’t have to be a nuclear engineer to see through these fallacious arguments.  The relevant information is all out there on the web, it’s not classified, and it can be understood by any bright high school student who takes the time to get the facts.

Hiroshima and the Revisionists

Another August 6, another round of historial revisionism. The fabricators of adjusted realities always make their appearance about this time every year to spin their yarns about how the atomic bombing of Japan wasn’t really necessary, how Japan was just on the point of surrendering but the bombs were dropped anyway for an assortment of nefarious and evil reasons by the nefarious and evil rulers of a nefarious and evil country, how the “real” reason for the surrender was the obvious and long expected Russian entry into the war, how this or that scrap of information or this or that “official” report “proves” that the bombings didn’t in any way hasten or even encourage surrender, etc., etc. These periodic attempts to reinvent the past come from any number of different sources. Of course, the pathologically pious head the list; those whose penchant for imagining themselves to be the “saviors of mankind” goes beyond mere daydreaming to the invention of alternate worlds, drawn in colors of stark black and white, in which they appear in the role of virtuous heros, eternally saving the rest of us from evil. Of course, they never quite accomplish that worthy goal, and the “victims” they strive so mightily to save somehow always seem to remain “victims” in spite of their most heroic efforts, because victims are indispensible. After all, if the victims were ever really saved, virtuous heros would become superfluous.

But I digress. Of course, there is also Japanese officialdom. Ever since the end of the war, they have been busy rationalizing, relativizing, and generally seeking to consign to oblivion such horrific crimes as the rape of Nanking, the deliberate slaughter of the civilian population of Manila (in both of which cities more civilians died than in Hiroshima), the Bataan Death March, the deliberate starving and murder of prisoners, the wholesale rape of a generation of Korean women,



germ warfare experiments with human guinea pigs, etc., etc. The bomb has always been their most effective foil for diverting attention from their country’s criminal past. Other than that, there are the legions of Ameria-haters worldwide for whom the United States is well-suited for the role of “out-group,” satisfying the universal need wired in the human brain for an evil enemy.

It is usually easy to identify historical revisionists.  They tip their hands by insisting on a version of reality that allows no room for doubt, and that neatly fits their ideological preconceptions.  In this case, for example, in spite of the undeniable coincidence of the atomic bombing and the surrender of Japan, they insist that there was absolutely no connection, and that the bombing had nothing at all to do with the Japanese decision to capitulate.  Obviously, especially in view of the careful destruction of relevant documents by Japanese officials, it is irrational to claim that it has absolutely been proved that the bombing and the surrender were purely coincidental, and the former’s contribution to the latter was trivial at best.  That, however, is precisely what the revisionists claim.  Look at their books and essays, and you will also find that they invariably leave out salient facts that don’t fit the altered reality they are trying to construct, and that other facts are “reinterpreted” to give them a significance they don’t deserve. 

Readers who have been around long enough may recall a previous round of Hiroshima revisionism on the occasion of the 50th anniversary of the bombing back in 1995.  Earlier in the year, officials at the Smithsonian Institution, a magnet for leftist academics whose tastes run to interpreting all American history as the story of an oppressor’s playground on which a series of invariably  pure, noble and morally immaculate classes of victims were brutalized by an invariably greedy, selfish, and evil ruling class, had attempted to introduce the now familiar adjustments to reality in conjuction with the Institution’s planned display of the Enola Gay.  Fortunately, enough people with firsthand knowledge of what really happened and who objected to the bowdlerization of history, were around at the time to mount an effective resistance to the fabricators.  Now most of the eyewitnesses have passed from the scene.  It is, therefore, all the more important that the critical source material relating to the atomic bombing be preserved and made easily accessible. 

Revisionists of one stripe or another will always be with us.  At different times and in different places, they have succeeded in constructing alternate realities in spite of the existence of a far greater volume and variety of source material than exists in the case of the atomic bombing of Japan.  Schools in much of the US South, for example, raised generations of students who firmly believed that the Civil War “really” occurred for any number of reasons besides slavery, in spite of overwhelming evidence documenting that the leaders of the South believed it was about slavery, the leaders of the North believed it was about slavery, the populations in both sections believed it was about slavery, and foreign observers were unanimous in confirming that it was about slavery.  Today Holocaust deniers control the public narrative in much of the Middle East.  In both of those cases, the source material available to document what really happened was orders of magnitude larger than what remains pertinent to the atomic bombing of Japan.  The Hiroshima revisionists would seem to have a much easier task.  The amount of documentation it will be necessary for them to drop down the “memory hole” is a great deal smaller, and their attempts to construct a mythical reality may consequently turn out to be a great deal more successful than those of the Iranian theocracy, or the “Southern heritage” crowd.

History can and will be falsified.  In the case of Hiroshima, those who are attempting to revise it are influential and determined.  The antidote to revisionism is the preservation of facts.  The truth is important.  One must hope that enough facts about the atomic bombing of Japan will be preserved to give future generations at least a fighting chance of finding it.

UPDATE: This article by Richard B. Frank (hattip ChicagoBoyz), entitled “Why Truman Dropped the Bomb, which appeared in the Weekly Standard in 2005, is a must read for those seeking the facts about the atomic bombing of Japan.  Money quote: 

There are a good many more points that now extend our understanding beyond the debates of 1995. But it is clear that all three of the critics’ central premises are wrong. The Japanese did not see their situation as catastrophically hopeless. They were not seeking to surrender, but pursuing a negotiated end to the war that preserved the old order in Japan, not just a figurehead emperor. Finally, thanks to radio intelligence, American leaders, far from knowing that peace was at hand, understood–as one analytical piece in the “Magic” Far East Summary stated in July 1945, after a review of both the military and diplomatic intercepts–that “until the Japanese leaders realize that an invasion can not be repelled, there is little likelihood that they will accept any peace terms satisfactory to the Allies.” This cannot be improved upon as a succinct and accurate summary of the military and diplomatic realities of the summer of 1945.