Inertial confinement fusion – Page 3

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.

Crunch Time for the National Ignition Facility

ICF The news from California is encouraging. In an article recently published in Science and summarized on the website of Lawrence Livermore National Laboratory (LLNL), scientists working at the National Ignition Facility (NIF) report efficient coupling of energy from all 192 beams of the giant facility into a hohlraum target similar to the one that will be used later this year in the first attempts to achieve fusion ignition and “breakeven,” usually defined as more energy production from fusion than was carried in the laser beams used to hit the target. The design energy of the NIF is 1.8 megajoules, and, according to the latest reports from Livermore, the threshold of one megajoule has already been achieved.

In inertial confinement fusion, or ICF, the target, a thin, spherical shell containing a mixture of deuterium and tritium, two heavy isotopes of hydrogen, is first compressed and imploded to very high densities. A series of converging shocks then create a “hot spot” in the center of the compressed material, setting off fusion reactions which release enough energy to set off a “burn wave.” This wave propagates out through the remaining fuel material, heating it to fusion energies as well. The process is known as inertial confinement fusion because it takes place so fast (on the order of a nanosecond) that the material’s own inertia holds it in place long enough for the fusion reactions to occur. There are two basic approaches; direct drive, in which the laser beams hit the fusion target directly, and indirect drive, the process that will be used in the upcoming Livermore ignition experiments, in which the beams are shot into a hollow can or “hohlraum,” producing x-rays when they hit the inner walls. These x-rays then implode and ignite the target.

A potential problem that must be overcome in ICF is known as laser plasma interactions (LPI). These are parasitic interactions which can soak up laser energy and quench the fusion process. According to the Livermore paper, special grids at the hohlraum entrance holes were used in the latest experiments, allowing the use of LPI to “tweak” the incoming beams, steering them to just the right spots. This recent (and elegant) innovation allows the exploitation of a process that has always been considered a major headache in the past to actually improve the chances of achieving igntion.

The BBC and Spiegel both have articles about the latest experiments today, conflating the energy and military applications of the NIF as usual. According to the Spiegel article, for example, it will be necessary for the lasers in a fusion reactor to hit the target ten times a second, whereas hours are necessary between shots at the NIF. The reason, of course, is that the NIF was never designed as an energy project, but is being funded by the National Nuclear Security Administration (NNSA) to conduct nuclear weapons experiments. If ignition is achieved, the prospects for fusion energy will certainly be improved, but the prospects aren’t nearly as bright as the press releases from LLNL would imply. It will still be necessary to overcome a great number of scientific and engineering hurdles before the process can ever become useful and economical as a source of energy.

I am not optimistic about the success of the upcoming experiments. I suspect it will be too difficult to achieve the fine beam energy balance and symmetry that will be necessary to ignite the central “hot spot.” It will take more than one converging shock to do the job. Several will be necessary, moving inward through the target material at just the right speed to converge at a small spot at the center. If they really pull it off, I will be surprised, but will be more than happy to eat crow. A lot of very talented scientists have dedicated their careers to the quest for fusion, and I’m keeping my fingers crossed for them.

Even if these ignition experiments fail, it won’t mean the end for fusion by a long shot. We know we can achieve the high fuel densities needed for inertial fusion, and there are other ways of creating the “hot spot” needed to achieve ignition, such as “fast ignitor.” Other approaches to fusion keep showing up in the scientific literature, and I can’t help but think that, eventually, one of them will succeed.

Alternative Energy Myths and the Nuclear Orphan

Another interesting article turned up in Foreign Policy recently entitled “Seven Myths about Alternative Energy,” by legacy media environmental journalist Michael Grunwald. His collection of “myths” provides a revealing look at the psychology of the “green” would be saviors of the planet. Let’s run down his list.

Myth number one is, “We need to do everything possible to promote alternative energy.” Grunwald prefers a different emphasis: “…though the world should do everything sensible to promote alternative energy, there’s no point trying to do everything possible.” The information content of this bit of wordsmithing as it stands is epsilon (a very small number). From the left to the right of the ideological spectrum, I have never encountered anyone who proposes that we should do everything possible to promote alternative energy, including things that don’t make sense. Reading on, one notes that, in a blurb that is supposed to be about alternative energy, Grunwald studiously avoids any mention of such credible candidates as wind, solar, and geothermal. Rather, he directs his ire at alternatives that aren’t quite ready for prime time: “Hydrogen cars, cold fusion, and other speculative technologies might sound cool, but they could divert valuable resources from ideas that are already achievable and cost-effective.” This statement is logically absurd.

Consider fusion for example. The amount of resources being “diverted” worldwide to the energy applications of fusion, including both its hot and cold flavors, is utterly insignificant in comparison to the amount we spend on energy production, the total amount we spend on research, or any other number one could reasonably compare it to. I am no fusion true believer. It is a high risk technology, and one that will almost certainly not figure in the world’s energy equation before Grunwald’s target date of 2050. If, on the other hand, we can overcome the daunting technological hurdles Mother Nature has put in our path and find a way to use it, fusion has the potential to meet the world’s energy needs indefinitely while releasing no greenhouse gases and with an insignificant radiological hazard compared to nuclear and coal. There are many interesting research efforts afoot to finesse the technological problems that beset such “traditional” approaches as magnetic and inertial confinement fusion. The amount of research dollars being devoted to these efforts is miniscule. They can all be characterized as high risk, but it is hardly implausible to suggest that, eventually, one of them will succeed. If so, the payoff will be enormous. The problem of greenhouse gas emissions might be solved once and for all, without the severe environmental impact of covering massive areas with wind farms and solar collectors. In a word, if we are truly worried about global warming, it would be utterly reckless and senseless to eliminate the tiny resources we currently devote to energy applications of fusion. As we shall see, Grunwald’s reasons for rejecting such alternatives, not to mention the seeming lack of interest in such immediately available sources such as wind, solar and geothermal have more to do with psychology than logic.

Moving on to myths 2 and 3, Grunwald turns his ire on biofuels, such as ethanol derived from corn. No surprise there, as he has often hammered the “clean energy” hype emanating from that sector in the past. He notes that such “renewable fuels” have been heavily promoted by governments around the world, including ours, but points out, “…so far in the real world, the cures — mostly ethanol derived from corn in the United States or biodiesel derived from palm oil, soybeans, and rapeseed in Europe — have been significantly worse than the disease.” So far, so good. I have yet to see a convincing argument in favor of biofuels that seriously addresses such problems as the facts that their production results in a net loss in energy, horrific environmental damage, and a reduction in the world’s food supply. The problem with myths 2 and 3 is that they are strawmen. I know of no credible authority outside of industry advocates who is seriously suggesting that biofuels are a plausible solution to global warming.

Grunwald’s myth 4 is, “Nuclear power is the cure for our addiction to coal.” This seems counterintuitive, since, according to the most reliable studies, the carbon footprint of nuclear plants is a small fraction of that of its fossil fuel alternatives. Among the reasons Grunwald cites for dismissing the nuclear alternative is the fact that it will be too slow coming on line to make a dent in carbon emissions in the near term. That’s quite true, but while one may certainly point to it as an unfortunate fact of life, it is certainly no reason to abandon nuclear altogether. If global warming is really the problem Grunwald claims it is, than surely late is better than never.

Be that as it may, Grunwald cites cost as the real show stopper for nuclear power. As he puts it,

Nuke plants are supposed to be expensive to build but cheap to operate. Unfortunately, they’re turning out to be really, really expensive to build; their cost estimates have quadrupled in less than a decade. Energy guru Amory Lovins has calculated that new nukes will cost nearly three times as much as wind — and that was before their construction costs exploded for a variety of reasons, including the global credit crunch, the atrophying of the nuclear labor force, and a supplier squeeze symbolized by a Japanese company’s worldwide monopoly on steel-forging for reactors.

At this point, the familiar anti-nuclear “green” narrative emerges from the mist, and Grunwald leaves logical argument in the dust. Amory Lovins is certainly someone worth listening to. He is also one of the legacy media’s beloved “mavericks,” and hardly someone whose cost estimates represent the final word on the subject. In fact, if one looks at the credible cost estimates of nuclear versus its alternatives, not just from sources connected with the industry, but, for example, from a study done in 2003 by an interdisciplinary group of MIT professors and updated in 2009, the suggestion that nuclear is “really, really expensive” compared to the alternatives may be dismissed as bunk. Grunwald might have had some credibility if he had taken the trouble to dispute these estimates with arguments more substantial than anecdotes about Japanese steel monopolies. As it is, it is clear that his rejection of nuclear has nothing to do with its intrinsic merits or lack thereof. Rather, it simply doesn’t fit in the “conservation and efficiency” narrative he shares with Lovins. Grunwald uses myths 5 through 7 to outline the narrative.

It turns out that myth 5, “There is no silver bullet to the energy crisis,” is only a pseudo-myth. As Grunwald himself admits, “Probably not.” Be that as it may, he clearly has a silver bullet in mind; efficiency. In his words,

But some bullets are a lot better than others; we ought to give them our best shot before we commit to evidently inferior bullets. And one renewable energy resource is the cleanest, cheapest, and most abundant of them all. It doesn’t induce deforestation or require elaborate security. It doesn’t depend on the weather. And it won’t take years to build or bring to market; it’s already universally available. It is called “efficiency.”

Conservation and energy efficiency are certainly laudable goals, and ones that should be pursued aggressively. However, Grunwald’s problem is that he sees them in typical journalistic black and white. They are the one true path to salvation, as opposed to the “inferior bullets.” This setting up of artificial barriers separating the plausible alternatives to solving our energy problems into a “good” approach standing in opposition to other “bad” approaches is more a reflection of human psychology than logic. For example, the hard fact is that rejection of nuclear power has and will continue to result in the building of more fossil-fired generation capacity. That is precisely what is going on in Germany, whose “Greens” have forced the foolhardy decision to shut down nuclear plants rather than refurbish them and keep them on line, resulting in the building of new coal plants even as we speak, and in defiance of these same “Greens” warm, fuzzy rhetoric about the virtues of alternative energy. Similarly, Grunwald’s blasé attitude towards alternatives such as wind, solar, and geothermal is more likely to encourage complacency than, for example, an aggressive approach to building the power transmission infrastructure we need to accommodate these new technologies. According to Grunwald,

Al Gore has a reasonably plausible plan for zero-emissions power by 2020; he envisions an ambitious 28 percent decrease in demand through efficiency, plus some ambitious increases in supply from wind, solar, and geothermal energy. But we don’t even have to reduce our fossil fuel use to zero to reach our 2020 targets. We just have to use less.

Al Gore may be right, but he may also be wrong. Regardless, it would be foolish of us to put all of our eggs in one basket. In particular, it would be very foolish to cut off the already miniscule support we are currently giving to high risk, high payoff technologies such as fusion. It is highly unlikely that global energy demand will go down as the world’s population continues to increase, or that the citizens of emerging economic powers such as India and China will continue to be satisfied with a third world lifestyle. Ignoring technologies that could plausibly solve the problem of global warming because Grunwald thinks they are dumb would be both illogical and, potentially, suicidal. His attitude is typical of the representatives of what H. L. Mencken used to call the “uplift” on the left. Though I suspect most of them don’t realize it themselves, they are far more interested in posing as saviors of mankind than in actually saving mankind. Hence, for example, the hand waving dismissal of nuclear technology. The Grunwalds of the world will continue to dismiss it, not because it is not a plausible piece of an overall solution to the problem of global warming, but because it is unfashionable. If one would strike a truly heroic pose, one cannot afford to be unfashionable.

The Big NIF Dis

It appears the dedication ceremony for the National Ignition Facility (NIF) has come and gone, but a rather important guest who had promised to be there turned up missing. I refer to Secretary Chu, avatar of alternative energy (er, politically correct alternative energy that is). At the last moment he discovered that he was “too busy” to attend, (or did he get a headache, I forget?).

True, the NIF was built as a weapons facility, and that’s a big strike against it in the warm, fuzzy world of today. That’s not the whole story, though. The “ignition” in National Ignition Facility means inertial fusion ignition, and a great number of dedicated scientists have devoted their careers to the proposition that fusion ignition will usher in an era of clean energy with a virtually limitless fuel supply. I, personally, find that proposition dubious, at least with the hot spot ignition approach currently envisioned for the NIF. However, a lot of outstanding scientists who probably know more of the relevant physics than I are not similarly dubious, and believe the daunting technical, economic, and engineering hurdles on the path to inertial fusion energy can be overcome.

Now, 35 long, difficult years after the first confirmation of fusion neutrons produced by laser implosion, we finally have an operational facility capable, according to the theorists, of achieving significant energy gain, and we stand on the threshold of the decisive series of ignition experiments that are likely to determine whether they’re right or wrong once and for all. It seems to me that those who have dedicated their lives to a goal they believe will be of incalculable value to all mankind should now, at least, be given a fair shot at achieving that goal. The tool they need is in their hands. Given what’s at stake, not to mention the massive amounts we’ve recently been spending on far less worthy goals, does it not seem logical to give them a chance?

Perhaps Secretary Chu does not agree. It would certainly seem so. NNSA, a part of DOE, manages the NIF, and its budget has been cut to the bare bones. This budget slashing cannot help but affect the coming campaign of ignition experiments at the facility. Well, then, if Secretary Chu does not agree, perhaps it would better befit the leader that he is supposed to be to stand up and explain why, instead of playing hide and seek at dedication ceremonies. Those who have worked long and faithfully to make this project a reality deserve no less.

“Fusion Energy” and the National Ignition Facility (NIF)

Oh-oh! Here’s something that’s bound to give the fission guys over at Atomic Insights heartburn. The National Ignition Facility (NIF) is in the news again, and even made the lead story on the Foxnews website this morning! It seems the dark side at DOE is finally, belatedly, getting some respect from Secretary Chu, not to mention the Governator and a host of other worthies. Odd, isn’t it, that, in these days of rampant global warming, the Secretary of Energy should have taken so little interest in this potential source of unlimited, pollution free energy? What, say you? Well, yes, perhaps I do exaggerate.

In fact, the NIF is, and always has been, intended as an above ground facility for nuclear weapons experiments. As such, it is probably justified, as it will give us access to extreme physical conditions relevant to nuclear weapons that, at least until the French Megajoule laser (LMJ) comes on line, cannot be reproduced at any other facility. It is important that we have such facilities because, among other things, they constitute one more argument against the resumption of nuclear testing, a step that we would be very ill-advised to take.

Why, then, one might ask, do NIF Director Ed Moses’ comments to Fox about the new facility relate almost exclusively to potential energy applications? Well, among other things, because clean energy is a rather more fashionable cause than nuclear weapons technology these days. I’m loathe to criticize Ed, who, in spite of what some might term objectionable personal quirks, did a brilliant job of pulling the NIF Project back from the brink of disaster and completing it within the budget and time constraints he was given when he took it over. However, he may be overselling the energy angle.

Inertial confinement fusion (ICF) has always been a “dual use” technology, and there are many highly capable scientists throughout the world who still believe that it is the ultimate answer to our future energy needs. I am dubious, but still have a great deal of respect for the old knights, now growing increasingly long in the tooth, who continue riding towards that El Dorado. May they one day make me eat crow!

But all that is beside the point. The Federal Advisory Committees that recommended proceeding with the NIF, and the federal officials who secured funding for the project, never considered justifying it as other than a weapons project. From the beginning it was projected that about 15% of the available time on the facility would be devoted to non-weapons related experiments, not only devoted to energy applications, but to laboratory astrophysics, high energy density plasma physics, etc. Other than that, the NIF will be used entirely for weapon physics and weapon effect experiments. In other words, when Ed tells us that, “”It would change how we look at global warming. It would change pollution. It would change all of those things. This is a small investment for that great payback,” he is indulging in a bit of hyperbole.

In the first place, I will be surprised if the NIF ever achieves ignition, at least using the currently envisioned indirect drive approach. It will be necessary to compress the fuel material to extremely high density, keeping it as “cold” as possible in the process, and then ignite it by coaxing a series of spherical shock waves to heat up a small spot in the center by getting them all to converge on that spot at exactly the same time. Again, if they can do it, I will cheerfully eat crow. If they do, though, getting useful energy out will hardly be just around the corner. It will first be necessary to overcome a host of daunting engineering challenges, such as breeding enough tritium, one of the necessary fuel materials, to keep the reactor going.

Well, be that as it may, the NIF has been a long time coming – much longer than anyone expected in the beginning. Now that the facility is finally on line, the least we can do is wish the NIF staff at Livermore success in finally reaching the ignition goal that has eluded our grasp for so long.

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