“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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