Plutonium and the Return to Nuclear Power

I’m on board when it comes to restarting the nuclear industry – with reservations. What’s not to like? No carbon footprint. Less release of dangerous radionuclides into the atmosphere than coal plants. No need to pave thousands of square miles of environmentally fragile desert with solar collectors, windmills, and similar “environmentally friendly” and “sustainable” energy sources.

There is one big potential problem, though. When you burn uranium in a conventional nuclear reactor, you breed plutonium. The spent fuel rods currently stored on site at every nuclear plant in the country are laced with the stuff. You don’t need fancy centrifuges or gas diffusion plants to separate the plutonium. Any reasonably skilled chemist could do it. Once you’ve separated the plutonium, you have the one key ingredient you need to make a nuclear weapon. Oh, I know, it won’t be weapons grade plutonium, but no matter. The United States conducted a successful nuclear test with reactor grade plutonium.

Why, you ask, haven’t terrorists already stolen a batch of fuel rods if it’s so simple. Well, at the moment, the problem is that they’re so highly radioactive that bad actors would probably fry themselves before they could do any damage. They won’t stay that way, though. The radionuclides that make fuel rods so “hot” when it comes to emitting radiation have a certain half life. They decay, and become less radioactive at an exponential rate. At some point, they will become safe enough to handle, even without specialized equipment. The exact time will depend on the material configuration of the fuel rods when they were produced, and the degree of risk the person handling them is willing to take. True, we’re probably talking hundreds or thousands of years in the future, but beyond what date can we ignore the welfare of future generations? When does it become OK to subject them to the risk of nuclear annihilation?

Fortunately, there are solutions to the problem. One is fuel recycling, in which the plutonium from spent rods would be extracted and recycled into new fuel rods. An even better one is building breeder reactors to go along with the recycling. The problem with conventional reactors is that they use up the U235 in natural uranium as fuel. Unfortunately, only seven tenths of one percent of natural uranium is isotope 235, and the rest is 238. Depleted uranium is mostly U238, being what’s left over when the U235 is separated.

With breeder reactors, the U238 can be gradually converted into plutonium 239, a reactor fuel. In that way, a much greater percentage of the natural uranium could be converted to energy, greatly extending the time available to us for figuring out what to do when that fuel supply runs out. Alternatively, thorium, which can be converted into U233, another fissile material, could be used in the breeders. U233 has the very significant advantage of not being chemically separable from other uranium isotopes, and would, therefore be much more difficult to weaponize than plutonium.

Plutonium-based energy production is not benign. It would require tight security standards at every step along the fuel chain. But, then again, no known method of producing energy is benign, including the “environmentally friendly” ones noted above. If the choice were mine to make, I think I would agree with the guys over at Atomic Insights.

Meanwhile, it strikes me as a little crazy that we are gratuitously pumping potentially energy rich depleted uranium slugs out of the barrels of gatling guns. If we really start running out of energy, others might notice there are better uses for the stuff as well.

Nuclear Terrorism and Nuclear Smuggling: Will Portal Radiation Detectors Save Us?

Well, no. Not if you’re talking about interdicting a nuclear weapon or its components. The syllogism works like this: 1) Anyone with enough Special Nuclear Material (SNM) to assemble a bomb would have to be brain dead to try to tote it through a radiation portal. 2) Anyone clever enough to acquire enough SNM to make a bomb is not brain dead. 3) Therefore, anyone with enough SNM to make a bomb will not attempt to carry it through a radiation portal. (Apropos SNM, the image to the left shows a guy holding a plutonium “button.” He probably wouldn’t do that if it were radioactive enough to kill him outright.)

The location of radiation portals and their approximate performance parameters are easily accessible to potential nuclear smugglers at any of a host of “intelligence” websites online. The question then becomes, can they avoid passing them? Of course! How many of the millions of illegal immigrants currently in the country do you suppose passed through radiation portals? There are a virtually infinite number of ways to smuggle SNM into the country that don’t involve passing through radiation detectors, ranging from slingshots to personal submarines. The unclassified amounts of SNM deemed sufficient for a nuclear explosive device are 25 kilograms of highly enriched uranium, or 4 kilograms of weapons grade plutonium. However, there’s no need whatsoever to smuggle such large quantities all at once. Terrorists could “smuggle by components.” In other words, they could simply smuggle the SNM into the country bit by bit until they had enough for a weapon.

By the way, dear reader, if you are one of those whose tastes run to calculating how much SNM it would “really” take to make a bomb, here’s some advice for you: Don’t do it! In general, don’t try to impress everyone with how clever you are by speculating on the design details of nuclear weapons. You will take yourself right out of the dialogue, because anyone who really knows anything about such matters is liable to have a “Q” security clearance, and, according to DOE guidelines, will be unable to comment on whatever brilliant conclusions you’ve come to on the subject.

In fact, it is absolutely unnecessary to wander into classified territory in discussions of nuclear terrorism, or at least into the classified territory relating to the design of nuclear weapons. Once upon a time, the National Weapons Laboratories and others used to (and maybe still do) come up with silly menageries of “threat objects” to “help” the radiation portal operators focus in on what to look for. Of course, the radiation signature of such “threat objects” can vary over a wide range depending on what kind of shielding and other objects surround it, and even in which direction the “threat object” is pointing when it passes through the portal. Other than that, there are an infinite variety of potentially lethal weapon configurations that are quite different from those in whatever menagerie you happen to consult.

Look, the “threat object” is SNM. That’s what terrorists have to have to assemble a nuclear device, and that’s what you have to look for, period. Do they have to smuggle it in 4 kg or 25 kg chunks? No! Depending on how patient they are, they can smuggle in bits as small as they please, and then assemble them at the target. Would it be hard for them to assemble a weapon at the target. Well, much has been said about the great technical virtuosity terrorists must have to assemble a nuclear weapon. Here’s the reality:

1. Take two chunks of SNM, well separated, that, when combined, form a critical mass.
2. Put one of the chunks on the ground.
3. Climb up a medium size step ladder with the other chunk.
4. Take careful aim.
5. Drop the chunk you’re carrying on top of the other chunk.

Not exactly rocket science, is it? Now, this admittedly rather crude nuclear weapon isn’t going to outperform Fat Man, but, before the critical mass you’ve just created disassembles because of its own energy release, it will create a radioactive mess, paralyze all economic activity for a while in the surrounding area, and have a huge psychological impact. That may be just the result that potential terrorists have in mind. Why sacrifice the good will of potential sympathizers and collaborators by vaporizing hundreds of thousands of people? Why risk getting caught with the SNM while you try to figure out how to put together a high yield weapon? Furthermore, to assemble such a weapon at the target, you don’t have to bring in all the SNM at once. You can transport it in arbitrarily small chunks.

In a word, anyone who gains possession of SNM to begin with will not be deterred or stopped by radiation portals. In the first place, there’s no need whatsoever for them to go through the portal to begin with. However, if they insist on taking risks, they can spoof the radiation detectors by surrounding the SNM with appropriate shielding, or putting it next to a medical radioisotope or other innocent radiating material, or the SNM can be carried through in small enough bits to avoid detection.

The ineffectiveness of radiation portals will become increasingly obvious as more and more nuclear smugglers are caught. I an not aware of a single incident to date in which SNM smugglers were stopped by radiation detectors. The ones that have been caught tend not to be top drawer professional smugglers, but unsophisticated crooks who happened to have access for one reason or another. They were stopped, not by radiation detectors, but by good intelligence and police work. I suspect this pattern will continue into the future.

Does all this mean that all our attempts to detect illicit radioactive materials are a waste of time and money? I think not. In the first place, SNM is not the only kind of radioactive material the portals can detect. They have successfully detected scrap metal contaminated with radioactive waste, commercial radioisotopes without proper documentation, etc. As we build more of them, and devote more funding to their development, radiation detectors will become better and cheaper, perhaps to the point that a more effective detection strategy becomes feasible. Then, of course, there is a political side of the question to consider. If a smuggled nuclear device really does go off in a US city, how would you assess the chances of reelection of an Administration that had made a deliberate decision to discontinue funding of radiation portals?

The North Korean Nuke: Design for Delivery?

North and South Korea at Night

“If they had gone with the “fail safe” WWII design, it would probably mean it was too heavy to mount on a missile. They would be making a political bomb that would undoubtedly use a lot of high explosive to ensure it got a good compression of the plutonium pit. The 4 KT bomb, however, might very well fit on a DPRK missile. If they have stayed with this design, it probably indicates that weaponizing it is even more important than ensuring a successful test.”

Here’s something appeared in the UK’s “Guardian” a year ago that adds plausibility to that conjecture:

“Blueprints for a sophisticated and compact nuclear warhead have been found in the computers of the world’s most notorious nuclear-smuggling racket, according to a leading US researcher.

“The digital designs, found in heavily encrypted computer files in Switzerland, are believed to be in the possession of the US authorities and of the International Atomic Energy Agency, in Vienna, but investigators fear they could have been extensively copied and sold to “rogue” states via the nuclear black market.

“David Albright, a physicist, former UN weapons inspector and authority on the nuclear smuggling ring run by the Pakistani metallurgist Abdul Qadeer Khan, said the “construction plans” included previously undisclosed designs for a compact warhead that could fit on Iran’s (or North Korea’s, ed.) medium-range ballistic missiles.”

Read the whole thing. It begs the question of how we should respond if the North Korean leadership really is crazy enough to hit us, or one of our allies, with a weaponized nuke. Annihilate a population of slaves for the crimes of their leaders? We were ready to do that in the Cold War. Twenty years later, do we still really need to kill 10 or 20 million innocent Koreans to “make an example?” I’d hate to have to make that decision, because the answer may be yes.

Iran, Nuclear Weapons, and the “Hiroshima Fallacy”

A while back, I posted an article over at Davids Medienkritik about the “Hiroshima fallacy,” the notion that an effective nuclear weapon must necessarily have a yield approaching that of the device dropped on Hiroshima. This assumption is, of course, absurd. For example, all a terrorist needs to do to have a highly effective nuclear device is to drop one chunk of fissile material on top of another to form a critical mass. Whether it explodes or not is a moot point. It will certainly produce a radioactive mess, likely to cost millions if not billions to decontaminate. A few bloggers noticed (for example, here and here), but, in general, outside of a few people who know better, when it comes to nuclear proliferation, the world continues to keep its collective head deeply buried in the sand.

According to the conventional wisdom, a nuclear weapon is an extremely complicated device, requiring technological and scientific skill, not to mention economic infrastructure, only available to a nation state. In fact, the only thing that needs to be available is special nuclear material (SNM), typically in the form of either highly enriched uranium (HEU) or weapons grade plutonium. Whether or not Iran is really seeking to acquire nuclear weapons or not, its nuclear program must be seen in that context.

There is an interesting article on the subject over at Wikipedia, although, as usual, it is subject to change from day to day depending on the political predilections of the last one to post. It appears that, as this post is written, many of the incorrigibly optimistic are convinced that Iran is not enriching uranium beyond the level required for the production of nuclear power, and, therefore, poses no nuclear threat. Unfortunately, once one of those nuclear reactors is run for a relatively short period, it produces enough plutonium to produce a bomb, and no high-tech centrifuges are needed to separate it. All it takes is someone with a reasonalble level of skill as a chemist.

As in the case of North Korea, I have no brilliant suggestions about how to deal with the Iranian threat or the problem of proliferation in general. I merely point out that the problem is growing worse, that tons of SNM are out there, and that, eventually, enough of it will get in the wrong hands to make a bomb. Whether the “wrong hands” are those of a rogue nation or a terrorist organization, the result will be as devastating as it is inevitable. It is merely a question of when.

Quote for the Day: J. Robert Oppenheimer

“Now, I am become Death, the destroyer of worlds.”

The North Korean Nuclear Test: Blogs beat the MSM hands down

“Layers of editors” didn’t seem to help the traditional media much in their reporting about the recent North Korean nuke test. The bloggers beat them hands down in both accuracy and depth about the story. No wonder they’re losing audience. Take, for example, reporting on the yield of the weapon. In the US, CNN and MSNBC were typical of MSM outlets that seized on the early Russian estimates that the yield of the device was 10 to 20 kilotons. European outlets such as the Guardian followed suit. Radio reports typically compared the weapon to the one dropped on Nagasaki. Bloggers reporting on the test at nearly the same time were much more cautious – and accurate. See, for example, ArmsControlWonk and the FAS’ Security Blog. In spite of the dubious information floating around, a lot of people seem to be cocksure they know just what to do about the situation. As usual, the surefire nostrums vary considerably depending on whether one occupies a place on the left, middle, or right of the political spectrum.

The situation is very complex, and there are serious objections to all the simplistic solutions that their proponents seldom take into account. In fact, there may be no elegant solution to the problem. The Japanese grossly miscalculated the response of the United States to Pearl Harbor, expecting us to tire of an expensive naval war after a couple of years and let them have their way in Asia, after the fashion of the Russians in 1904-5. However, even the Japanese war party of the 20’s and 30’s was positively sober in its estimate of the world situation compared to the leadership of North Korea. We are dealing with a volatile, irrational enemy, and there are no perfect solutions to this problem. One thing is certain. When the inevitable happens, and a nuclear attack occurs, many attitudes will be adjusted. Nuclear weapons have not been used in anger for more than 60 years. They will, however, certainly be used again. The only question is when, and how. The time is probably nearer than we think, because all that’s needed is for someone or some entity, whether a terrorist organization or a nation state, to 1) be willing to pull the nuclear trigger, and 2) to acquire sufficient Special Nuclear Material (plutonium or enriched uranium) to build a bomb. And, make no mistake about it, once they have the SNM, they will have the bomb.

Why the Reliable Replacement Warhead (RRW) is a Bad Idea

The incomparable Instapundit recently linked a TNR article on the demise of the Reliable Replacement Warhead (RRW) Program. According to TNR, ““Obama’s new budget plan includes a little-noted sea change in U.S. nuclear policy, and a step towards his vision of a denuclearized world. It provides no funding for the Reliable Replacement Warhead program, created to design a new generation of long-lasting nuclear weapons that don’t need to be tested. (The military is worried that a nuclear test moratorium in effect since 1992 might endanger the reliability of an aging US arsenal.) But this spring Obama issued a bold call for a world free of nuclear weapons, and part of that vision entails leading by example. . . . Obama’s budget kills the National Nuclear Security Administration program once and for all.” Glenn’s post included the sour rejoinder, “So, a question: If Obama were trying to wreck America as a superpower, what would he be doing differently?” It’s remarkable how few blogs have weighed in on this issue. Miscellaneous specimens of web chatter can be found here, here, here, and here., and the “orthodox” arguments in favor may be found here. I’m anything but sanguine about Obama’s grasp of national security issues. However, for reasons that probably never occurred to the POTUS, I think the redoubtable Glenn is wrong this time.

Here’s why. There has been a strong contingent at the National Nuclear Security Administration (NNSA), at the National Weapons Laboratories, and in the military, who are either in favor of a resumption of nuclear testing or have considered such a resumption inevitable since the time that the RRW was but a twinkle in some designer’s eye. Why? One can only speculate. Perhaps it’s because the National Weapons Laboratories want to survive, and it has not failed to occur to those who have the interests of the labs at heart that a return to nuclear testing would substantially enhance their national relevance. It would also help to solve their demographic problem. It’s hard to attract top drawer scientists with the prospect of acting as custodians for an aging stockpile of nuclear weapons. Regardless, it has been a tacit assumption among a good number of folks with connections of one kind or another to the national weapons program that we would resume nuclear testing, and better sooner than later.

Enter the RRW. According to the prevailing narrative, the RRW can be built without the slightest need for a return to testing. This is nonsense. Ten years ago, any designer worth his salt would have reacted with scorn to such a suggestion. Today, they remain mum, not because they are completely confident in the “full physics” nuclear weapons codes that NNSA’s Advanced Simulation and Computing (ASC) program is turning out, but because they don’t want to rock the boat. Believe me, if the RRW were actually built, they would find reasons by the dump truck full to test it. The pressure to do so would become virtually irresistable. However, a return to testing would be a very bad idea for the US.

Why? Our nuclear weapons program is mature, and our mastery of the relevant physics is unsurpassed. Is it reasonable to give the rest of the world a chance to catch up with us? Is it reasonable to abdicate the moral high ground, giving nuclear wannabe’s like Iran a perfect excuse to pursue their nuclear ambitions “full speed ahead?” Is it reasonable to increase the nuclear danger by promoting the resumption of testing by others, and the proliferation of nuclear armed states. I think not.

What would we really gain by building an RRW? Very little! The idea that the weapons in our arsenal must, inevitably, become “unsafe,” or “unreliable” are nonsense. Our weapons are robust, and any enemy assuming the contrary would be making a very unfortunate miscalculation.

In a word, then, the Obama administration has managed to blunder into a good decision on the RRW. Let’s leave it at that and worry about more pressing matters.