For decades, scientists have worked toward the dream of harnessing a fusion reaction. Fusion, which involves the joining together of two light atomic nuclei, should produce much more energy and much less radioactive waste than the current nuclear reactors which are based on fission (splitting) of uranium. Unfortunately, making a controlled fusion reaction has proved a lot harder than many people would have thought. For years, the joke has circulated through energy circles: fusion is the power source of the future, and it always will be. Things are not completely bleak on the fusion front. Just last week, France was selected as the site for a massive international effort to build the first practical fusion reactor. If all goes as plans, the reactor could be operational by the end of the decade. Maybe.
But this diary isn’t about fusion. It’s about that other kind of nuclear reaction, the kind in use around the world today — fission. It’s about how we might be able to make fission not only cleaner, but 100% safe.
Commercial reactors run on uranium.
That’s the way it’s been since the first commercial reactors were started up in the 1950’s. Put in uranium, extract an admix of uranium, plutonium, and assorted byproducts.
Only the reasons for using uranium don’t all have to do with producing power. In fact, reactors were designed around uranium for a very different reason.
Uranium was picked, not because it was the cleanest or safest possible fuel, but because it was both dirty and dangerous. Its waste products include everything you need to start up your own Cold War era bomb assembly line – which is exactly why we’re so antsy about Iran having nuclear reactors based on this fuel. Building uranium reactors was easy, since the reaction is self-sustaining, which is exactly why it’s also easy to have a reaction run out of control.
Traditional power plants, which involve fuel rods stuffed with pellets of uranium regulated by various means, had some degree of inherent instability. Some of these designs are worse than others (i.e. Chernobyl). Newer power plant designs, like the Pebble Bed Reactor enclose the uranium fuel in small “pebbles” that make it nearly impossible for the reactor to ever run out of control.
But what if there was another choice? What if you didn’t run your fission reactors on uranium at all? What if you ran them on another element, one that’s much more common, produces less overall waste, and whose use creates much less of the plutonium suitable for making nuclear weapons? What if you ran reactors on thorium?
Why throrium? First of all, it’s a lot more abundant than uranium.
40x as much energy available from thorium, and thorium is not only available in the United States (which has a decent supply of uranium), but also in countries where uranium is much more scarce. Further, since thorium can’t be as easily refined to make nuclear weapons, it can be shipped around the world with less concern.
If we were running our reactors on thorium, we would produce much less waste. If Iran was running its reactors on thorium, we’d be a lot less concerned about them turning spent fuel into weapons. So why don’t we run on thorium?
Well, there’s a problem.
Oh. That sounds pretty bad, huh? A reaction that can’t be sustained is back into fusion land – looks good, but not very practical. However, what looks like a problem on the surface, is actually another benefit of using thorium as a fuel. It is possible to sustain a reaction in a thorium-based reactor, but to do so you have to stimulate it using an “Accelerator Driven System,” or ADS. In an ADS, a high energy accelerator is used to spawn additional neutrons through a process called “spallation”. This does make sustaining the reaction more complicated, but it has a big advantage: turn off the ADS, and the reaction stops. A “subcritical,” ADS-based reactor can never run out of control.
So thorium is more abundant than uranium, a reactor based on thorium makes it much tougher to make weapons, and a thorium reactor can never “go Chernobyl.” How about nuclear waste?
There’s one other big advantage of using an ADS system. With it, you can “burn” some of the waste products (in this case, the actinides) down to stable isotopes, eliminating a good percentage of the waste. It’s not an absolute positive, as the short-term result is even more energetic radioactive isotopes, but over a longer period, the resulting waste should be less radioactive than uranium ore.
With all these advantages, thorium has finally started to get some attention over the last few years. There’s been some significant research in both the United States and Russia, and for nearly a decade, India has been running a research reactor on uranium-233 created from thorium fuel. Now India is getting ready to make the next step. They’re going to test their own ADS-based, thorium reactor. They have high hopes, and so does the thorium mining industry.
The anticipated surge in demand for thorium has led at least one mining company to begin buying as many thorium deposits and stockpiles as it can.
“We feel that it’s inevitable that the U.S. and other countries in the world — India of course — will exclusively use thorium in the future,” said Novastar Director of Strategic Planning Seth Shaw.
How likely is Shaw’s “we all move to thorium” scenario? Unfortunately, none too likely — at least, not in the short term. The current nuclear industry is entrenched in the uranium business. From mining to refining to the reactor, uranium is what they know. Market prices currently put the cost of thorium only slightly below uranium, not enough to cause any major company to consider making the switch.
However, there’s one factor overlooked in the current pricing – the cost of waste disposal.
Currently, waste fees are calculated as a fraction of the cost of the electricity that is produced by the fuel. Kazimi proposes charging by the volume of plutonium instead, so as to discourage its creation.
Current waste fees are calculated only on the output of the plant, with no regard to the toxicity of the waste. If waste fees were calculated so that the creation of plutonium was discouraged, thorium would suddenly look a lot more attractive to the US industry.
Changing this fee structure is just one of the many items that should be involved in a effective national energy policy. It’s one of those minor things, easy to overlook in the glut of new tax breaks for oil companies, that might just lead us to safer power plants.
So brilliant it will never happen.
But I appreciate having your thoughtful essay about the possibility.
Actually, one of our clients (I work in an IP lawfirm) is working on just this sort of technology. Obviously for privacy reasons, I cannot say more, but I would absolutely not rule out the possibilities of cleaner and safer nuclear reactors using alternate fuels and systems.
In case you need a break from the ugliness of the last days, here’s something a little more esoteric to think about. Plus, this one plays into the items in my upcoming “what we should lobby for in the energy bill” diary.
I suspect I’ll cross-post this one over at kos.
I learnt new stuff – which is often the case with your diaries!
Would you consider posting this over at European Tribune as well? Thanks.
I’m going to post a diary tomorrow on a related technology, The Energy Amplifier that was invented by an old grad school prof of mine (now at CERN in Geneva). It’s really the same thing but there is a version that is designed explicitly to transmute transuranics and fission fragments into short-lived nuclides. Makes energy and cleans up the mess at the same time! Slices and dices too 🙂
This will hopefully answer some of the objections raised downthread.
Thanks for bringing thorium up.
While it’s true that we could probably use an accelerated thorium reactor, as for about 5 years ago I wasn’t aware of one in operation or testing.
It’s good to hear that India has expressed an interest in developing the technology. I’ll be really happy if we can get to the point of reliable thorium reactors (which, coincidentally are better to produce industrial irridium and cobalt-45 radiography equipment, and the DU to shield it).
Thanks.
I’m glad you raised this. However, I’m not optimistic. The extra toxicity of uranium plants seems to have an appeal to the Dominionists who seem eager to bring on end times.
Okay, less cynical response: It would take a huge investment. I’d like to think that some of these energy companies were smart enough to see that this could be one huge money making export for the US, thorium plant technology. It’s not ideal, but it has the advantage over solar and wind power in being able to provide a lot of energy from relatively limited real estate.
But my guess is that these fat cats won’t want to learn anything new. They’re rigged for poison, and poison is what they want to do to make money. Their assurances of safety are hollow when we’re talking a half life of tens of thousands of years. No nation has lasted anywhere near as long, let alone a company. Who are they kidding? Us. And our representatives are buying it.
But I hold out hope that not everyone is so stupid and greedy as to destroy the Earth just to make more money.
Seems like common sense to me that if Australia and/or India have plentiful supplies of thorium, their governments at least would want to investigate and invest in this technology, not only for use at home but for export as the oil runs out. Perhaps in conjunction with nations like Japan and France that also have reasons to be interested.
And there are plenty of ex-Soviet nuclear experts looking for work in the field that probably would be happy to get involved with whoever was starting a project like this.
Other nations are not totally controlled by out multinationals, thank goodness.
Thank you Thank you Thank you.
This is the first I have heard of this. I guess that says something, either about me, or about the media and entrenched power structures. All of a sudden I am no longer deeply conflicted about nuclear energy. I could be bhind this 100% with the shorter half-life (though consequently more intensely radioactive in the short-term) isotope waste.
Can the “burning” process also be used to generate energy?
Also, I’m moving to Australia, so I’ll agitate for this when I’m there!
Thanks, DT
still unsafe
the main problem being that Thorium 233 degrades into Uranium 233
Thorium 233
via Nuclear France
The EPA on Exposure to Alpha Emitters
and on Gamma radiation
industry being what it is waste disposal costs would continue to be externalized by the producers and absorbed by the general poulation while being subsidized by the government.
I am not sure that any new nuclear options are options (unless fusion actually pans out, though I have my reservations)
I’m glad you posted this. What’s important is being realistic about nuclear power. Pebbles, thorium, whatever. No more magical thinking. I don’t know anything but what I saw on Wired.com, and that’s not exactly Scientific American (though I love it).
Thank you for your diary.
Still, the history of nuclear science–(never mind the nuclear industry, which operates on lying!)–has been replete with cases of insufficient consideration of externalities. This has been true since day one, and did not change when Madame Curie died from radiation exposure accumulated in her own lab. Although safety standards have indeed improved, they continue to lag behind available health information, information whose whole history has consistently been that the dangers are worse than we thought.
The only reasonable yardstick for radiation exposure is earth background. This is one to two orders of magnitude lower than what we allow in most of our health standards. Are we stupid, or what?
Nuclear waste is not like other waste. Chemical waste can always be, in principle, cleaned up or neutralized, even if it is frightfully expensive in a given situation. But the nuclear waste we create now will exist for as long as their are humans: It is a burden we place now on all are future descendents. How lightly we place this burden on them! What in the world are we thinking? Do we really hate them that much?
Probably.
But for my part, it makes me think twice, or more. It is good to know there is a nuclear possibility that is not as openly malign as the processes we currently use. But there remains much to consider before it can be in any reasonable sense considered safe.