The downside of the MSR configuration is that it's way harder to build, and involves some maybe-not-entirely-solved problems around corrosion resistance, since the salts in question tend to be pretty reactive.
Advanced fuelS for Generation IV reActors: Reprocessing and Dissolution
Apparently there's also this talk by Kirk Sorensen, but I haven't seen that one yet.
* (again. It did reach real scale in post-WWII France among other places)
> One or two 233U bombs were tested in the Nevada desert during the 1950s and, perhaps ominously, another was detonated by India in the late 1990s. [...] intense gamma radiation 233U produces fries the triggering circuitry
...this only shows that military use is possible! For someone less concerned about safety and more concerned about having a nuclear weapon at all costs, it might be even easier. That triggering circuitry is definitely a solvable problem... brrrrrr
Do a Google search for the headline and click on the article that way. Or forge the 'Referer' header.
This more or less sold me on the idea years ago.
The idea of the liquid fueled reactors is that you can easily change the fuel composition, ideally constantly reprocessing the fuel of contaminates, while letting the unburned fuel stay in place. This would drastically reduce the amount of waste generated (by orders of magnitude), and the 'unburnable' waste left over actually has some uses of its own (molybdenum 99 and bismuth 213).
What hasn't been solved is the effects of of all our coal, gas, and oil usage that could be replaced by nuclear power. It makes all the sense in the world to be finding ways we can widely and safely deploy nuclear power worldwide to replace coal and gas power plants. Generating clean electricity is a requisite for wide spread electric or hydrogen cars to stop burning gasoline.
If you believe that coal and gas burning is bad for the environment, then we need nuclear power urgently and widely, energy needs are only going to go up and the only alternative to nuclear is burning more fossil fuels. I find it absolutely absurd that people worry more about nuclear waste than atmosphere pollution currently happening. I think we could store a few hundred years of nuclear waste on Antarctica til technology figures out what to do with it, even if that's just shooting it into the sun. I choose safely storing nuclear waste for the future to deal with over continuing to burn billions of tons of coal and gas each year which is actively killing about a million people per year. (WHO 2008)
Thus, solving the problem once and for all.
ONCE AND FOR ALL!
The waste in conventional reactors are of two types, fission procucts and higher actinides. The fision products are the result of splitted uranium atoms. These are intensively radioactive, with halflives from milliseconds to about 30 years.
Then there are higher actinides, with halflives up to tens of thousands of years. These are less radioactive, but still radioactive enough that they have to be safely stored. This storage must be safe for hundred of thousands of years, something that it is hard to guarantee. Fision products only need to be stored for about 600-800 years before they are no more radioactive than uranium ore. Thorium rectors produce virtually no higher actinides, so it is easier to find storage that is safe for the period it must stay out of reach. It is also less volume of the waste (but more concentrated, as the amount of radioactivity is about the same), since the fission products are not mixed with U238 as in conventional reactors. This means that less storage is needed, which also makes it easier to handle.
And the currently used alternatives (coal) produces way more waste (whole mountains of slightly radioactive, and slightly toxic dust leftovers from coal extraction build up near coal mines).
(Don't vote me up for this either. Dismissive first posts are another HN trope, so in this regard I'm as guilty as The Economist.)
What makes you think The Economist is interested in probing the nerdosphere? Would Tesla, Apple, etc., be more effective? For sure, the '... adoption is 10 years away' thing is funny. Makes me reminisce for Popular Science.
If I were to guess; they are advertising where their technological sympathies lie. It is more about managing their brand than probing an audience.
That was a pretty fun one: http://en.wikipedia.org/wiki/Project_Pluto
If we hadn't canceled it we'd be colonizing the Solar System by now.
... speaking of flying nuclear reactors
"Meanwhile, at the Pentagon, Pluto's sponsors were having second thoughts about the project. Since the missile would be launched from U.S. territory and had to fly low over America's allies in order to avoid detection on its way to the Soviet Union, some military planners began to wonder if it might not be almost as much a threat to the allies. Even before it began dropping bombs on our enemies Pluto would have deafened, flattened, and irradiated our friends. (The noise level on the ground as Pluto went by overhead was expected to be about 150 decibels; by comparison, the Saturn V rocket, which sent astronauts to the moon, produced 200 decibels at full thrust.) Ruptured eardrums, of course, would have been the least of your problems if you were unlucky enough to be underneath the unshielded reactor when it went by, literally roasting chickens in the barnyard."
Of course I was down-voted: HN's readership doesn't like to be told that it's a trivially exploitable source of clicks.