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Bill Gates To Help China Build Traveling Wave Nuclear Reactor
First time accepted submitter BabaChazz writes "Microsoft Corp. co-founder Bill Gates says he is in discussions with China to jointly develop a new kind of nuclear reactor. During a talk at China's Ministry of Science & Technology Wednesday, the billionaire said: 'The idea is to be very low cost, very safe and generate very little waste.' Gates backs Washington-based TerraPower, which is developing a nuclear reactor that can run on depleted uranium."
Just wait, China !
Bill Gate will give you Blue Screen of Nuclear Death !!
Muchas Gracias, Señor Edward Snowden !
Too bad he's prohibited from doing something like this in the US. If it weren't for ill-rational fears of nuclear power the R&D would be done in the US.
"Ubuntu" -- an African word, meaning "Slackware is too hard for me". - stolen from Dan C alt.os.linux.slackware
China is one of the largest CO2 polluters in the world. Traveling wave reactors are known to be incredibly clean and safe. If you give the Chinese abundant safe and clean energy, this is going to really help the global warming problem.
The reason traveling wave reactors were never used, even though the technology has been know for half a century, is that they produce no waste that is useful to making nuclear weapons. That is only reason why all nuclear power nations wanted the more dangerous reactors that ran on uranium and plutonium fission.
But modernizing the safer, non-weaponizable form of nuclear power is a great way to go.
In Japan they no longer have the honor they once had in their leadership so the responsible ones do not kill themselves anymore
I call bullshit.
Are you seriously going to sit there and tell me that suicide is the honorable response to a fuck-up?
The fuck it is. The honorable response to a fuck-up is devoting your life to cleaning it up, until either you fix it or you die of natural causes.
Suicide is a coward's way out, it passes the problem to the next guy and somehow through the power of death magically absolves you of your sin.
I needed a sig so people would know who I am, but I was too drunk to make something witty, so you get this instead.
The ultimate question for all reactors is what they leave behind.
They can't help leaving behind fission products (that's where they get their energy from), which isn't too much of a problem, as it takes only about 300 years for them to decay to levels of radiotoxicity of natural uranium in equilibrium with its decay products.They will leave behind some Uranium, but this can still be used in other reactors.
The problem is mainly residual Plutonium, Americium and other elements, with half-lives of several thousand or tens of thousands of years, which require hundreds of thousands of years to decay to such levels. (Because of the very damaging high energy alpha decay, rather than lower energy and much less damaging beta and gamma decays.)
On the one hand non-fissle transuranic elements capture neutrons and interfere with the chain reaction, on the other hand capturing neutrons either splits them or eventually transmutes them into fissle elements. This turns them into fission products, which we can handle with reasonable confidence. The question now is: does the travelling wave in the travelling wave reactor provide enough neutrons to transmute and split the transuranic elements it breeds, such that the reactor as a whole reaches a stable equilibrium before the end of its operating time? Conventional reactors don't, because the chain reaction is stopped for lack of neutrons long before a stable equilibrium is achieved. Most breeder reactors do, but it depends a lot on how tight the neutron economy of the particular reactor is. And afaik (correct me if you know better or have access to specifications), the neutron economy of the travelling wave reactor is rather tight and might well be possible, that the wave leaves ever more transuranics in its wake as it moves, without ever reaching an equilibrium over the whole of the reactor.
Why is reaching a stable equilibrium before the end of operation enough? In this case you can add some additional transuranics at the start of operation and still reach the same equilibrium at the end of operation. If the amount you can add at the start (and still reach equilibrium) is larger than the amount left at the end of operation, you effectively reduced the total amount. Given that, you effectively solved the long-term problem of transuranic waste, by limiting its amount and eventually burning it.
The question is, can the travelling wave reactor do that or not? (There are other options ex post, but it is always best to not let the problem exist in the first place rather than dealing with it later.)
In the new design, the reactions all take place near the reactor's center instead of starting at one end and moving to the other. To start, uranium 235 fuel rods are arranged in the center of the reactor. Surrounding these rods are ones made up of uranium 238. As the nuclear reactions proceed, the uranium 238 rods closest to the core are the first to be converted into plutonium, which is then used up in fission reactions that produce yet more plutonium in nearby fuel rods. As the innermost fuel rods are used up, they're taken out of the center using a remote-controlled mechanical device and moved to the periphery of the reactor. The remaining uranium 238 rods—including those that were close enough to the center that some of the uranium has been converted to plutonium—are then shuffled toward the center to take the place of the spent fuel.
Currently there is no known material that could be used to encase the fuel rods in -- they need to survive radiation exposure for decades without expanding.
Suicide is not a coward's way out. Yes, it passes the buck, but what needs to happen in someone's head which allows them to go against every instinct every living thing has had for billions of years - survival - has to be pretty god-damned tough to go through.
Don't judge until you try it yourself.
Thorium itself is not a nuclear fuel, it's what is called a fertile material. When bombarded with neutrons it produces Uranium-233 , which is an excellent nuclear fuel, and most certainly usable in a nuclear weapon. The process is very similar to how Plutonium-239 can be made by bombarding Uranium-238 with neutrons.
The main reason people don't use Thorium and U-233 for making bombs is that the U-233 tends to become contaminated with highly radioactive isotopes, making it difficult to handle. In principle you can avoid this by using a more elaborate irradiation and separation technique, but it's just easier to use Uranium-bred Plutonium instead.
To summarise:
Thorium-232 and Uranium-238 are not on their own useful for nuclear fuel or weapons. However, they can be turned into fissile material by bombarding them with neutrons.
In this way Th-232 can be turned into U-233
Whereas U-238 can be turned into Pu-239.
Both U-233 and Pu-239 can be used for weapons, but it is easier to keep the radioactivity of the Pu-239 low.
Hence it is easier ( and cheaper ), to use Uranium fuelled reactors to make a bomb than to use Thorium.