Imagine how the nuclear energy debate might differ if the fuel was abundant and distributed across the world; if there was no real possibility of creating weapons-grade material as part of the process; if the waste remained toxic for hundreds rather than thousands of years; and if the power stations were small and presented no risk of massive explosions.Though apparently molten-salt reactors can run not just on thorium, but nuclear waste.
What you're imagining could fairly soon be reality judging from a little-noticed development in China last month.
While nearly all current nuclear reactors run on uranium, the radioactive element thorium is recognized as a safer, cleaner and more abundant alternative fuel. Thorium is particularly well-suited for use in molten-salt reactors, or MSRs. Nuclear reactions take place inside a fluid core rather than solid fuel rods, and there’s no risk of meltdown.A breeder reactor is one in which isotopes present in the fuel that do not undergo fission are converted by neutron capture to isotopes that do undergo fission. Thorium reactors are breeder reactors as fissile thorium isotopes are minor so non fissile thorium must be continuously converted to uranium.
In addition to their safety, MSRs can consume various nuclear-fuel types, including existing stocks of nuclear waste. Their byproducts are unsuitable for making weapons of any type. They can also operate as breeders, producing more fuel than they consume.
Salt reactors are also more fail-safe.
If it begins to overheat, a little plug melts and the salts drain into a pan.And thorium is extremely abundant:
The earth’s crust holds 80 years of uranium at expected usage rates, he said. Thorium is as common as lead. America has buried tons as a by-product of rare earth metals mining. Norway has so much that Oslo is planning a post-oil era where thorium might drive the country’s next great phase of wealth. Even Britain has seams in Wales and in the granite cliffs of Cornwall. Almost all the mineral is usable as fuel, compared to 0.7pc of uranium. There is enough to power civilization for thousands of years.So perhaps cleaner cheaper nuclear energy is on the horizon? Personally I am keen to see hydrogen fusion.
I've been watching for news on Thorium/Salt reactors for awhile. It's hard to fathom why somebody won't go there (apparently aside from the Chinese now). As I understand it the technology has been known for 60 years or so. Oak Ridge ran them in the 60's and 70's. I understand that they originally were apparently not as desired because they didn't result in weapons grade by-products but in these days it seems like they could benefit us significantly. Makes me wonder why the powers that be make the decisions they do and what their real motivations are.
ReplyDeleteVery interesting. I didn't know about this. Thanks.
ReplyDeletemike, I don't know enough to answer why, though there may be technical issues that haven't been fully ironed out (due to lack of research thus far).
ReplyDeleteCraig, neither did I till recently. Though I knew about the concept of breeder reactors. We don't have any reactors here.