More details on the experiment sequence: https://public.ornl.gov/conferences/MSR2016/docs/Presentatio...
This is not actually a reactor test because the thorium-bearing salt does not attain criticality. It's a sequence of materials tests using thorium-containing salt mixtures in small crucibles inside the conventionally fueled High Flux Reactor (https://ec.europa.eu/jrc/en/research-facility/high-flux-reac...).
The experiments rely on neutrons from the High Flux Reactor to induce nuclear reactions in the thorium-bearing salt mixtures. However, the experiments will be useful in validating materials behavior for possible future molten salt reactors because it combines realistic thermal, chemical, and radiation stresses.
If this structure is lacking, it'll be obvious to sentiment analysis, that there are too much free floating statement, and the article either requires too much outside knowledge (in field expertise), or it's just gossip.
And of course it can be "easily" estimated how novel the statement is, what quality the sources and support are, and so on.
I seem to recall a similar weekly service for HN but I can't recall the name of it.
Maybe http://www.hackernewsletter.com/ but that's an email.
> Pasting n-gate content or generally talking about n-gate on "Hacker" "News" is a violation of the Prime Directive.
In other words, they want to publish their rants, but are unwilling to discuss their views with anyone, not even the very people they are criticizing. This may be a valid (although insane) approach for a blog, but somewhat contradicts their stated goal:
> The purpose of n-gate is to be a remote island of contemptuous sanity in a sea of ridiculous webshit.
"Reactor" evokes "Nuclear Reactor". For many people, "nuclear reactor" is a deeply loaded term. Likewise "Thorium" (and other words that end in "-ium") sounds dangerously like "plutonium" and "uranium".
It doesn't matter how much better/safer this technology is. Don't expect the public to respond positively when we use those words. There's too much knee jerk, "no nukes!" baggage.
We should start calling these "salt power stations" or something else accurate, yet non-threatening. Otherwise, IMHO, it will be a steep uphill battle getting public and legislative support for building these things, regardless of their many benefits.
Honestly I consider focus on Thorium fuel itself to be an attempt to rebrand the much broader but equally capable advanced nuclear industry.
Mining Uranium ore does have a significant environmental impact. There have been leaks at plants; trace amounts of tritium has been found around breeder reactors like Watts Bar (and TVA has bought up more and more of the land around the area).
The waste, currently held on site at most plants, is another big issue. Engineers will tell you it's depleted and encased in half a meter of concrete that won't break down for tens of thousands of years. Some of these containers are already leaking. There have been several recent controversies recently on the Yukka Mountain facility.
While newer reactors may not have these problems, the fact is there are problems we weren't aware up that cropped up from our traditional Boiling/Pressurized Water Reactors that companies will not fess up to. That's why people are apprehensive.
I don't think that will go away unless someone discovered how to make Low Energy Nuclear Reactions (LENRs) viable .. which would also involve understanding how/why they world, and getting them to work consistently (which no one has).
> Mining Uranium ore does have a significant environmental impact.
I'm glad you bring that up. To actually understand how much of an impact we need to compare it to things. The human mind isn't good at putting into perspective raw numbers when they are that large, it's just "a lot". When you include the mining of both solar and uranium plants, you actually get around the same total environmental impact. I make this comparison because I've never heard anyone complain about the switch to solar. When we compare to coal mining, fracking, or oil drilling, uranium is tiny. Or even comparing to computers and cell phones.
> The waste, currently held on site at most plants, is another big issue.
I carry a vial of tritium around in my pocket? Why? Because it glows and is a fun conversation. I have no worry about it irradiating my junk because it is a beta emitter that has low penetrating power (~6mm of air). The danger of tritium is soft tissue. So just don't drink it or rub it in your eyes. Granted a leak is more worrisome, but its danger is nowhere near that of the heavy elements. There will always be some waste, but nuclear has done a pretty good job compared to other energy sources because of the fear. Some fear is healthy, especially with this tech. But, again, we NEED Yucca Mountain. There's not much waste, but we should put it in the proper place.
> While newer reactors may not have these problems, the fact is there are problems we weren't aware up that cropped up...
You're discussing concerns about decades old technologies. Remember, that was the same era we were arguing over lead in gasoline, asbestos, and aerosols. Sure, we have problems today, but it isn't the same magnitude. No one in their right mind would shoot a nuclear waste container, or even put it in that small of a container anymore. Things have really changed in the last 50 years, and nuclear tech has been progressing in that time too.
>I don't think that will go away unless someone discovered how to make Low Energy Nuclear Reactions (LENRs) viable
Call it what it is, cold fusion. I'm not going to hold my breath on that one. But ITER and other fusion facilities are showing promising results. But fusion is not just a different ballpark from fission, it is a completely different game (energy and safety).
A cautionary tale about this flavor of argument.
I saw a panel of Boston city planners. They complained about still getting grief for the "original sin" (their phrase) of some really bad decision making (like Boston City Hall) in the 1960's and 70's. It was half a century ago they said. We're not like that anymore they said. They seemed quite miffed about it.
Then they later mentioned Boston's recent Big Dig, and some of its impacts. And the description was surprisingly distorted. Not even a defensive "none of the failure was our fault!", though that was implicit. But more, almost an obliviousness towards causality. And certainly no recognition that their brief description of their field's "no longer relevant" 1960's flaws, seemed to overlap quite a bit with failure postmortems of the Big Dig.
This combination of arguments was remarkably effective in trashing their perceived credibility.
Even coal which has long been the cheapest but dirty option is having trouble competing.
*with $2 Natural Gas
The solar/wind $23/MWh production tax credit is not really something that's easy for anyone to compete with, except natural gas. 
You're right that nuclear needs to get its costs down, especially to play in the west. We know it can be done because the French electrified nearly their entire grid with nukes in 10 years for reasonable costs, and the Koreans, bless their hearts, have been building Gen III plants at very reasonable prices. (Alas! their new president is riding an anti-nuclear platform.) With the recent Toshiba/Westinghouse issues regarding the US AP1000 plants, it's pretty unlikely to see any big new nukes anytime soon. But the world moves on and China is building lots of nukes.
Fukushima will be really expensive. Building tornado-hardened designs in tsunami zones does not pay off, so we should not do that. But building appropriately hardened designs is a pretty solid non-emitting solution. Nukes produce 65% of the carbon-free electricity in the USA right now; they're already our climate champions.
The big issues are keeping our construction, engineering, and regulatory agencies active with the subject material and with industry, and allowing saner reactor technologies into commercial use.
Fukishima was not far off from surviving that catastrophe as was. More robust training for emergency response would have avoided them pumping the water the wrong way, and something as simple as raising their backup generator a few meters off the ground would have done the trick.
More vitally, pushing techs into commercial production like thorium-salt reactors (among many others!), would provide failure modes that are INSANELY better than what we get from light water reactors. It's just about the most insane thing to do with radioactive power sources... surround them with something under pressure that violently expands and tries to go right to the atmosphere...
I think the tsunami zones should be fine for reactors, we just need to start with reactor designs that will thrive in failure. Your molten salts turning into rock and keeping themselves contained during a breach or flood, for example, is something that's highly amenable to disaster planning.
Even then, there was time to bring in backup generators, and they were brought - but idiotically the connectors were wrong and they couldn't be connected in time.
> Nukes produce 65% of the carbon-free electricity in the USA right now; they're already our climate champions.
And this is the reason I fight tooth and nail for it. If we're to meet our emission goals for 2050, we have to build more nuclear. A diversified portfolio of energy sources is key.
I think honesty will get you much further. Instead of making bold promises that everyone has heard before ("these are fail-safe", "unsinkable" etc.) just point at the radioactive dust emitted by coal plants instead. Or open pit mining for coal. Or CO2 emissions. Don't claim to be perfect, just better than the competition.
Oil, gas, and coal companies have known about climate change for decades, and it represents a threat to untold megabillions worth of profits and business. It is no coincidence they have been pushing anti-nuclear FUD, sponsoring hack research, pushing "green" blogs, NIMBY campaigns, and such for decades. Coordinated, professional, smear campaigns masquerading as environmental issues.
Leaked presentations and marketing materials have shown those companies have triangulated the issue quite simply: They cannot win on facts. They cannot convince everyone to keep fossil fueling it up on the merits of their argument. They can, however, cause enough confusion and knee-jerking to keep the "debate" about climate change open to paralyze political action. They have also pushed pie-in-the-sky green solutions which are superficially satisfying but fundamentally entrench their interests until we're past the point of no return. Push the starting line so far forward that we just have to give up.
That the "environmentalists" on the left have spent 20+ years pushing the strategic interests of Big Coal and Big Oil using their resources and bad science is the result of willful manipulation. That manipulation is a response to the threat of atomic energy and climate change legislation in light of our global infrastructure cycles.
That is to say: if you call fission "grandmas apple pie" it will be a very short time before we're all convinced that grandmas apple pie is dangerous, impractical, too expensive, poorly thought out, not scalable, not feasible, and impossible to do right. Forget what the stats say. Do not look at Ontario. Pretend France is not real. There will be blogs. There will be glossy signs. There will be "grassroots activism", tweet campaigns, and coordinated messaging about Big Grandma and the cancerous properties of Pie. The anti-GMO people will now be anti-grandma, too.
We are playing a game against well-connected oligopolists... We only get to win if we win. They get to win if they win, or if the clock runs out. So guess what the strategy is?
From the executive summary:
"In 6 out of 7 of the countries considered, public opinion has been growing more supportive of nuclear energy in the energy mix. The data show that countries where nuclear energy is already present have populations that are generally much more supportive of its use. They also show that these publics are generally better informed and more knowledgeable on nuclear issues and there is a clear positive correlation between knowledge and support."
Fusion is fine for now, but "fission" has already been chicken-littled :/
We should avoid names inspired by what amounts to political correctness, because people who see through the names may distrust us further.
However, I do appreciate your point, and I agree that it is a problem. I think the attitude, at least from young white collar professionals, is warming up to nuclear.
A LOT of people make decisions based on emotion. Then they cherry pick the facts (if any) that support the choice, and disregard the facts that oppose.
What I mean to say is if I were a politician, I would be more concerned with aligning myself with other politicians, scientists, and policy makers, than my constituents in the initial term. Those who are non-technical may be won over later and with other means.
You need initial popular buy-in to be elected, which is why populist policies will always do well.
First it is really awesome to see actual research experiments being done on the materials. This is a critical first step in understanding the underlying complexity of the problems and as the article points out it is really helpful to have a regulatory agency that is open to trying new things.
The second is this isn't a 'Thorium-Salt Reactor' it is 'parts that would go into parts that would make up such a reactor if the experiments indicate they will work.' A much less clickbaitey headline but such is 21st century journalism.
* a (ideally several) functioning research reactor
* an industrial prototype
* and finally a fully functional commercial plant
It's a step in the right direction, but the road is very long.
The Hastelloy family of super alloys is basically stainless steel without the steel and was proven in the Oak Ridge MSR experiment.
In 1977 Oak Ridge concluded :
Controlling the oxidation potential of the salt coupled with the
presence of chromium ions in the salt appears to be an effective means
of limiting tellurium embrittlement of Hastelloy N. However, further
studies are needed to assess the effects of longer exposure times and
to measure the interaction parameters for chromium and tellurium under
varying salt oxidation potentials.
> The idea is to stick to standard materials wherever possible and therefore the tubes are made of ordinary stainless steel. The suitability of steel remains to be determined. Corrosion may be a problem, and it is not yet know if it can be controlled by managing the salt chemistry. The high temperatures in MSRs might also be problematic, even if the pressure inside the system is low.
> For SALIENT-02, a different material mixture will be used that contains beryllium, forming a mixture also known as FliBe.
Further experiments will focus more on the interaction between the salt and the containment materials. Corrosion resistance is very important for those materials: they should be mechanically strong, and able to resist chemical corrosion and intense radiation. This corrosion resistance will be the next focus of the experiments with tests for 316 stainless steel, Hastelloy, the nickel alloy that ORNL used in the 1960s, and TZM – a titanium/zirconium/molybdenum alloy. Molybdenum has the potential to neutronically be much more attractive but there is no history of testing it at these temperatures.
And they have had the plans and motivation to build domestic reactors for the past two decades: https://en.wikipedia.org/wiki/India%27s_three-stage_nuclear_...
NSG membership keeps getting held up by someone or the other and would provide more energy security for India.
Looking at the wiki, it seems likely that outside forces might've been involved in the scandal.
What did I just read?
If the blue glow happens in your own eyeballs, you've probably just witnessed your own death sentence.
(charged particles traveling faster than) (the speed of light in water)
(charged particles traveling faster than the speed of light) (in water)
The particles are still moving slower than Relativity's limit, the speed of light in a vacuum.
#1: (charged particles traveling faster than the speed of light) in water
#2: charged particles traveling faster than (the speed of light in water)
Therefore, interpretation #1 doesn't make sense.
Maybe colloquially people refer to the speed of light in vacuum as "the speed of light", but again, that is technically incorrect.
*And more technically there's group and phase velocity which may or may not be equal.
Go to 10 physicists and say, "Is c the speed of light?" Odds are that most will say, "Yes." And while some may suggest more exact terminology, not one will fail to understand what you meant.
Furthermore at the subatomic level, light always goes at c. Even if you're in water. It has no other actual speed. Thanks to interactions between light and a medium it looks like photons go slower through the medium. But that's no different than the fact that current traveling through metal acts approximately like it is being carried by electrons of some other mass and velocity. (Or even, in some cases, like the absence of an election. This fact is critical to the operation of a transistor.) But "acts approximately like" and "is" are two different things.
I don't see a pump seal test in this experiment... does anyone know if a solution to the SRE meltdown problem is known at this point? Perhaps the LFT chemistry would not have the issue.
The best part of a molten salt fueled reactor is that in case of heat runaway the fuel would melt plugs and drain into separate containers. Essentially a meltdown would only require replacement of the plugs and refueling of the reactor to make it operational again.
Here are some reminders for everyone on the technical info about Thorium. First of all, Thorium is found in nature as a single isotope, Th-232, which is fertile like Uranium-238 (not fissile like U-235 or Plutonium-239). This means that you have to irradiate it first (using conventional fuel). Th-232 absorbs a neutron and becomes Protactinium-233, which naturally decays to Uranium-233, a fissile nuclide and good nuclear fuel. This is called breeding. Thorium is unique in that it can breed more fuel than it consumes using slow neutrons, whereas the Uranium-Plutonium breeder cycles require fast neutrons (which in turn require highly radiation-resistant materials, higher fissile inventory, and moderately exotic coolants like sodium metal or high-pressure gas). Any kind of breeder reactor (Th-U or U-Pu) can provide world-scale energy for hundreds of thousands of years using known resources and billions of years using uranium dissolved in seawater (not yet economical).
Great, so Thorium can do thermal breeding, so what? Well to actually breed in slow neutrons, you have to continuously remove neutron-absorbing fission products as they're created (lest they spoil the chain reaction), so you really can only do this with fluid fuel. This leads to an interesting reactor design called the Molten Salt Reactor (MSR). Fun facts about this kind of reactor are that it can run at high temperatures (for process heat/thermal efficiency), can run continuously (high capacity factor), is passively safe (can shut down and cool itself without external power or human intervention in accident scenarios), and doesn't require precision fuel fabrication. Downsides are that the radionuclides (including radioactive volatiles) are not contained in little pins and cans like in solid fueled reactors so you get radiation all over your pumps, your heat exchangers, and your reactor vessel. This is a solvable radiological containment issue (use good seals and double-walled vessels) but is a challenge (the MSRE in the 1960s lost almost half of its iodine; no one knows where it went!!)
U-Pu fuel can work in MSRs as well, getting those nice safety benefits, but it can't breed unless you have fast neutrons.
People on the internet may tell you that Thorium can't be used to make bombs and that it's extremely cheap, etc. These are not necessarily true. You can make bombs with a Th-U fuel cycle (just separate the Pa-233 before it decays), and nuclear system costs are unknown until you build and operate a few. There are reasons to hope it could be cheaper due to simplicity, but there are major additional complexities over traditional plants or other advanced reactors in the chemistry department that add a lot of uncertainty. Fluid fueled reactors are probably ~100x or more safer than traditional water-cooled reactors, on par with sodium-cooled fast reactors and other Gen-IV concepts with passive decay heat removal capabilities.
What has changed about that ?
Add to the insane risk of investing in anything 'nuclear' and you don't have a lot of available capital. That said, the Chinese who invest in research for other reasons seem to have been working on a number of MSRs which could conceivably advance the state of the art significantly.
Oddly enough, as an American, I am looking forward to the first thing that China builds that "we" American's cannot because we lack expertise and/or technology to do so.
Or too much regulation or politics to allow.
The incentives are obviously stronger in single-payer countries, but even in the US you could imagine an insurance company that competed on lower premiums conditional upon certain gene edits being applied to covered children.
On one hand, this sounds entirely economically reasonable (and even humanitarian).
On the other hand, I fear this would inevitably produce unintended consequences that would shape our society in distopian, sci-fi/horror-flavored ways.
I have no idea how it would actually shake out. Maybe I'm just being anti-intellectual here.
Or, as a German, too much regulation/politics to Get Shit Done.
Just look what happened to Transrapid (maglev rail). All tech and IP went off to China, and we're stuck in 1980-and-earlier carriages for anything not an ICE or regio trains.
Actually, the InterCity and EuroCity fleet was just entirely replaced.
This means the entire fleet – S, Region, InterCity, EuroCity, InterCityExpress – is now replaced, or being replaced, with modern stock.
InterCityExpress 4 (to replace major InterCity routes, and minor InterCityExpress routes): http://www.deutschebahn.com/de/bahnwelt/start_ice4/das_proje...
The United States and other nuclear weapons states never produced their weapons plutonium from light water reactors. Weapons grade plutonium has typically been produced from uranium in dedicated plutonium-production reactors moderated with heavy water or graphite. (The United States once had a single reactor that also produced commercial electricity along with weapons plutonium, https://en.wikipedia.org/wiki/N-Reactor, but it wasn't a light water reactor either.)
Since uranium fueled light water reactors weren't used to make plutonium for weapons in the first place, the thorium-myth claim that commercial power reactors stuck with uranium so as to make weapons material is ridiculous. The military's early sponsorship of light water reactors for naval propulsion did give uranium-fueled LWRs a significant historical path dependency advantage. I speculate that thorium advocates who continue to repeat the myth about how uranium LWRs became dominant do so because it makes the dominant technology's dominance sound more sinister, hence thorium sound more attractive by contrast.
Real reasons MSRs declined include :
* The existing major industrial and utility commitments to the LWR, HTGR, and LMFBR.
* The lack of incentive for industrial investment in supplying fuel cycle services, such as those required for solid fuel reactors.
* The overwhelming manufacturing and operating experience with solid fuel reactors in contrast with the very limited involvement with fluid fueled reactors.
* The less advanced state of MSBR technology and the lack of demonstrated solutions to the major technical problems associated with the MSBR concept.
What I thought that wasn't possible? Or is this just the speed of light in water, so the particles are still moving slower than the speed of light in a vacuum?
Good question! It's the latter - the shining is due to Cherenkov radiation , "electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium at a speed greater than the phase velocity of light in that medium."
Basically you can make reactors using it but it would probably work out more expensive than conventional ones.
"The inside of the Petten test reactor where the thorium salt is being tested is shining due to charged particles traveling faster than the speed of light in water."
As I understand it, nothing travels faster than the speed of light. The author is mistaken, right?
But the index of refraction of water is 1.33 . So the speed of light through water is much slower than through vacuum. And electrons can travel through water faster than light through water.
The effect is similar to a massive object traveling faster than the speed of sound through air.
Edit: I love that HN is so smart that a dogpile can form from all the people rushing in to explain Cherenkov radiation.
"Speed of light" seems simple, but is a bit more complicated than that.
“We will produce American coal to power American industry.”
Regardless, renewable is a less important concept than clean (how do you renew the sun which is a big nuclear reaction?).
Assuming energy demand growth of 5% per year, we have enough land-based actinates for less than a century of energy usage in fast breeder reactors (if you prefer 2% annual demand growth, it's enough for about 2 centuries).
Seawater uranium buys you more time, depending on how you extract it, but hundreds of years and the sun burning out are two very different timelines.
How has energy consumption behaved before around the time of paradigm shifts and plentiful "free" energy?
Solar panels do also need resources to produce...
It make take a long time for thorium reactors to come online but it is hard to believe anybody is going to fund the construction of a new large LWR anywhere outside China.
However, two problems remain:
1) where to get the raw material? African mines are not exactly known for adhering to human or environmental rights, also African mines, by nature of being in Africa, don't create American jobs. Same is valid for the other major sources of nuclear fuel, all of which aren't the USA.
2) where to dump all the nuclear waste? I mean, people have debated to put in the most long-living and nasty stuff into special reactors to get it split up to less harmful stuff, but to my knowledge this has never been realized - and NIMBYs are highly afraid of a rad-waste dump near their houses, across the world. Also, no one has shown how to build something that can last over ten thousands of years while still protecting the rad waste.
As for nuclear waste, the real reason why the problem appears intractable is that nuclear waste is not waste.
The LWR gets only 2% or so of the energy in uranium, the same fuel could be reprocessed and used in fast breeder reactors to release the other 98%. In fact, it is the presence of plutonium and other actinides in spent fuel that requires environmental isolation beyond 500 years or so. If we use those actinides as fuel, they do not need to be buried, and if we do that, the volume of waste is vastly reduced along with the half-life.
The fast breeder/reprocessing route has not been commercialized as of yet for a number of reasons. Probably the most discussed is that plutonium, neptunium and other actinides useful for nuclear weaponry could be nicked from the reprocessing plant.
The thorium MSR is an alternate path to a breeder, aka a "thermal breeder". In the case of the MSR, the reprocessing is done online or nearline to the reactor. It is also possible to do thermal breeding with thorium with a modified version of the light water reactor. Reprocessing that is a bitch though...
The most immediate problem facing the industry is an inability to say "it is going to take X years and Y dollars to build a reactor" and then finish it somewhere near on schedule and on budget. Being over 10% would be no scandal, but it is still looking more like 10x than 10%.
And I understand the Japanese had an experimental breeder reactor for a long time and never achieved actually producing any commercially viable electricity. They did get lots of plutonium, though, which may be turned into bombs any moment.
Plutonium from either a LWR or FBR fuel cycle is heavily contaminated with isotopes that will cause a bomb to predetonate or get really hot. Somebody with advanced technology (say Japan's government) could probably use electromagnetic separation to remove the unwanted isotopes, but you wouldn't expect ISIS to be able to do it.
The real thing terrorists would want to nick from a reprocessing plant is Neptunium 237; it has a large critical mass compared to plutonium, but it can be separated by chemical means and will not predetonate.
In the 1970s people wrote hang-wringing papers wondering if inventory control could be made good enough to detect diversion, a 2000s accident at Sellafield's THORP plant showed that it probably can't. They lost an Olymptic size swimming pool worth of fluid containing upwards of 50kg of Pu and around 1000kg of U and did not notice for months.
To be fair, it drained into a containment area and did not threaten anyone. They were able to clean it up. But obviously the inventory control was nonexistent.
THORP has been successful at producing plutonium oxide powder but the UK was unable to fabricate it into fuel elements and had to ship it to France.
I worry that that if Thorium reactors become very very common because they are thought to be very safe (e.g. behind your house common, as some have bragged), but they turn out to be dangerous...we will have a real problem.
We have decent electricity grids, if reactors become financially viable, first goal will be to power the grid.
I don't see any profit margin in decentralizing the grid.