It's not market share that determines if you violate antitrust legislation, it's what you do with it. You can have a 100% market share without having done anything wrong ( if not you could never bring a new product to the market, since it would initially have no competition ). What is illegal is to use your monopoly in one area to stifle competition in another.
I'm not saying Microsoft is innocent of doing so ( indeed they have been convicted of such practices in the past), just that people tend to misunderstand the legislation.
A different good example is that of SAS/Braathens airlines. They're a Scandinavian airline company that was convicted in European court for monopolistic behaviour with regards to their pricing of tickets. On line where they had competition they dropped their prices lower than the actual costs of flying, thus making it impossible for competitors to turn a profit. They financed it by increasing fares on flights where they had no competition. Since prices can be changed over night, it isn't feasible for competitors to respond by changing which airports they serve. It's a classic example of abusing your market position in order to make competition infeasible, without actually providing a better service.
The allegations vs google is that they are abusing their position in the search market in order to drive out competition in advertising.
Microsoft is probably guilty of similar violations in the OS market ( and have been convicted in the past ) but the actual market share has nothing to do with this. You could have a 50% market share and be guilty, or a 99% market share and be perfectly innocent. It's what you actually do with that market share that matters.
There are some niche cases where people respond better to one opioid than another. The same property that makes it dangerous ( it's long half-life ) is also desirable in some cases.
Of course, substituting it for oxycodone or morphine just because it is cheaper is simply stupid.
at least one of the assassinated scientists turned out to be a theoretical quantum mechanics lecturer with no skills or knowledge applicable to the type of nuclear science relating to weapons technology
It's way too late anyway. They have figured out how to do uranium enrichment, and most likely documented the process. Obtaining the material is the only part that is difficult. Beyond that the open literature will more or less tell you how to do it. Heck, if you gave me a significant quantity of highly enriched uranium, I could probably design a Hiroshima-style weapon from off-the shelf parts myself. For a uranium weapon all you really need to do is to take two slightly sub-critical pieces and fire them together at a high enough velocity. One of the assessments by the NRC even concluded that you'd have a 10% chance or so of successful assembly by simply dropping the pieces onto one another.
Plutonium is a bit more tricky, but by no means difficult compared to engineering feats Iran has already managed. Their rockets are orders of magnitude more difficult to make.
Also, you do know that most of his "outlandish quotes" are usually either purposefully mistranslated
You mean like the Iranian foreign ministry's official homepage translation, which mentioned erasing Israel of the map, until apologetic people in Europe started to pretend he was mistranslated, at which point they pulled their official translation and started to pretend it was Israeli propaganda?
Ahmadinejad is not even the worst when it comes to such crap. His predecessor referred to Israelis as "human only in appearance".
The idea with modular reactors is that if the components can be made small enough to be easily shipped from a central factory, instead of built on-site, then economy of volume will make up for the loss of economy of scale.
Also, the reason most proposed sodium designs is in the few hundred of MW range is mostly due to safety margins associated with sodium's boiling point and the wish for cooling through natural convection. Gen-4 designs that use supercritical water, lead or molten salt for coolant usually suggest higher outputs, in the order of magnitude of 800-1000MWth
Sodium cooled reactors consume the actinides as fuel, so you only get fission products in the waste. This alone reduced the necessary storage time for decay to uranium levels by several orders of magnitude, to about 300 years.
If you go further you can separate out strontium and caesium to let them decay separately. Since they are the major initial heat-load of the waste, and since they have modest half-lives, the net result is that storing strontium and caesium separately ends up using considerably less space. If all of these techniques were to be employed, Yucca would easily hold the entire nation's nuclear waste, and the waste would reach safe levels before the repository was full.
Other than all the fission products, including radioactive iodine, strontium and caesium (and others). Heck, just avoiding excessive tritium production involves isotope separation of lithium to enrich it in Li-7.
Essentially somebody has not told you teh full truth, or outright lied.
2. Uranium has an [Expensive] established fuel chain. You can only get fuel pellets from ONE supplier: the one who built the reactor. And no, they don't have sales.
Fuel costs are less than 10% of the cost of nuclear power. Construction and operation is the majority of it. Most estimates conclude that reprocessing ( even in the LFTR ) would be more expensive than uranium enrichment. You may save some money by not needing fuel manufacture , but in return you have a larger inventory of fissile material since it is not all in the core.
3. Advantage of thorium vs uranium: -No enrichment -No 10000 year radio-active waste
Nonsense. Thorium is not fissile, so it needs to be started on a large seed of fissile material. This could be either reprocessed plutonium or enriched uranium, just as with other reactors. Also, since plutonium cannot be effectively destroyed in a thermal spectrum, there will be a buildup of plutonium and curium, both of which have half-lives in the range of thousands of years, while still be very toxic.
-No high-pressure water cooling schemes that need power to work and backups up the wazoo.
Most modern designs, whether they use water or some other coolant, are built to not need power for emergency cooling. The ESBWR doesn't even use pumps during normal operation. This is not a feature of thorium, but a general property of decent engineering. Hot liquid flows up, cold comes down. This has been demonstrated successfully in virtually all types of coolant, including water, lead, sodium, salt and carbon dioxide and even nitrogen.
You may have a point about pressure, but there are other issues with salt systems. The need to keep the salt above it's several hundred centigrade melting point is one of them.
-Others mentioned in the video
There's loads of videos. Most of them are half-truths at best, and I'm not just talking about reactors. Seriously, you seem to never have come across a marketing campaign before.
The LFTR uses thorium dissolved in molten floride salt. It is proven tech, since the US government built one back in the late 60s and ran it for 5 years -- with 1.5 years at full power...
The devil is in the details.
While it is indeed possible to build an LFTR, that old bugger called economics tends to come and mess things up.
First of all you need a larger amount of fissile materials since the molten salt transports it out of the core. and around the entire primary loop. Secondly, as with sodium, you need to have a secondary loop to make things safe. Then there's the hydrolysis that can occur at low temperatures, which means you have to keep the salt molten. If the reactor has problems, that may involve drawing power from the grid. The reprocessing technologies kinda work, but are unproven at large scale, and nobody has an idea what the cost will be for a large reactor. They also imply building reprocessing tech for every single plant, which increases capital costs.
Then there is the startup material. Natural uranium is not good enough, so you either need to breed U-233 in a different reactor ( proliferation concern ) , use highly enriched U-235 ( proliferation concern, expensive ) , or startup on plutonium. Now plutonium in a thermal spectrum leads to accumulation of Curium, which is a troublesome waste product that cannot be efficiently destroyed in a thermal reactor.
Add in that while Thorium and Uranium dissolves easily in fluoride salts, plutonium and the other actinides do not. In fact, even at high temperatures with a completely pure salt, the solubility of Pu fluorides is just a few percent. The molten salt reactor experiments got around these issues by using a very exotic salt. Beryllium and Lithium fluorides, with the lithium enriched in Li-7. Now, beryllium is highly toxic, expensive and difficult to work with. It's such a pain that the US and UK considered developing new nuclear warheads that did not use it, even though it is the best lightweight neutron reflector there is. Enriched lithium-7 is a different problem in itself, and even if 99% pure, you will get quite a bit of tritium when it is exposed to neutrons. Perhaps not more than in a CANDU reactor, but all tritium control systems ever designed are made for water coolant.
Then is the issue of in-core materials. The molten salt reactor developed by the US dealt with damage to in-core materials by replacing the graphite core materials frequently. Not only is this expensive, but it's not very fun to handle radioactively contaminated graphite. It is hard to reprocess since it forms organic compounds and is difficult to dissolve in nitric acid. Pyro-processing by electro-refining and similar is also poorly suited for graphite. This is one of the reasons why the pebble bed reactors are usually seen as "once through". Nobody has come up with a practical way to deal with the graphite. Since the material will be in direct contact with the fuel salt, it will likely adsorb quite a bit of contaminants.
Plateout on heat exchangers is another issue. The noble metals have poor solubility in fluoride salts, so unless a very potent ( i.e expensive ) reprocessing system is able to get rid of them quickly, they will plate out on the cold parts of the reactor, which is usually the heat exchangers. A suggested solution is to use graphite-based heat exchangers, which has its own spectrum of development issues and research needs.
I'm not saying molten salt reactors can never become a good idea. I'm just saying that in comparison to the number of issues that need to be resolved to make them practical for a power plant, they are extremely hyped.
Some pages have ads that are non-intrusive in on windows, but break horribly on a Linux machine. This most commonly occurs with ads that use flash, so you can avoid the worst lot by blocking flash except for when you need it.
Also, while the browser should be able to handle it, it has happened that some poorly coded site managed to lock-up my browser or crash it. That should not happen to a well written browser of course, but blocking ads all but eliminates it.
The bad part about this is that "if you don't like the site don't visit it", won't help, because you only realise it will break things after you visit. It also happens on occasion that this kind of problem happens to sites you kinda need to use, such as when you try to print a form to fill in your taxes.
>Bullshit... I have never had a Linux install take longer than a Windows install, even with "problems." Generally, a Linux install takes less than an hour. Two hours if there is an odd graphics or WiFi bug. Windows takes 3 minimum, and often more if you need odd drivers.
That's probably because you install it on things that you know it will work on. It gets a lot more "fun" when you try to put it onto some random friend's windows box, and realize half the hardware is cheap, doesn't have stable linux drivers, and that the programs they use don't run well on Linux.
It has gotten better lately, but you still run into crappy hardware and peripherals that will at best work at 70% of their potential after a lot of poking. It's not the fault of Linux of course, but it is still something you end up having to deal with.
Malaria however is another one desparately in need of research. Kills more than aids and yet gets a fraction of the research dollars.
Tragic fact: Malaria doesn't have any non-human carriers, and it doesn't last long in the mosquitoes that transmit it. Thus if we ensured everybody that needed it could get treatment for malaria, the disease would likely die out.
You know, as somebody who has always been slim enough to frequently get comments along the lines of "you need to eat more" (and it really isn't fun to get told that when I'm perfectly healthy ), I get a bit ticked off with sentiments like this. Yes, it's horrible that the fashion industry makes curvy women feel bad, but the reverse is not a good idea either. I think it was in the UK authorities banned pictures of a slim model as "socially irresponsible" recently, because she was too thin. Thing is, she looked very similar to myself, and my doctor thinks I'm fine ( as does the BMI scale , even though it is obviously not all that reliable ).
There's a wide range of healthy body weights, and calling people on the lower end of the scale names because you're upset with how those who are chubby are treated will only make things worse. Replacing one set of really harmful sentiments about body weight with another will result in people feeling pushed to fit some very narrow line between "omg, you shouldn't be so slim, you must have some eating disorder" and "too 'fat' to be a model".
Not true. Modern gas fuelled plants tend to use use a combined cycle gas turbine.
First the gas is burned and allowed to drive a gas turbine, after which the heat is collected by a water turbine. Finally any residual heat can be captured and utilized in combined heat and power schemes.
There's also plants that use supercritical water. It never boils because it operates above its critical point. This allows for water to be used on a brayton cycle ( basically a closed cycle gas turbine ), which greatly increases the thermodynamic efficiency as compared to the rankine cycle.
Unless of course your statement was "trololol, the power conversion system involves thermodynamic phase transitions in water, it's practically the same as a steam engine and think about how primitive those are!" in which case you're just being deliberately stupid.
Here's a clue - liquid sodium is used for technical and not safety reasons.
That's half true. There's a number of properties that make sodium very attractive as a coolant:
-It is much less corrosive to many steel alloys than is water. Some alloys don't corrode at all. -It allows for a high power density -High thermal conductivity -The reactor need not be pressurised -Low neutron capture cross section -Modest melting point -It only forms short lived radio-isotopes when irradiated -High operating temperature ( as compared to water )
From a safety perspective a properly designed sodium cooled reactor is very unlikely to suffer a LOCA due to the low pressure, natural circulation allows for sufficient heat transport even during a total loss of power, the higher thermal conductivity enables fast thermal feedbacks and the higher thermal efficiency ( due to higher temperatures ) means somewhat less decay heat has to be transported away.
Two things, first it only consumes a small portion of nuclear waste and produces a larger volume of a different type of waste - which I'm sure you already know.
It can completely fission the actinides you feed it, and the waste it produces decay to safe levels within 300 years, as opposed to 100.000 for the original wastes. Plutonium that has been recycled through it would also be almost useless for nuclear weapons since the isotopic composition after 1 or two passes is even worse than reactor grade plutonium. The reason it only consumes a small portion of nuclear waste is because it needs almost 100 times less fuel than a conventional reactor ( thanks to a positive breeding gain ) , which conversely means that if you consider all the waste we have, there's enough fuel for a thousand years or so.
Now there are alternative breeder designs to sodium coolant. Lead, molten salt, helium or supercritical water could all work. They all have their respective advantages and disadvantages.
Fast reactors are somewhat notorious for being trickier to control than (well-designed) thermal ones. It's very difficult to avoid a positive void coefficient, and fairly small changes in the fuel geometry can lead to large changes in reactivity. There was a meltdown in an early FBR caused by thermal expansion causing the fuel to bow inwards, increasing the reactivity. Phenix in France also had unexplained loss of reactivity incidents.
The void coefficient is almost unavoidably positive since these reactors don't rely on moderators and the coolants thus acts mostly as a neutron absorber/reflector. However, if you build the reactor the right way, then thermal expansion of the fuel, Doppler broadening, and increased neutron leakage due to expansion of the coolant can make the overall thermal coefficient negative.
It is in principle posible to make the void coefficient negative, but it tends to involve a heterogeneous core with many different enrichment zones, and it is harder to simulate.
Our nuclear program was originally intended to use heavy water reactors to produce both power and plutonium for weapons. They were to be fuelled by natural uranium mined in Sweden. The campaign got so far as to produce significant quantities of super weapons grade ( >98% Pu-239 ) plutonium. When Sweden abandoned the nuclear programme in favour of becoming part of the non-proliferation treaty, the heavy water program turned out to be much more expensive than the light water solutions developed by the US. Most of Swedish reactor designs are thus based on ( but different from ) the American BWRs. The main differences are a better containment building, the use of filter systems which can relieve pressure in the drywell without releasing iodine and radioactive aerosols, as well as a number of various upgrades to improve safety and performance.
As compared the the US nuclear industry the main thing Sweden did better was to construct a well protected interim storage facility (work on a final repository is still progressing at a slow but steady rate ). Because of this our spent fuel rests under many meters of bedrock in ponds that have many redundant cooling systems and large margins. Contrast this to the US situation where many of the cooling ponds now store much greater quantities of waste than they were ever designed to hold.
I believe the union of concerned scientists have long held that the US ought to implement interim storage in order to relieve the spent fuel ponds without having to rush a final repository. They seem to suggest Dry-cask storage as the preferred option.
The travelling wave reactor concept appears to be basically a sodium cooled reactor that has a lot of extra U-238 , allowing it to go very long without refuelling as the enriched portion of the core "travels" along the U-238 ( this image explains the concept: http://evworld.com/press/IV_twr_concept.jpg ).
I have to say I am sceptical. The main economic issue with sodium cooled fast breeders is that they are very capital intensive due to the challenges of handling flammable sodium. Thus trading even more capital investment ( in the form of a larger core ) for less frequent refuelling seems like a bad idea. Furthermore, any design that is to see widespread deployment should make use of economics of scale. Fuel fabrication, reprocessing and so on can be centralised, with a few facilities potentially serving many reactors, or even multiple nations. It thus makes little sense to move capital costs towards the power plant and reactor, away from facilities that can be centralised. This is why I doubt all the talk about "Integral" facilities or on-line reprocessing ( as suggested for molten salt reactors ).
It's not very hard to build a breeder with a 2-3 year core lifetime anyway, and you probably don't want to run it much longer than that without shutting it down for servicing, repairs, inspection and so on.
Don't get me wrong. It's a cool idea technologically. I just don't think it will be economically competitive with other Gen-IV designs. The focus for breeders today should be on reducing capital up-front investment, improved safety and reliability. No utility is going to invest billions up-front in an experimental design that is unlikely to be economically competitive with other alternatives.
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.
Unless one argues that the Chinese people are less valuable than the US citizens (you can't even tell them from one another!), I don't see, how one can critisise China without being a hypocrite.
The problem is that China doesn't even care about its own citizens, and isn't really using the industrial output it gets from the fossil fuels to improve their situation much. Shanghai is now so polluted the smog can make you not see the sun. They got mercury all over the place, and they are also one of the countries that are likely to see massive humanitarian problems as a result of climate change.
Furthermore, while China is presently lower per capita in emissions than the US , they are climbing quickly, and they seem to be doing little more than token measures trying to curtail the emissions. Basically, if we actually found it likely that China would stabilise its emissions and strive to improve its environmental record for the well-being of its people. Well, that would be one thing. Sadly the government there seem to mostly be using the people as an excuse to pollute.
I just really hope somebody will invent a type of nuke plant or wind turbine or something that actually is much cheaper than coal. Because short of that happening China will continue its path towards disaster.
The problem is lack of effective regulations and oversight. Making something government owned doesn't stop that. You need the people who inspect the stuff to be independent from those who profit from it. If the government wasn't full of industry lobbyists then private run - government inspected , would probably do the job pretty well.
Unless you were as thick as two short planks(and many sadly are), you would never ever ever ever run a nuclear plant on windows. Or even linux. Or even siemens hardware in general. You would use a robust PLC from someone like Omron and some dedicated HMIs to backup your SCADA, which will sadly run windows. The PLC program should be properly interlocked and fail safe. The plant runs on the PLC not the SCADA.
There are many different systems at a huge power plant. Some of them are more critical than others.
Hence for something like the control-rods or other safety shut-down mechanisms, yea you probably want them to work even without computers. Heck, many modern plants suspend the control rods from electromagnets, meaning they will drop into the core if the power is cut.
On the other hand, the computers you use to e-mail the kitchen staff, to tell them you're out of plastic cups in the cafeteria, can probably be run on any old desktop OS.
What I find astonishing about Fukushima is learning that we've decided to keep nuclear waste in a manner that is not failsafe. That we need to actively cool.
That's only true because the Japanese ( like the Americans ) have failed to build an interim storage facility, and hence they ended up storing way more spent fuel on-site than was ever intended. The cooling ponds were never meant to keep a reactor's lifetime of spent fuel on-site.
In contrast, in most European countries the fuel is shipped away as soon as it is safe to do so. In Sweden we store it in a special facility with redundant cooling options, beneath tens of meters of bedrock. Should the facility lose all it's power, it would take a month or so before you'd have to refill it with water, and unlike the Fukushima plant, using salt-water from the nearby baltic sea would not ruin the facility.
TL:DR: It can easily be done safely, but NIMBYism has prevented some countries from building the facilities that would do the job.
Salt mines is a bad idea mostly because it is hard to monitor and difficult to recover should there turn out to be problems.
In the United states Yucca Mountain would probably be best, assuming the waste is stored in such a way that it can be recovered, should you want to do something else with it.
There's been a lot of criticism about Yucca in terms of it's safety over geological time periods, but if the waste is stored in a recoverable fashion, then it is still the safest place you can put it at the moment. It is certainly miles better than the on-site storage pools anyway.
Slashdot Mirror
It's not market share that determines if you violate antitrust legislation, it's what you do with it.
You can have a 100% market share without having done anything wrong ( if not you could never
bring a new product to the market, since it would initially have no competition ). What is illegal
is to use your monopoly in one area to stifle competition in another.
I'm not saying Microsoft is innocent of doing so ( indeed they have been convicted of such practices
in the past), just that people tend to misunderstand the legislation.
A different good example is that of SAS/Braathens airlines. They're a Scandinavian airline company
that was convicted in European court for monopolistic behaviour with regards to their pricing of tickets.
On line where they had competition they dropped their prices lower than the actual costs of flying, thus
making it impossible for competitors to turn a profit. They financed it by increasing fares on flights where
they had no competition. Since prices can be changed over night, it isn't feasible for competitors to respond
by changing which airports they serve. It's a classic example of abusing your market position in order to
make competition infeasible, without actually providing a better service.
The allegations vs google is that they are abusing their position in the search market in order to drive out
competition in advertising.
Microsoft is probably guilty of similar violations in the OS market ( and have been convicted in the past ) but
the actual market share has nothing to do with this. You could have a 50% market share and be guilty, or a 99%
market share and be perfectly innocent. It's what you actually do with that market share that matters.
There are some niche cases where people respond better to one opioid than another. The same property that makes it dangerous ( it's long half-life ) is also desirable in some cases.
Of course, substituting it for oxycodone or morphine just because it is cheaper is simply stupid.
It's way too late anyway. They have figured out how to do uranium enrichment, and most likely documented the process. Obtaining the material is the only part that is difficult. Beyond that the open literature will more or less tell you how to do it. Heck, if you gave me a significant quantity of highly enriched uranium, I could probably design a Hiroshima-style weapon from off-the shelf parts myself. For a uranium weapon all you really need to do is to take two slightly sub-critical pieces and fire them together at a high enough velocity. One of the assessments by the NRC even concluded that you'd have a 10% chance or so of successful assembly by simply dropping the pieces onto one another.
Plutonium is a bit more tricky, but by no means difficult compared to engineering feats Iran has already managed. Their rockets are orders of magnitude more difficult to make.
You mean like the Iranian foreign ministry's official homepage translation, which mentioned erasing Israel of the map, until apologetic people in Europe started to pretend he was mistranslated, at which point they pulled their official translation and started to pretend it was Israeli propaganda?
Ahmadinejad is not even the worst when it comes to such crap. His predecessor referred to Israelis as "human only in appearance".
In this particular case you got it wrong.
The idea with modular reactors is that if the components can be made small enough to be easily shipped from a central factory, instead of built on-site, then economy of volume will make up for the loss of economy of scale.
Also, the reason most proposed sodium designs is in the few hundred of MW range is mostly due to safety margins associated with sodium's boiling point and the wish for cooling through natural convection. Gen-4 designs that use supercritical water, lead or molten salt for coolant usually suggest higher outputs, in the order of magnitude of 800-1000MWth
Actually it does.
Sodium cooled reactors consume the actinides as fuel, so you only get fission products in the waste. This alone reduced the necessary storage time for decay to uranium levels by several orders of magnitude, to about 300 years.
If you go further you can separate out strontium and caesium to let them decay separately. Since they are the major initial heat-load of the waste, and since they have modest half-lives, the net result is that storing strontium and caesium separately ends up using considerably less space. If all of these techniques were to be employed, Yucca would easily hold the entire nation's nuclear waste, and the waste would reach safe levels before the repository was full.
Other than all the fission products, including radioactive iodine, strontium and caesium (and others). Heck, just avoiding excessive tritium production involves isotope separation of lithium to enrich it in Li-7.
Essentially somebody has not told you teh full truth, or outright lied.
Fuel costs are less than 10% of the cost of nuclear power. Construction and operation is the majority of it. Most estimates conclude that reprocessing ( even in the LFTR ) would be more expensive than uranium enrichment. You may save some money by not needing fuel manufacture , but in return you have a larger inventory of fissile material since it is not all in the core.
Nonsense. Thorium is not fissile, so it needs to be started on a large seed of fissile material. This could be either reprocessed plutonium or enriched uranium, just as with other reactors. Also, since plutonium cannot be effectively destroyed in a thermal spectrum, there will be a buildup of plutonium and curium, both of which have half-lives in the range of thousands of years, while still be very toxic.
Most modern designs, whether they use water or some other coolant, are built to not need power for emergency cooling.
The ESBWR doesn't even use pumps during normal operation. This is not a feature of thorium, but a general property of
decent engineering. Hot liquid flows up, cold comes down. This has been demonstrated successfully in virtually all types
of coolant, including water, lead, sodium, salt and carbon dioxide and even nitrogen.
You may have a point about pressure, but there are other issues with salt systems. The need to keep the salt above it's several
hundred centigrade melting point is one of them.
There's loads of videos. Most of them are half-truths at best, and I'm not just talking about reactors. Seriously, you seem to never have come across a marketing campaign before.
The devil is in the details.
While it is indeed possible to build an LFTR, that old bugger called economics tends to come and mess things up.
First of all you need a larger amount of fissile materials since the molten salt transports it out of the core. and around the entire primary loop. Secondly, as with sodium, you need to have a secondary loop to make things safe. Then there's the hydrolysis that can occur at low temperatures, which means you have to keep the salt molten. If the reactor has problems, that may involve drawing power from the grid. The reprocessing technologies kinda work, but are unproven at large scale, and nobody has an idea what the cost will be for a large reactor. They also imply building reprocessing tech for every single plant, which increases capital costs.
Then there is the startup material. Natural uranium is not good enough, so you either need to breed U-233 in a different reactor ( proliferation concern ) , use highly enriched U-235 ( proliferation concern, expensive ) , or startup on plutonium. Now plutonium in a thermal spectrum leads to accumulation of Curium, which is a troublesome waste product that cannot be efficiently destroyed in a thermal reactor.
Add in that while Thorium and Uranium dissolves easily in fluoride salts, plutonium and the other actinides do not. In fact, even at high temperatures with a completely pure salt, the solubility of Pu fluorides is just a few percent. The molten salt reactor experiments got around these issues by using a very exotic salt. Beryllium and Lithium fluorides, with the lithium enriched in Li-7. Now, beryllium is highly toxic, expensive and difficult to work with. It's such a pain that the US and UK considered developing new nuclear warheads that did not use it, even though it is the best lightweight neutron reflector there is. Enriched lithium-7 is a different problem in itself, and even if 99% pure, you will get quite a bit of tritium when it is exposed to neutrons. Perhaps not more than in a CANDU reactor, but all tritium control systems ever designed are made for water coolant.
Then is the issue of in-core materials. The molten salt reactor developed by the US dealt with damage to in-core materials by replacing the graphite core materials frequently. Not only is this expensive, but it's not very fun to handle radioactively contaminated graphite. It is hard to reprocess since it forms organic compounds and is difficult to dissolve in nitric acid. Pyro-processing by electro-refining and similar is also poorly suited for graphite. This is one of the reasons why the pebble bed reactors are usually seen as "once through". Nobody has come up with a practical way to deal with the graphite. Since the material will be in direct contact with the fuel salt, it will likely adsorb quite a bit of contaminants.
Plateout on heat exchangers is another issue. The noble metals have poor solubility in fluoride salts, so unless a very potent ( i.e expensive ) reprocessing system is able to get rid of them quickly, they will plate out on the cold parts of the reactor, which is usually the heat exchangers. A suggested solution is to use graphite-based heat exchangers, which has its own spectrum of development issues and research needs.
I'm not saying molten salt reactors can never become a good idea. I'm just saying that in comparison to the number of issues that need to be resolved to make them practical for a power plant, they are extremely hyped.
It's even worse than that.
Some pages have ads that are non-intrusive in on windows, but break horribly on a Linux machine.
This most commonly occurs with ads that use flash, so you can avoid the worst lot by blocking flash
except for when you need it.
Also, while the browser should be able to handle it, it has happened that some poorly coded site managed
to lock-up my browser or crash it. That should not happen to a well written browser of course, but blocking
ads all but eliminates it.
The bad part about this is that "if you don't like the site don't visit it", won't help, because you only realise it
will break things after you visit. It also happens on occasion that this kind of problem happens to sites you
kinda need to use, such as when you try to print a form to fill in your taxes.
>Bullshit... I have never had a Linux install take longer than a Windows install, even with "problems." Generally, a Linux install takes less than an hour. Two hours if there is an odd graphics or WiFi bug. Windows takes 3 minimum, and often more if you need odd drivers.
That's probably because you install it on things that you know it will work on. It gets a lot more "fun" when you try to put it onto some random friend's windows box, and realize half the hardware is cheap, doesn't have stable linux drivers, and that the programs they use don't run well on Linux.
It has gotten better lately, but you still run into crappy hardware and peripherals that will at best work at 70% of their potential after a lot of poking. It's not the fault of Linux of course, but it is still something you end up having to deal with.
I knew there was a language issue. Had they only realise that in manager speak "it still have some issues" means "ship it" ...
Tragic fact:
Malaria doesn't have any non-human carriers, and it doesn't last long in the mosquitoes that transmit it. Thus if we ensured everybody that needed it could get treatment for malaria, the disease would likely die out.
The same is true for tuberculosis.
You know, as somebody who has always been slim enough to frequently get comments along the lines of "you need to eat more" (and it really isn't fun to get told that when I'm perfectly healthy ), I get a bit ticked off with sentiments like this. Yes, it's horrible that the fashion industry makes curvy women feel bad, but the reverse is not a good idea either. I think it was in the UK authorities banned pictures of a slim model as "socially irresponsible" recently, because she was too thin. Thing is, she looked very similar to myself, and my doctor thinks I'm fine ( as does the BMI scale , even though it is obviously not all that reliable ).
There's a wide range of healthy body weights, and calling people on the lower end of the scale names because you're upset with how those who are chubby are treated will only make things worse. Replacing one set of really harmful sentiments about body weight with another will result in people feeling pushed to fit some very narrow line between "omg, you shouldn't be so slim, you must have some eating disorder" and "too 'fat' to be a model".
Oh bollocks. Ericsson would be just fine without Syria, and Finland didn't complain because of Nokia.
Our government just needs to grow a spine.
Not true. Modern gas fuelled plants tend to use use a combined cycle gas turbine.
First the gas is burned and allowed to drive a gas turbine, after which the heat is collected by a water turbine. Finally any residual heat can be captured and utilized in combined heat and power schemes.
There's also plants that use supercritical water. It never boils because it operates above its critical point. This allows for water to be used on a brayton cycle ( basically a closed cycle gas turbine ), which greatly increases the thermodynamic efficiency as compared to the rankine cycle.
Unless of course your statement was "trololol, the power conversion system involves thermodynamic phase transitions in water, it's practically the same as a steam engine and think about how primitive those are!" in which case you're just being deliberately stupid.
That's half true. There's a number of properties that make sodium very attractive as a coolant:
-It is much less corrosive to many steel alloys than is water. Some alloys don't corrode at all.
-It allows for a high power density
-High thermal conductivity
-The reactor need not be pressurised
-Low neutron capture cross section
-Modest melting point
-It only forms short lived radio-isotopes when irradiated
-High operating temperature ( as compared to water )
From a safety perspective a properly designed sodium cooled reactor is very unlikely to suffer a LOCA due to the low pressure, natural circulation allows for sufficient heat transport even during a total loss of power, the higher thermal conductivity enables fast thermal feedbacks and the higher thermal efficiency ( due to higher temperatures ) means somewhat less decay heat has to be transported away.
It can completely fission the actinides you feed it, and the waste it produces decay to safe levels within 300 years, as opposed to 100.000 for the original wastes. Plutonium that has been recycled through it would also be almost useless for nuclear weapons since the isotopic composition after 1 or two passes is even worse than reactor grade plutonium. The reason it only consumes a small portion of nuclear waste is because it needs almost 100 times less fuel than a conventional reactor ( thanks to a positive breeding gain ) , which conversely means that if you consider all the waste we have, there's enough fuel for a thousand years or so.
Now there are alternative breeder designs to sodium coolant. Lead, molten salt, helium or supercritical water could all work. They all have their respective advantages and disadvantages.
The void coefficient is almost unavoidably positive since these reactors don't rely on moderators and the coolants thus acts mostly as a neutron absorber/reflector. However, if you build the reactor the right way, then thermal expansion of the fuel, Doppler broadening, and increased neutron leakage due to expansion of the coolant can make the overall thermal coefficient negative.
It is in principle posible to make the void coefficient negative, but it tends to involve a heterogeneous core with many different enrichment zones, and it is harder to simulate.
Our nuclear program was originally intended to use heavy water reactors to produce both power and plutonium for weapons. They were to be fuelled by natural uranium mined in Sweden. The campaign got so far as to produce significant quantities of super weapons grade ( >98% Pu-239 ) plutonium. When Sweden abandoned the nuclear programme in favour of becoming part of the non-proliferation treaty, the heavy water program turned out to be much more expensive than the light water solutions developed by the US. Most of Swedish reactor designs are thus based on ( but different from ) the American BWRs. The main differences are a better containment building, the use of filter systems which can relieve pressure in the drywell without releasing iodine and radioactive aerosols, as well as a number of various upgrades to improve safety and performance.
As compared the the US nuclear industry the main thing Sweden did better was to construct a well protected interim storage facility (work on a final repository is still progressing at a slow but steady rate ). Because of this our spent fuel rests under many meters of bedrock in ponds that have many redundant cooling systems and large margins. Contrast this to the US situation where many of the cooling ponds now store much greater quantities of waste than they were ever designed to hold.
I believe the union of concerned scientists have long held that the US ought to implement interim storage in order to relieve the spent fuel ponds without having to rush a final repository. They seem to suggest Dry-cask storage as the preferred option.
The travelling wave reactor concept appears to be basically a sodium cooled reactor that has a lot of extra U-238 , allowing it to go very long without refuelling as the enriched portion of the core "travels" along the U-238 ( this image explains the concept: http://evworld.com/press/IV_twr_concept.jpg ).
I have to say I am sceptical. The main economic issue with sodium cooled fast breeders is that they are very capital intensive due to the challenges of handling flammable sodium. Thus trading even more capital investment ( in the form of a larger core ) for less frequent refuelling seems like a bad idea. Furthermore, any design that is to see widespread deployment should make use of economics of scale. Fuel fabrication, reprocessing and so on can be centralised, with a few facilities potentially serving many reactors, or even multiple nations. It thus makes little sense to move capital costs towards the power plant and reactor, away from facilities that can be centralised. This is why I doubt all the talk about "Integral" facilities or on-line reprocessing ( as suggested for molten salt reactors ).
It's not very hard to build a breeder with a 2-3 year core lifetime anyway, and you probably don't want to run it much longer than that without shutting it down for servicing, repairs, inspection and so on.
Don't get me wrong. It's a cool idea technologically. I just don't think it will be economically competitive with other Gen-IV designs. The focus for breeders today should be on reducing capital up-front investment, improved safety and reliability. No utility is going to invest billions up-front in an experimental design that is unlikely to be economically competitive with other alternatives.
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.
The problem is that China doesn't even care about its own citizens, and isn't really using the industrial output it gets from the fossil fuels to improve their situation much. Shanghai is now so polluted the smog can make you not see the sun. They got mercury all over the place, and they are also one of the countries that are likely to see massive humanitarian problems as a result of climate change.
Furthermore, while China is presently lower per capita in emissions than the US , they are climbing quickly, and they seem to be doing little more than token measures trying to curtail the emissions. Basically, if we actually found it likely that China would stabilise its emissions and strive to improve its environmental record for the well-being of its people. Well, that would be one thing. Sadly the government there seem to mostly be using the people as an excuse to pollute.
I just really hope somebody will invent a type of nuke plant or wind turbine or something that actually is much cheaper than coal. Because short of that happening China will continue its path towards disaster.
You mean like Chernobyl?
The problem is lack of effective regulations and oversight. Making something government owned doesn't stop that. You need the people who inspect the stuff to be independent from those who profit from it. If the government wasn't full of industry lobbyists then private run - government inspected , would probably do the job pretty well.
There are many different systems at a huge power plant. Some of them are more critical than others.
Hence for something like the control-rods or other safety shut-down mechanisms, yea you probably want them to work even without computers. Heck, many modern plants suspend the control rods from electromagnets, meaning they will drop into the core if the power is cut.
On the other hand, the computers you use to e-mail the kitchen staff, to tell them you're out of plastic cups in the cafeteria, can probably be run on any old desktop OS.
That's only true because the Japanese ( like the Americans ) have failed to build an interim storage facility, and hence they ended up storing way more spent fuel on-site than was ever intended. The cooling ponds were never meant to keep a reactor's lifetime of spent fuel on-site.
In contrast, in most European countries the fuel is shipped away as soon as it is safe to do so. In Sweden we store it in a special facility with redundant cooling options, beneath tens of meters of bedrock. Should the facility lose all it's power, it would take a month or so before you'd have to refill it with water, and unlike the Fukushima plant, using salt-water from the nearby baltic sea would not ruin the facility.
TL:DR: It can easily be done safely, but NIMBYism has prevented some countries from building the facilities that would do the job.
Salt mines is a bad idea mostly because it is hard to monitor and difficult to recover should there turn out to be problems.
In the United states Yucca Mountain would probably be best, assuming the waste is stored in such a way that it can be recovered, should you want to do something else with it.
There's been a lot of criticism about Yucca in terms of it's safety over geological time periods, but if the waste is stored in a recoverable fashion, then it is still the safest place you can put it at the moment. It is certainly miles better than the on-site storage pools anyway.