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Rand alPaul posted:This pro-Thorium website of dubious credibility says a 1 GW Thorium plant would cost $250m to construct. There's a few slightly more robust calculations out there. Kirk pulled some numbers together on his blog for small modular systems: http://energyfromthorium.com/2010/07/11/ending-energy-poverty/ Here's what he had to say about its fuel economy: http://energyfromthorium.com/cubic-meter/ While Charles Barton estimates the LFTR could cost as little as 1.25 billion per 1 GWe overnight costs: http://energyfromthorium.com/2009/05/17/scaling-the-lftr-large-scale-production-and-cost/ There are other studies out there, including some very early studies by the ORNL team as well as a few recent ones by economists. To be frank, I'd be dubious about anything below 2 billion per GWe for any sort of nuclear system. The lion's share of costs to building a new plant today comes almost exclusively from regulatory hurdles and delays: http://www.phyast.pitt.edu/~blc/book/chapter9.html quote:The increase in total construction time, indicated in Fig. 2, from 7 years in 1971 to 12 years in 1980 roughly doubled the final cost of plants. In addition, the EEDB (cost of building a nuclear power plant at the current price of labor and materials), corrected for inflation, approximately doubled during that time period. Thus, regulatory ratcheting, quite aside from the effects of inflation, quadrupled the cost of a nuclear power plant.
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Sep 4, 2012 13:10
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coffeetable posted:FUSION Most don't seem to comprehend what fusion is and what it will do once we figure out how to make it work. Fusion is dreamed about by most because of its incredible energy specificity (6 times that of fission), which is what would make it cheap and clean. Theoretically you would need "far less" of it to produce the same energy you would using anything else. But that's not actually the kicker for fusion. What it's really good at is producing excess neutrons. Some fusion pathways can produce up to 2 extra neutrons per reaction, which can lead to breeding ratios above 2.5. To give you a bit of contrast, plutonium breeding only ever got up to a ratio of 1.2. http://en.wikipedia.org/wiki/Fusion_reaction http://en.wikipedia.org/wiki/Plutonium_economy This neutronicity is quite litterally the best and worst thing about nuclear fusion, and nuclear in general. On the bright side, you have the ability to create a massive surplus of nuclear fuel from extremely common fertile isotopes: Lithium-7 (over 90% of natural lithium) can be used to make tritium with no net neutron loss, two tritium can be fused to produce 2 neutrons and a lot of energy, said 2 neutrons can go on to transmute 2 thorium-232 (common as lead) or uranium-238 (99.3% of all natural uranium) into uranium-233 and plutonium-239, respectively. And those 2 fissile fuels also have positive neutronicities when used in their own breeder reactors. The only cost to all this would be reserved in actually building the reactors to use the fuels. Transmuting heavier isotopes is itself beneficial because it leads to medical, industrial, and power-relevant isotopes that you simply can't acquire in any other way. On the downside, that fissile material you made can also be used in bombs. You can incorporate safeties against this in your system (dirtying up your isotopes by irradiating them for too long for example), but any state with decent knowledge and a retrofitted fusion reactor could make weapons-grade stuff fairly easily. Ironically, the most successful fusion reactors have also been the ones that use fission-fusion thermonuclear bombs to produce heat/neutrons in controlled environments, like PACER. coffeetable posted:THORIUM There's a lot of wrong here. Thorium doesn't fission, and it's completely different from uranium in terms of what's required to use it effectively. It is most effective in liquid-fueled systems, in which there are no fabrication costs and no handling concerns. Waste also becomes a limited issue, since breeders can transmute and destroy all transuranics and most fission products with enough excess neutron radiation. As for dirty bombs, that's largely a media scare thing. Most rogue states have ready-access to chemical warfare agents which are far more destructive than fallout in every sense. In thermonuclear weapons, we are most concerned with Uranium-233 (the actual fuel of the thorium cycle), which is itself not very good in bombs because it doesn't fission very well under fast-neutron conditions (Operation Teapot tried it out with limited success). However it lacks any serious "neutron poisons" which typically cripple isotopes like Plutonium and impure U-235 in bombs, which makes it really easy to use and set off. The problem is that U-233 comes with a bitch of an isotope, U-232. This guy is part of an off-branch of the Neptunium series decay chain which ends off with Thallium-208 decaying to Lead and releasing a gently caress-off huge amount of gamma radiation (2.6 MeV, which is like half of what you get from a typical fission reaction) easily enough to maim anyone in the vicinity and fry electronics. The radiation signature is powerful enough to be detected from orbital space. http://en.wikipedia.org/wiki/Thorium_cycle#Uranium-232_contamination There are ways to produce U-233 without any U-232, but it's very difficult and requires special (obviously illegal) systems or practices in all cases. You would definitely not be able to do it economically with a solid-fueled reactor, since you need very fast and frequent reprocessing of any bred intermittent fuel. In liquid-fueled systems, depending on what configuration you go with, you'll either not be able to legally use the reprocessing method needed for potential production of pure U-233, or you will simply not be able to keep the reactor online if you decided to divert material to make a bomb. Office Thug fucked around with this message at 22:00 on Sep 4, 2012 |
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Sep 4, 2012 21:58
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Hobo Erotica posted:Cheers, I'll chuck this in the OP, unless office Thug has some objections or wants to clean it up. I'll be honest, I do love all science, but my eyes glaze over with chemistry, particularly nuclear physics. So I'm not as good with that as I should be. The bit on fusion is great. You might want to add that five thousand tonnes of lithium would be enough to power the world for a year via fusion, with everything from synthetic fuel production to electricity. Current world output of lithium is 34000 tonnes per year, and the total easily accessible reserves are around 13 million tonnes. You can also mix lithium usage with deuterium usage at the cost of the reactions only yielding 1 extra neutron instead of 2. Basically, fusion has many options and its fuels are easily accessible.
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Sep 4, 2012 23:50
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Hobo Erotica posted:Added to the OP. I got confused and may have done the wrong thing with Thorium though, office thug, if you want to do a bit on it which a layman would understand I'll put that in instead. There's a lot to talk about unfortunately. Layman understanding may vary. It's long  , so you can add parts you like to the OP if you want.Thorium is used as fuel in what's called a breeder reactor. These reactors use neutron radiation from nuclear reactions to transmute very common fertile isotopes like thorium-232 and uranium-238 (depleted uranium) into new isotopes that can themselves be used as fuel. You thus get a pseudo-catalytic cycle going on where burning fuel goes on to create more fuel. Thorium itself is non-fissile, so it can't be used in weapons. The fuel it's converted into is uranium-233, which like pretty much anything else that fissions, can hypothetically be used in weapons. However this is difficult for the reasons below. There are two ways to use thorium, either as a solid fuel or as a liquid. In both cases thorium has some nice advantages over current enriched uranium fuel, Availability: Much more common than the isotope of uranium we currently use as fuel, being 430 times more abundant in nature. Thorium is currently considered a radioactive waste byproduct of heavy rare earth mining, and is one of the reasons the heavy rare earth industry is restricted in western countries. Thorium itself is harmless in terms of both toxicity and radioactivity. Can be extracted from terrestrial rock economically, making its availability limitless. Waste profile: Because thorium-232 is much lighter than both uranium-235 and uranium-238 currently used in reactors, its chances of absorbing excessive amounts of neutrons to become transuranics is vastly reduced. This makes thorium a cleaner alternative. However it will still produce fission products like radiocaesium and radioiodine when fissioned. Proliferation resistance: The cleaner waste profile also limits the amounts of weaponable isotopes that will be present in thorium waste, like neptunium-237 and plutonium-239. In addition, breeding thorium into uranium-233 also yields a lighter isotope, uranium-232, which is extremely radioactive and cannot be extracted from the uranium fuel once it is created. This isotope requires heavy lead shielded electronics (and people) to handle and can be tracked from space, making it a huge handling hassle for any would-be rogue state. There are some disadvantages as well, Fuel cycle problems: Breeding uranium-233 from thorium is a multi-step process with an intermediate product, protactinium, which must be allowed to radioactively decay to your uranium fuel away from any additional neutron radiation. If protactinium is not isolated from neutrons in time, it will absorb more neutrons and basically kill your nuclear reactions. It can be dealt with but it adds a significant (costly) level of complication. Need fissile starting material: To start the breeding process, you're going to need very enriched uranium (above 20% U-235, compared to conventional reactor grade enriched which is only 5%), or plutonium. The former is expensive while the latter is a proliferation concern. The most common way to use thorium is as a solid fuel additive in light or heavy water reactors. Heavy water is much more expensive with the payoff that it increases your breeding capabilities by a landslide, meaning you can use more thorium while needing less uranium. Thorium is traditionally added to conventional enriched uranium solid fuel, which yields a number of slight benefits, Solid fuel pros: We've used thorium commercially in these types of systems before. Regulations trust solid-fueled water-cooled reactors the most. Lowered fuel cost vs. conventional uranium reactors. Improved waste profile. Solid fuel cons: Advantages are minimal. Reactor safety doesn't improve. Waste becomes extremely radioactive because of the same uranium-232 that makes uranium-233 from thorium unsuitable for bombs. The internet-phenomena method of using thorium is in a liquid-fuel state, typically in molten salt reactors. These systems are true breeders in that once you have bred enough fuel from thorium, you can stop using enriched uranium and just stick with what you've made indefinitely. You can even breed more fuel than what you started with initially. Using thorium in an MSR changes the game quite a bit. http://en.wikipedia.org/wiki/LFTR In this type of reactor, you dissolve your thorium and your uranium in a molten salt kept above 700 degrees celcius (1300 farenheit) by the heat of the nuclear reaction. You get a ridiculous number of benefits from this, Online reprocessing: Fission products can be extracted from the fuel mixture while the reactor is running. This limits the amount of neutron poisons that accumulate in the fuel, and also limits the severity of any fallout that might occur during an accident by a factor of several thousands. In accident scenarios, active removal of fission products also ensures that there will be very little residual radioactivity that would otherwise keep the fuel very hot in a meltdown-style scenario, allowing the fuel salt to expand and cool safely. Waste destruction: Breeders produce an excess of neutrons which can be used to transmute transuranics into isotopes that will readily fission, and subsequently cause them to fission. This means that you can permanently destroy transuranics with these types of systems. You can also stabilize most fission products by transmuting them into stable isotopes. As a result, the reactor will not produce any long-lived transuranic waste and only short-lived fission products, which will last 300 years instead of tens of thousands. The amount of waste per fission will be much smaller as well. Finally, the reactor's fuel could be spiked with current nuclear waste to destroy said waste. Air-cooling: The high operating temperatures of these reactors allows them to be air-cooled instead of water-cooled. That means you can put them almost anywhere on earth rather than being limited to the side of large bodies of water. Air-cooling also makes the reactors more efficient in heat-to-electric conversion, by about 10-15%. Scalability: Molten salt reactors run hot but at low pressures, meaning that they can fore-go the huge pressure vessels that are typically required by water-cooled systems. Some thorium-using MSRs also produce minimal neutron radiation towards the outside world, meaning that the core will not make its surroundings radioactive. These attributes make thorium MSRs highly scalable and viable all the way from the size of a conventional power plant to the size of a dinner table. A dinner table that produces 30+ MWe, enough to power two fully loaded locomotives or a small community. You lose out on efficiency as you scale down (the neutronics become really weird) but it makes your reactor very flexible in terms of siting. Factory production: The small sizes possible with thorium MSRs means that they could be mass-produced in factories. This is the single biggest advantage with these systems in that factory production makes regulatory licensing a lot faster and simpler. Regulations currently account for 70-80% of new reactor costs. Regulations become easier because the reactors are identical and produced from a standard model. This is what France did with its larger scale systems, and how it got up to 70% of its total power to come from nuclear. Isotope synthesis: Thorium breeders are special because they open up new pathways to extremely rare synthetic isotopes. Uranium-233, bred from thorium, is part of the neptunium decay series. You gain access to exotic isotopes like thorium-229, used in nuclear clocks and theoretically possible to use in rechargeable nuclear batteries. It also gives you access to bismuth-213, which is currently the most potent anti-cancer agent known for extremely labile cancers like leukemia. On the heavier side, you get a lot of light transuranics like plutonium-238, which is currently the roadblock to NASA's future planned deep-space missions. A thorium MSR would produce 15 kilos of Pu-238 per 1 gigawatt of electric capacity. For the record, Russians have sold a significant part of their inventory, 14 kilos, to NASA over the entirety of the space program. Cost of operation: Once built, thorium MSRs will be money-printing machines with almost no fuel cost and minimal maintenance costs. The system will pay for itself in isotope and stabilized fission product sales alone. Cannot melt down: The salt is configured to expand as it heats up, helping to dissipate heat from radioactivity as well as stopping chain reactions before they get out of hand. You can also put very simple hands-off systems that will automatically drain your reactor of all its salt into underground passively-cooled containment if for whatever reason you lose power to the reactor or things go awry. The trick there is to use a frozen plug of salt, kept frozen by fans, which will melt as soon as the fuel gets too hot or the fans lose power. Accident mobility is limited: In addition to everything noted so far, the fluoride salts themselves are not very mobile in the environment. Most are insoluble in water, so even if a meteor smashed your reactor into the water table or something, the fuel salt would still not contaminate the local water supply to any appreciable degree. Fluoride salts also solidify once they cool down, locking any radioactive products within them and keeping any mess localized. Unfortunately, it's not all rose-tinted glass either, Cost to build: Thorium MSRs will not be cheap to build. There's no getting around this. The molten salt is a mix of expensive alkali metals like berrylium, the reactor parts need to be made out of a special fluoride/heat/radiation resistant nickel-heavy alloy called Hastelloy-N, and it needs to be a custom melt of Hastelloy which can also resist attack from some fission products in the salt (notably Tellurium attack). The initial starter fuel will need to be uranium enriched to 20% of higher, or plutonium which has compatibility issues with the salt. You also need to figure out how you'll deal with graphite moderator degradation overtime in the reactor salt. Development: These reactors were basically brushed under the carpet 40 years ago by the Nixon administration. The only country that's put serious effort into revitalizing them is China. In addition, most regulatory bodies won't even consider the existence of thorium MSRs because they are simply too different. Regulatory hurdles: This is basically the reason why no one except China is ever going to develop these reactors. Regulations play a huge role in dictating what will and what won't happen. So far it looks like regulations only care about 1 thing: pressurized and boiling water reactors. Everything else can gently caress off as far as they're concerned. Office Thug fucked around with this message at 14:32 on Sep 5, 2012 |
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Sep 5, 2012 14:29
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Rand alPaul posted:Thanks for this post! I was wondering, is India also serious about Thorium? They have the only thorium power plant that I know of. India "was" serious about developing thorium, specifically for use in solid fuel heavy water reactors very similar to the CANDU. Their major reason for doing this is that their access to uranium was limited. They used their CANDU reactors to produce weapons-usable plutonium by illegally cycling their fuel very quickly, and then used said plutonium to make a test bomb. Countries stopped selling uranium to them after that so they were forced to scrounge up what little uranium they had access too so far while shooting for thorium as an alternative. Their interest in thorium may have changed recently when the US decided it was going to start selling uranium to India again. I think they're still going to go for thorium but probably not as strongly as before.
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Sep 6, 2012 13:02
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spankmeister posted:Yes I should have been more clear about this but I did not mean to say that there is a huge risk of anyone turning these into a dirty bomb. (Well, some idiot might try anyway) but more that these materials can be quite dangerous and should be kept out of the hands of the general public. If you can make a dirty bomb you can also make a chemical bomb. The difference is the latter is much lighter, far less expensive, easier to infiltrate into places, and actually works terrifyingly well. A single nerve gas bomb could clear a quarter-square mile radius of all life in less than ten minutes. And there is very little anyone could do about it in such a situation.
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Sep 12, 2012 13:06
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schmen posted:My main concerns are what would the sort of feasibility be for a generator like this? Most of the time they're used for space probes and missions (cause 80 year half life pretty drat good for fuel), but on the ground you could maintain and replace them without too much trouble I would think, not to mention upgrade them when needed or simply replace in a controlled way. The availability of the fuel would be a roadblock to killowatt applications. In a very well-designed, extremely efficient breeder that could take something common like depleted uranium or thorium and fission all of it, you would expect at most 6.8% of your waste to be Sr-90 (http://en.wikipedia.org/wiki/Sr-90). And unlike Am-141 and Pu-238, you can't design a reactor to produce Sr-90 specifically. Am-241 and Pu-238 have their own issues as well. Pu-238 is extremely challenging to make with either U-235 or Pu-239 fuel cycles, while not so much with the Th-232 cycle which unfortunately nobody is using seriously. There's currently a shortage of Pu-238 which is one of the things keeping NASA from taking on projects that go beyond the asteroid belt. Pu-238 is a largely a relic of cold-war era nuclear materials breeding programs. Today it's a huge hassle to make more because it requires that we reprocess spent nuclear fuel for Np-237, which could technically also go into making a rather effective (highly pure) nuclear weapon (http://en.wikipedia.org/wiki/Pu-238). Am-241 is a decay product of Pu-241, half life 15 years. What doesn't help its case is the fact that Pu-241 is created in minute amounts on top of the fact that you need to let it age to get to Am-241. Ultimately the availability of these isotopes is going to depend on how many reactors we have and how we deal with our nuclear wastes. The US currently does not reprocess any of their waste outside of military applications, which severely limits them on the front of RTGs. You'll also have to strike a balance between having worth-while products and actually producing energy from your reactor. Designing a reactor for high transmutation ratio typically comes at the cost of being left with a reactor that doesn't so much make energy as it does hog it from other plants just to stay online. And there's also the possibility of just building a small modular reactor instead of a big RTG (http://en.wikipedia.org/wiki/Small_modular_reactor). You can't make battery-sized fission reactors (due to neutron flux issues) but you can still make them pretty darn small. Office Thug fucked around with this message at 16:37 on Sep 12, 2012 |
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Sep 12, 2012 16:31
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schmen posted:Ah thanks very much for that, I'm actually not all that educated about the waste and all of nuclear reactors, I knew wasn't easy to get all the isotopes, but wasn't aware that it was such a pain to get it in the first place. The SMR is an answer to nuclear's ultimate problem: regulatory costs (http://www.phyast.pitt.edu/~blc/book/chapter9.html). The gist of it is that instead of building large plants that take several years to complete and are prone to regulatory changes and economic uncertainties during construction (elevating their cost to ridiculous levels), you can build a bunch of small plants on a factory line as quickly as possible and avoid the brunt of economic uncertainties. This also has the advantage of standardizing your reactors. Instead of having a bunch of different reactors that all need their own lengthy licensing process, you build one reactor as a "standard" and get that licensed, and it more-or-less speaks for the reliability of all the other reactors you're going to build identically, which greatly reduces licensing costs. The disadvantage is that smaller nuclear plants end up being less fuel efficient than larger ones, and won't be as flexible in terms of on-site waste management and generator capabilities. But you'll end up with a fleet of reactors that basically costs 25-30% of what it takes to build singular large units.
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Sep 13, 2012 12:41
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I guess I just like the idea of having a reactor where you don't have to fuel it for decades, instead of lovely coal like Australia has way too much of right now.
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Pvt Dancer posted:The location of a nuclear plant depends pretty much only on water availability for cooling, that's why they're all close to sea / rivers / lakes. Transmission losses are pretty small for the first few hundred km. You need water for conventional plants, yes. For high temperature systems, you can get away with air cooling.
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Sep 17, 2012 22:56
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Nuclear waste is a common topic. There are ways to destroy this stuff permanently: http://en.wikipedia.org/wiki/Nuclear_transmutation Essentially you use nuclear physics to change the nuclei of isotopes you don't like. If you irradiate waste with neutrons of the right energy, you can force them to capture the neutrons, which turns them into a different isotope. A single neutron can mean the difference between something needing thousands of years to stabilize and something that stabilizes so fast it's difficult to measure accurately. That's how you deal with most fission products. The only exceptions which are present in high amount are Sr-90 and Cs-137. But these guys don't last long (300 years for 10 half lives) and only make up ~20% of your total waste mass. They're also easy to isolate and manage from everything else. With transuranics, you irradiate them to create "fissile" isotopes out of them. That basically means that the next neutron that hits them is likely to cause a fission event. The process is sometimes dubbed "transmuting into oblivion". Generally, odd-numbered isotopes are fissile. The big 4 that produce an excess of neutrons are U-233, U-235, Np-237, Pu-239, with everything else producing less than 2 neutrons. It gets a lot more complicated than that but suffice to say if you can fission any of those big 4 with high efficiency, you're left with more than enough neutrons to burn surrounding transuranic waste. You also avoid creating new transuranics if you ensure the highest possible fission efficiencies with your fuel. This all depends on how slick your reactor is. What's most likely to happen is we'll use "plasma furnaces" to destroy our waste. Basically, we use highly neutron-dense fusion reactors to produce all the neutrons needed to transmute things. The issue is that such reactors will be energy hogs and quite expensive to operate, but they'll also be able to do a lot more than just burn waste. This is basically what a couple companies in China is planning to do: http://www.world-nuclear.org/info/default.aspx?id=26187&terms=china quote:Wastes In the meantime though, that waste can't sit in cooling ponds forever. That's where our decision on dry casking and repositories come into play. It's not to say the waste will stay in casks forever, just that we're not done developing the systems we'll need to destroy them permanently so this is something we can do in the meantime that's much more secure.
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Sep 19, 2012 16:18
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Doom Rooster posted:Yeah, I remember in the Nuclear thread someone posted a study which stated that accounting for increased energy consumption, we would be out of "easily accessible" Uranium in about 1000 years(without reprocessing, which would add a huge increase in efficiency). Thorium is another possible option, and is drastically more available than Uranium is, so nuclear energy could carry us a good, 20,000 years conservatively estimating? We might run out of cheap uranium-235, which makes up 0.7% of natural uranium and is the primary fissile fuel we burn right now. We are not going to run out of cheap uranium-238 (99.3%) or thorium-232 (100%), period. Uranium can be extracted from sea-water at a very low price, and thorium can be extracted from granite and other rocks for next to nothing. It's all doable because nuclear produces an enormous amount of energy from very little. Extracting even a single gram of fuel from a tonne of rock yields several times more energy than burning a tonne of coal, and for thorium that process is cheap and catalytic.
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Nov 13, 2012 18:13
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Hobo Erotica posted:Yeah fair point. Uranium/nuclear has its problems too of course, and my point was more to say that just cos it's got a high energy content doesn't mean it's immune to the problems of mining. I did say it's probably better than coal though. Uranium is miles better than coal, no question. Here's a post I made in the nuclear thread: Office Thug posted:There's some good figures here for the amounts involved in uranium fuel fabrication: http://www.world-nuclear.org/info/inf03.html We're talking about mining on a scale ten times bigger for coal than what you get in the worst cases for uranium, down to a factor of 200 when the richest uranium ore deposits are concerned. We also can't rule out Gen 4 reactors that support fuel breeding cycles, such as thorium and plutonium reactors. They use the far more common fertile isotopes found in nature as a feedstock to producing energy, rather than using ultra-rare fissile isotopes like uranium-235. As far as concentrated uranium deposits are concerned, we can easily expect a further reduction in mining by a factor of over 200, as we'll be moving from something that needs to be enriched to 4-5% from 0.7% natural concentration (U-235), to something that is 99.3% (U-238) and which requires no enrichment. In contrast, we could get thorium from pretty much anywhere cheaply and with less mining/drilling involved than what we find in coal and oil. This post has some figures based on limited calculations: http://energyfromthorium.com/cubic-meter/ And this study details the cost of thorium and uranium recovery rates from granite and at what costs: http://www.ornl.gov/info/reports/1963/3445600230925.pdf Thorium is ridiculously easy to leach out of things, whether intentional or not. The rare earth industry actually has a problem with thorium because it precipitates readily in the first couple steps of rare earth extraction. Although thorium is only slightly radioactive, it's still considered nuclear waste in the west. China has mountains of thorium that they're stockpiling for when they eventually finish developing their pebble-bed molten-salt cooled thorium reactor, followed by their liquid fluoride thorium reactor.
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Nov 15, 2012 16:14
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Quantum Mechanic posted:I was comparing the capital cost of the plants per GW based on under construction plants - the AP1000s mentioned above. The 3-4c figure as far as I am concerned is not applicable to countries that, you know, pay their workers a fair living wage. I'm sure China could construct solar plants for billions less as well. The cost of nuclear has very little to do with pay and fair labor and everything to do with construction delays and uncertainties caused by regulations: http://www.phyast.pitt.edu/~blc/book/chapter9.html quote:From this analysis we can understand two more important reasons, besides skyrocketing labor prices, that explain why costs of nuclear plants completed during the 1980s were so high: their construction times were much longer than in earlier years, and they were being built during a period of high inflation. Emphasis from source. Inflation played a role in costs, but it was amplified by delays and sudden design changes decided on by the NRC. Don't get me wrong, regulations are one of the reasons for the unparallelled safety ratings you find when looking at nuclear industry workers and plants. Regulations are absolutely necessary here just like they are everywhere else. But there is such a thing as inefficient and sloppy regulations and this is basically what we find in nuclear regulatory agencies in most western countries. Also note that in western countries, regulatory commissions are heavily politicized. The cancellation of the Yucca Mountain project is a prime example of this. George W. Bush appointed this prick specifically to thwart and cancel the repository, which wasted billions (from both the private industry and the tax payers) and led to further fallout in the DOE and NRC: http://www.world-nuclear-news.org/-RS_NRC_suspends_final_licensing_decisions_080812a.html There are ways to get around the brunt force of delays and sudden design changes, such as building standardized reactors (see France) or factory-line production of small modular systems. It's been made pretty clear that some countries don't want nuclear plants, or at least, don't want more of them no matter how potentially cheap and safe they get. In those cases, you'll be stuck with renewables and your main worry will forever be trying to reach grid parity with them. You'll get there eventually but probably not within the next 50 years.
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Nov 16, 2012 16:34
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Quantum Mechanic posted:Office Thug your link was from 1990 and in the same page specified that total labour costs from 72-88 rose nearly five-fold. Increase in labour costs is perfectly normal when it comes to the construction of any plant. It's all factored into the EEDB. What is not normal in nuclear's case is the increase in length of time required to complete the plant, from 7 years in 1972, to 12 or more in 88, which translates to a multiplacative increase in the total cost of the plant when you factor in EEDB with interest and inflation related costs. You can fix this without touching regulations by building reactors so small they can be assembled on factory lines and delivered in one piece to wherever they need to be installed: http://en.wikipedia.org/wiki/Small_modular_reactor. Factory assembly requires standardization, which means your reactors are all identical and easier to license and inspect as well. However, if regulations can't get their act together and figure out how to license something that isn't a pressurized light-water uranium-235 700 MWe+ nuclear reactor, then there's no real solution to the problem to begin with. Except what people are doing now, which is not building any more new nuclear plants. And this is a bad thing because: Quantum Mechanic posted:Regardless, Australia would have the same regulatory situation, and if you want to add "relaxing nuclear regulations" to the list of things that would need to happen before we went nuclear we'd be waiting until the Earth turned into Venus. Earth will turn into Venus at this rate regardless, since renewables are not cutting into the market fast or cost-effectively enough to usurp fossil fuels.
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Nov 18, 2012 22:10
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Quantum Mechanic posted:Office Thug, I understand that the labour costs are factored into the cost of the plant, but that was part of my argument for why China's nuclear costs are not comparable to the US or Australia. There are some very comprehensive studies out there on the economic status of SMRs: http://www.oecd-nea.org/ndd/reports/2011/current-status-small-reactors.pdf It's true that the overnight cost of SMRs will be higher on a cost-per-capacity basis (p. 20). However, the cost-advantage of rapid deployment and licensing in over-regulated countries makes SMRs generally economical compared to building larger nuclear plants, except in pacific-asian countries where SMRs would only win out where large nuclear plants can't be installed (p. 22). Data for projected costs of other power plants was taken from http://www.iea.org/Textbase/npsum/ElecCost2010SUM.pdf. Note that the costs assume a carbon tax of 30 USD/ton CO2. Office Thug fucked around with this message at 15:42 on Nov 19, 2012 |
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Nov 19, 2012 15:38
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Also for those arguing about solar, please be careful not to confuse GW, which is theoretical capacity, with GWe, which is generated electrical capacity. All power plants are affected by a capacity factor which is largely set in stone for renewables due to environmental conditions such as night time or lack of wind. Renewables also have to contend with immense problems when it comes to load-following. Not only do you need to instal a large surplus of renewable capacity to generate the required amount of real-world electrical capacity, but you also need to instal a large surplus of intermittent storage capacity if you want to use all that electrical capacity when you need it and keep the grid stable. Load-following is something that cannot be ignored. Diesel generators and open-cycle gas plants are our most used options right now, but they're expensive and happen to be more polluting than other options whenever they're used to support renewables. There's a myth that nuclear plants can't load-follow, but it is physically possible with some planned heavy-water designs getting down to 75% full power (http://www.nuclearfaq.ca/cnf_sectionA.htm#load-follow). The main issue with nuclear isn't fuel either, it's building the reactors. Construction is a long-drawn and expensive process today. Developping current designs into small modular reactors would considerably shorten that time, and thus their expense, on top of everything else. If you think ahead of that, you get into fuel breeders and those things have practically no fuel costs due to the shear abundance of the fertile nuclear materials they use. They also tend to be far safer due to the finickiness of breeding cycles. LFTRs and IFRs are breeders, although my money is on the LFTR since plutonium breeders have a history of not working out very well (it doesn't help that plutonium breeding and fissioning requires 2 completely different neutron "speeds", which really limits your coolant choices and core geometry to less-than-ideal things like liquid sodium). Office Thug fucked around with this message at 21:36 on Nov 20, 2012 |
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Nov 20, 2012 21:31
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Quantum Mechanic posted:This is untrue, at least as far as CST goes. Increasing the capacity factor of CST for a given region is as simple as building more salt storage and receiving towers. Overbuilding to compensate for capacity factor does not change the capacity factor, just the capacity and in turn the electrical outputs achievable. You still need to build in excess to make up for the intermittent nature of renewables and that's my point when I'm talking about how theoretical capacity does not equate actual averaged-out electrical capacity. If your goal is to replace peak-time and intermediate sources in the grid, then solar is not a bad deal despite its capacity factor because its peak production times coincide with some of our peak demand times (if you can make it cheap enough to even be an option). However, for around-the-clock baseload production you are going to need to build way more than what is ideal one way or another because of the fact that the sun sets at night and your thermoelectric storage systems are far from perfect in terms of efficiency. Flaky posted:This is just flat out wrong. Solar power directly cuts into the peak energy use period (the middle of the day) and displaces carbon emitting fuel sources 1:1. You will always use all of the renewable energy available to you, because it costs nothing. Then you will meet demand with fossil fuels until the point at which storage and network limitations of renewables are overcome. You never ever turn off a solar PV unit. Solar is not free and it turns off at night so I don't know what you're on about. You need to build solar plants, and like nuclear, construction costs can be very high although for very different reasons. Renewables can be more economical than peak-time energy generation like diesel and closed-cycle gas turbines. But unlike renewables, you can keep those running around-the-clock just as well as baseload sources, however diesel/open-gas are less cost-efficient than coal/closed-gas/nuclear. The reason we use them instead of baseload options is because you can throttle them fast enough to keep up with grid demand, basically out of necessity. If peak production time on renewables matches that of diesel/open-gas, then it's not absurd that renewables would win out even if they needed a little bit of backup capacity just in case. They don't need to run 24/7, just at times when you need them. Replacing baseload options like nuclear and fossil fuels is assuredly not economical because renewables can't run around-the-clock without installing far more capacity than what's actually needed, on top of having to instal intermittent storage, all to make up for their uncontrollable productivity. Germany realized how expensive their renewable dreams would be and had to build more coal plants instead of "smart grids" and all that rubbish after they shut off a good chunk of their reliable nuclear electric generation. In the meantime they have to import electricity from France, ironically enough. People still contend that renewables may one day be cheap enough to replace everything after problem X, Y, Z, and whatever else are somehow solved in a perfectly economical manner. While I contend that nuclear is already more economical if you're willing to restructure regulations a little to support standardization (see France), which is both much safer and several times more economical than building "special snowflake" plants everywhere. And if you're bold, develop SMRs to speed up deployment and further reduce cost. You wouldn't even have to touch anything particularly new like Gen 4 designs, just change the way you build plants.
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Nov 21, 2012 17:08
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The Chinese don't use their own produced solar capacity despite taking a total "gently caress the environment and let's make this economical" approach to building them because it's still over twice as expensive as pretty much anything else they can build for themselves right now. In 2007, they exported 99% of their built solar cell capacity. http://en.wikipedia.org/wiki/Solar_power_in_the_People%27s_Republic_of_China Granted, they're world leaders in renewable usage despite all that, with a good portion of their power coming from hydroelectric dams and with plans to fill their offshore wind capacity up by the half point of this century. They can afford to do that with a monopoly on neodymium and dysprosium heavy rare earths. Speaking of which, heavy rare earth availability is a tremendous problem in any western country hoping to build large renewable systems, especially wind turbines. Ironically enough, it's due to nuclear regulations: https://www.youtube.com/watch?v=tyqYP6f66Mw Heavy rare earth minerals contain very large quantities of thorium and decent quantities of uranium. Although uranium yields are a good thing and any produced uranium can be sent off to enrichment and fuel fabrication, thorium is unusable waste which is costly enough to deal with that most mining companies have stopped bothering with heavy rare earths. Thorium isn't particularly dangerous mind, it can be chemically stabilized and stored as a nitrate, and it's an extremely weak alpha emitter. But it's radioactive so there's a lot of regulatory hoops to jump through and waste management fines involved whenever you produce it. Keep in mind that you could build solar and wind plants without heavy rare earths, but their cost is generally higher in comparison to PV solar and RE wind turbines in a rare-earth saturated market like China's. Solar thermal is the best example I can give. Its thermoelectric efficiency is limited to steam turbines (which requires an external water loop for cooling, which by the way is quite rare in deserts) unless you scale it up to a ridiculous size that can accomodate gas cooling, but current molten salt storage systems won't support those temperatures. Its cost compared to solar PV, wind, and nuclear will depend on how the state deals with China and how bad their nuclear regulations are, but solar thermal's cost compared to coal is generally 2.5 times higher than coal pretty much everywhere. http://en.wikipedia.org/wiki/Cost_of_electricity_by_source I know there are claims of solar thermal reaching grid parity but I don't see how that could happen, ever. If you manage to make solar thermal more efficient somehow, there isn't anything to stop you from doing that with coal or nuclear or anything else that's based on the rankine cycle. The turbine and energy storage systems are your biggest problems, and those can be adapted into other heat-electric plants just as well. Energy storage could enable extra cost-effective coal capacity to be stored at night and used during peak hours in the day, effectively making it a possibility for meeting intermediate and peak energy demands. And I suspect this is exactly why Australia is pushing so hard for solar thermal.
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Nov 23, 2012 18:21
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Pander posted:Eh. Right now I stand at "Nuclear is the best way to generate electricity (eliminate coal, use nat'l gas for heating, use oil only for peaking), oil makes for the best transportation, and hopefully we can develop incredible batteries (hydrogen fuel cells? Others?) to allow renewables to also develop electricity and oil to be less required. The best large scale batteries would be liquid metal batteries or flow cell batteries. Both of those types are modular, cheaper per capacity than lithium ion, and last far longer than lead acids. Liquid metal systems are already on the market, while flow cells are getting there. My money would be on flow cells in terms of solving both the large scale and transportation intermittent energy problems. Particularly organic-based flow cells which use ionic liquid solvents for their catholyte and anolyte. They can't pack as much energy as your typical lithium ion battery, but they stand to be much cheaper, much more stable, extremely long-lasting, and very fast in terms of cycling rates. Some organic flow cells have been reported with cell chamber charge/discharge cycle times of just under 2 seconds, which is basically on similar levels with capacitors and things like that. The power rate for these systems is ridiculous. The only issue with flow cells is that you need a solvent, and that solvent adds unnecessary mass and volume to the system, robbing them of their energy density/specificity. However, if you were to make it so the catholyte and anolyte compounds themselves liquid in both charged and discharged states, you could practically overlook the use of solvents and have something closer to a solid-state lithium ion battery in terms of energy density and specificity. This is totally doable with organic-based systems, as organic compounds can be modified with the addition of things like aliphatic chains to depress their melting point without affecting their electron structure too much. Hobo Erotica posted:I wouldn't say I'm fixated on solar specifically. You'll have to dig a lot of things up to build solar plants.
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Dec 5, 2012 18:17
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In other news, South Korea has a growing spent nuclear fuel problem and would like to be able to reprocess it to diminish the volume of stuff destined for permanent storage by a factor of 20. Of course, the US won't have that because reprocessing = bombs. http://finance.yahoo.com/news/nuclear-waste-growing-headache-skorea-092702110.html quote:North Korea's weapons program is not the only nuclear headache for South Korea. The country's radioactive waste storage is filling up as its nuclear power industry burgeons, but what South Korea sees as its best solution — reprocessing the spent fuel so it can be used again — faces stiff opposition from its U.S. ally. Some further discussion regarding why the US has such weird policies regarding other countries reprocessing their spent fuel: http://www.nucleartownhall.com/blog/william-tucker-living-in-the-nuclear-past/ It's all sorts of ridiculous when it's patently impossible to make weapons out of the spent-fuel plutonium South Korea has, even if it is seperated because it's always left in the reactor long enough that the isotopic mix of plutonium you get is totally useless. The only way you could get weapons-useable plutonium would be to cycle the fuel rapidly. That only really happens if there's a decision made on a political level to instruct operators to do it, because there's no advantage to fast-cycling fuel other than producing plutonium for weapons. The US is also telling SK not to enrich uranium on their own soil, again because weapons. And again leaving out a crucial step, which is that you need to enrich uranium far beyond what's necessary for reactors to make it suitable for breeding (20%+), and to impractically costly levels to make it directly useable in weapons (85%+). Breeding nuclear fuel involves 20% uranium, but just as a sort of "matchstick" to get things going. Breeding cycles produce an excess of neutrons that generally perpetuates the cycle so long as fertile fuel is continuously fed into the system. The plutonium cycle is well-suited for weapons because you get more plutonium in the end than was required to make it with the fuel cost being U-238 or "depleted" uranium, which happens to make up 99.3% of natural uranium. In any case, plutonium doesn't breed itself. You need a specific reactor for that which adds yet another step between 20% uranium and weapons if that's what a country's trying to do. If you're breeding for energy production you end up with plutonium that's again too isotopically dirty for weapons (but a LOT of energy at negligible fuel cost). Breeders can also run on thorium by converting it into U-233, and they also need 20% uranium to start up. U-233 isn't produced in very large excesses and there's some extra complications that make it difficult to covertly produce for weapons-use. Bottom line is that unless the country wills it, a terrorist group can't just nab plutonium extracted from spent fuel and use it to make a garage-weapon. The country has to really shoot for it to make weapons-grade material, and that's basically what the US is accusing South Korea of trying to do in this. They're understandably upset about the whole affair.
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Mar 28, 2013 17:52
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Morbus posted:Not to nitpick too much, but "reactor grade" plutonium (that has been contaminated with large amounts of Pu-240) isn't "totally useless". It has a high rate of spontaneous fission which poses several design challenges, however with a good implosion system you could definitely fashion a working fission bomb out of it. The main challenges would be the high thermal output, and radiation exposure to those working with it (once in the bomb itself, the heavy neutron reflector and tamper necesary to implode such a core effectively would shield most radiation). To be sure, it is a pretty dumb material for a fission bomb, but that wouldn't necessarily stop a country from using it if all they wanted was a show-off weapon, and they didn't have access to U-235 or Pu-239. In fact, the US actually built and tested (successfully) such a device in 1962 (http://tinyurl.com/cum7prs). The yield is classified ("less than 20kt"), but as discussed more below, any country with abundant Pu-240 would have a straightforward path to greatly increasing that yield. That was a really informative post on the subject. Thank you! I just wanted to add that the plutonium they used in this test came from a MAGNOX reactor in the UK (http://www.ricin.com/nuke/bg/bomb.html), which was specifically designed to operate in both civilian and weapon mode when necessary. At the time, only two grades of plutonium were decided: weapons-grade, which contained less than 7% Pu-240, and reactor-grade which contained more than 7% Pu-240. Today, there are three grades, fuel grade covering 7-19% Pu-240 and reactor grade being anything with more than 19% Pu-240. What they got from the MAGNOX reactor was fuel-grade plutonium. All conventionally-cycled LWR and BWR spent-fuel plutonium is reactor-grade, containing more than 19% Pu-240. There is no record of anyone ever successfully making a weapon out of reactor-grade plutonium. Not a drop of spent-fuel plutonium from LWRs and BWRs in the US ever went into a successful weapon for instance, all the pure stuff they ended up using came from military fast-breeders. It's extraordinarily unlikely for anyone that doesn't have national support to get their hands on everything needed to build weapons. So when a country like the US tries to limit a nation's declared peaceful nuclear program due to proliferation concerns it can get pretty touchy. silence_kit posted:Edit: To actually respond to your post, although it is off topic to what I wanted to say in this thread, one obvious difference between employing new technologies in nuclear and solar is that the time in between new improvements in solar and rolling it out into new panels is much less than in nuclear, where it takes many years and many dollars to build a plant. You wouldn't need to do any R&D to make nuclear more economical than solar, since it already is even at 0.5-1.2% total efficiency. In the same time frame and with the same funding it'd take to have solar reach grid parity, we could have those Gen IV systems that get 30+% total efficiency and that can run on non-enriched fuels. But we wouldn't even need to do any R&D to make nuclear as competitive as it was in the 70s; standardizing one of the current designs and mass producing it like what France did would be enough to make it cheaper than coal again. Building nuclear reactors back in the 70s was 3 times faster and 4 times cheaper than today. Nuclear reactor construction costs have quadrupled in the west almost exclusively because regulations have gotten really sloppy: http://www.phyast.pitt.edu/~blc/book/chapter9.html In all honesty, there's no reason not to shoot for every option that's theoretically viable. R&D is cheaper than people make it out to be, even when it's nuclear-based, and it's terrific for developing expertise in an industrial economy.
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Apr 1, 2013 18:52
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This came up recently, a 2 and a half hour tour of Oakridge National Labs nuclear department and its projects. https://www.youtube.com/watch?v=8hA8V8y52BM The whole thing is great just for all the technical engineering details that are presented. The commentary on political and economical difficulties of conducting nuclear R&D today is something I found really interesting, starting at 45:16. I haven't finished watching the whole thing yet but I highly recommend it to anyone that's curious about nuclear research.
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Apr 10, 2013 14:52
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Frogmanv2 posted:I understand all this. You're thinking about a expanding energy as a social non-profit service. However social services also need to at least break-even in terms of cost-vs-state funding. Jobs don't mean much if they are economically unsustainable either. Cost overruns can hit private projects just as much as state ones.
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Apr 17, 2013 03:50
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Solid-phase systems like Li-ion or lithium-air are simply not meant for this kind of stuff. They have high energy densities but literally nobody cares about that when it comes to anything stationary. Instead we look at their cost and reliability. Do they rip themselves apart when we try to cycle them too deeply or too quickly? If we hook them up in a series and one of the middle ones fail, limiting the rest of the series, will it be an easy fix? Do they explode/catch fire when they do fail? And so on. Anything that uses lithium has a propensity to be either super expensive or super fragile, or both. We use lead-acid batteries right now because they're low-cost and can withstand more than 10,000 cycles, and, well, that's about it. They can also cycle very rapidly which is why cars use them to start their engines. However, their cell potential and capacities are atrocious, which is why they don't get much use otherwise.
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May 16, 2013 15:50
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Paper Mac posted:Is anyone looking seriously at nickel-iron cells? I remember reading that they're useful for some off-grid type applications, but that they're otherwise not great- any room for improvement? Nickel-iron is kind of done in terms of improvement. We could make minor advances in terms of self-discharge prevention, making the non-active cell systems with lighter/cheaper materials, etc., but that's about it. Their nominal capacity and cell voltages are reachable at acceptably high cycle rates and with deep cycling. We've essentially reached what is conventionally possible with them in terms of theoretical capacity/cell voltage, so that's that. Lithium systems, flow cells, and liquid cells, in contrast, still have a long way to go before we've reached their limits at high rates and near-ideal cell voltages. Theoretically, they are vastly better than lead-acid and metal-hydroxide cells in terms of capacity and voltage.
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May 18, 2013 20:00
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CombatInformatiker posted:Andrea Rossi's E-Cat might not be a scam after all Rossi has a history of badly conducting experiments, continuously sidestepping calls for proper review and outside attempts to replicate his claims, and weird experimental secrecy that rightly makes him a scam-artist rather than a scientist to his peers: http://phys.org/news/2011-08-controversial-energy-generating-lacking-credibility-video.html Also, he is not conducting the right experiments to substantiate his claims. Again. The single most solid evidence for a nuclear reaction is isotopic analysis of the reaction products. It's piss easy to do, literally anyone can send a sample off for analysis at a mass spectrometry lab for a fee and it will tell you exactly what elements you have and their isotope ratios. If the ratios are not natural, congratulations, you now have evidence that this sample was subjected to a nuclear reaction of some sort. Rossi has repeatedly dodged doing things like this and instead based his entire argument on extremely poorly-conducted calorimetry experiments. There are also valid reasons to be skeptical of cold fusion. Nuclear reactions have tremendous energy barriers many orders of magnitude higher than any of the interactions we're used to seeing in chemistry. Trying to use some sort of chemical interaction to cause a fusion reaction is like trying to knock down the empire state building with a mosquito.
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May 24, 2013 17:25
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CombatInformatiker posted:Do you have reasons to believe that this experiment was conducted poorly? I'd love to know if they made an error! Too bad they don't provide sufficient amounts of control data to even figure out whether they can read their instruments correctly. CombatInformatiker posted:Do you have a problem with the experimental setup or the measurements? Do you have a justified reason to believe Rossi manipulated the experiment? If yes, please tell us. If not, spare us the As a regular user of differential scanning calorimetry I have a lot of problems with their measurements, actually. Follow along: http://arxiv.org/ftp/arxiv/papers/1305/1305.3913.pdf Starting on page 3. quote:The E-Cat HT-type device in this experiment was a cylinder having a silicon nitride ceramic outer shell, 33 cm in length, and 10 cm in diameter. A second cylinder made of a different ceramic material (corundum) was located within the shell, and housed three delta-connected spiral-wire resistor coils. Resistors were laid out horizontally, parallel to and equidistant from the cylinder axis, and were as long as the cylinder itself. They were fed by a TRIAC power regulator device which interrupted each phase periodically, in order to modulate power input with an industrial trade secret waveform. This procedure, needed to properly activate the E-Cat HT charge, had no bearing whatsoever on the power consumption of the device, which remained constant throughout the test. This is what's called a "closed-system", meaning that energy can go in and come out of the system. They're saying that they supply a specific amount of AC current electrical power to the device through internal resistors in order to activate the device. That's going to be important to keep track of because if they don't whose to say they aren't just mistakenly heating the tar out of it with electrical current? To substantiate the underlined claim and to demonstrate that they know what they're doing, they would monitor the input or at the very least conduct a blank test to refer against, and report that data alongside their other runs. Moving on to see what they did on page 5 quote:Electrical measurements were performed by a PCE-830 Power and Harmonics Analyzer by PCE Instruments with a nominal accuracy of 1%. This instrument continuously monitors on an LCD display the values of instantaneous electrical power (active, reactive, and apparent) supplied to the resistor coils, as well as energy consumption expressed in kWh. Of these parameters, only the last one was of interest for the purposes of the test, which was designed to evaluate the ratio of thermal energy produced by the E-Cat HT to electrical power consumption for the number of hours subject to evaluation. The instrument was connected directly to the E-Cat HT cables by means of three clamp ammeters, and three probes for voltage measurement. They're only measuring kWh and voltage, which is fair if they monitor it throughout the experiment and report it alongside their other calorimetry measurements. Unfortunately, all they really say about that whole affair in regards to the December test is strewn here and there throughout the first 15 or so pages. Here's a bit on page 6: quote:Upon conclusion of the test, the recordings from the video camera were examined. By reading the images reproducing the PCE-830's LCD display at regular intervals, it was possible to make a note of the number of kWh absorbed by the resistor coils. Subsequently, the E-Cat HT's average hourly power consumption was calculated, and determined to be = 360 W. The average consumption is 360 W. The next incidence that mentions input power is on page 13. There we find the chart "Produced vs Consumed Power". Except for thermal energy production, there is no sign of where anything else is coming from. Here's their description: quote:Plot 2 shows produced vs. consumed energy. Radiated energy is actually measured energy; total energy also takes into account the evaluation of natural convection. Data are fit with a linear function, and COP is obtained by the slope. I assume the extra 7.5 or so kWh of energy they get at 32.5 kWh electrical input in their Total energy is natural convection, which they evaluated to be 41 watts (I think, from their air temperature calculation on page 10). It comes out to 4 kWh, so they're missing another 3.5 kWh to explain the 32.5 (electrical input) + 7.5 (unaccountable extra energy) kWh gap between total energy and thermal energy in that graph. They chalked it up to random error which they just assumed is 10%. I finally found another number for electrical input and it was, again, just a single number: 360 watts over 96 hours. quote:The device subject to testing was powered by 360 W for a total of 96 hours, and produced in all 2034 W thermal. This value was reached by calculating the power transferred by the E-Cat HT to the environment by convection and power irradiated by the device. So far, there is no way of telling whether they can even run a calorimetry experiment without messing it up. There's no control. We have no idea what their input is really like other than it's an average 360 W. The fact that we can't tell whether they know what they're doing or not is several magnitudes more damning than knowing that they did mess up, because at the very least peers would be able to tell them how to run it better next time. Here, we can't even tell if they know how to measure electrical input into a couple of heating elements correctly because there's simply no data, no control, nothing. Now the March test. Here they actually do run a blank or "dummy". Unfortunately they don't actually run their dummy the exact same way as the loaded system (which ran on a "self-sustaining mode" of ON/OFF electrical input, while the dummy ran on continuous input). They ran it to calibrate their actual experiment. There's nothing interesting to talk about other than the data they bother to report being difficult to follow. Eventually we get to page 22 where things rapidly deteriorate thereafter: quote:Ragone Chart It really grinds my gears when people fail to report the mass of their reactants and products in their chemistry papers, leading me to somehow elucidate what the gently caress they even did, and then have some bullshit reason for not doing it. I realize this isn't a chemistry paper, but this is still one hell of a bullshit reason not to take the time to figure out how much stuff was even involved in their amazing cold fusion reactor. The manufacturer took it to their secret factory and won't give it back. That's amazing. When I build and test a battery I don't just throw whatever quantity of electroactive material in it, cycle it, and send it back to a manufacturer to remove the internals and then weigh the empty casings I get back to figure out how much poo poo I put in the battery in the first place. And consequently, realize the mass I get is so far off that I just make up a number for reporting. But that's exactly what these guys did apparently. They didn't even bother to collect and weigh their product, of course, so it's no wonder they never get this stuff properly analyzed to substantiate their claims of nuclear reactions. Or maybe it's because the group learned their lesson the last time they tried to gently caress with nuclear physicists. There are some things you just can't fake. Unnatural isotopic ratios happens to be one of them. Same page, the next paragraph is even worse: quote:According to the data available from the PCE-830 analyzer, the overall power consumption of the E-Cat HT2 and the control box combined was 37.58 kWh. The associated instantaneous power varied between 910 and 930 W during the test, so it may be averaged at 920±10 W. In order to determine the power consumption of the E-Cat HT2 alone, one must subtract from this value the contributive factor of the control box power consumption. As it was not possible to measure the latter while the test on the E-Cat HT2 was in progress, one may refer to the power consumption of the box measured during the dummy test. This value would in all likelihood be higher in the case of operative E-Cat HT2, due to the electronic circuits controlling the self-sustaining mode: so, as usual, we shall adopt the more conservative parameter. We finally find out the other reason for why they ran that dummy test, and it was to avoid having to measure the electrical input for the real test for reasons I have yet to determine. I am extremely skeptical of their claim that they couldn't possibly measure the control box consumption while this thing was running. What I can say is that they're stating they never bothered to properly measure the electrical input for this test, and that just won't work here. Not with calorimetry. This is precisely what I mean with "poorly-run". It just keeps getting worse quote:Let us further assume an error of 10%, in order to include any possible unknown source. 10% error is, indeed, passable for calorimetry of this scale. Unfortunately, 10% error is still 10% error. It's still gigantic and that's the sole thing they're basing their claims on, and they don't even know if it really is 10%. Sometimes it can get as high as 30% in non-isolated calorimetry like this. They should not fool around with this stuff and just assume it's 10%. From here on there's more assumptions and comparisons to chemical systems. Ending off with the concluding remark on page 28: quote:The March test is to be considered an improvement over the one performed in December, in that various problems encountered in the first experiment were addressed and solved in the second one. In the next test experiment which is expected to start in the summer of 2013, and will last about six months, a long term performance of the E-Cat HT2 will be tested. This test will be crucial for further attempts to unveil the origin of the heat phenomenon observed so far. Except these people have made absolutely no attempt to unveil the origin of the heat phenomenon they've been observing. Far from it, they keep dodging actual recommendations from their peers on how to do it. They have not substantiated their experiments with control runs, proper monitoring data, and so on, and what's more have a very bad history of refusing to cooperate with their peers because they seem to think everyone's out to get them. Of course I don't trust anything coming out of this group. Until they start taking science seriously, I cannot take them seriously as a scientist.
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May 25, 2013 22:07
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"it is a scam because we don't know how it works/it can't work". That's not how science progresses.
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I would love to see statistics for how much of what chemical is being used per produced kW or MW of solar capacity. We can't really make a good assessment of the severity of that issue without knowing both the nature and the quantity of what's being used in fabrication. I'd assume there's large quantities of "stuff" involved per unit of capacity compared to other alternatives, but that's just based loosely on cost which can vary for many reasons. There is a lot of bad stuff being used in making solar panels: http://www.bnl.gov/pv/files/pdf/art_170.pdf But there's also much worse stuff being used in enriching uranium fuel, like chlorine trifluoride, which can ignite silicate materials like sand while producing scalding-hot HF steam and copious amounts of chlorine gas. For uranium, it's not that big of a deal because the amounts used are relatively tiny and controllable.
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Jun 8, 2013 18:11
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silence_kit posted:If you actually read your own report that you posted, it concludes that the only public health issue identified with crystalline silicon solar cell manufacturing is the lead solder in the packaging of the solar cells. When you throw away the cell, the lead can get into other things. I am not super-knowledgeable about electronics packaging technology, but I have heard that they are switching away from lead-based solders. Are you addressing me or someone else? I wasn't talking about decommissioning. I was talking about trying to find the quantity of chemicals required to fabricate solar PV.
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Jun 9, 2013 17:18
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Current worst-case nuclear plant construction, riddled with cost overruns and delays, versus current best case large-scale solar construction, with heightened momentum from the flood of cheap solar panels from the Chinese market. Who do you think wins? It's still nuclear, by a huge margin.quote:Germany’s solar program will generate electricity at quadruple the cost of one of the most expensive nuclear power plants in the world, according to a new Breakthrough Institute analysis, raising serious questions about a renewable energy strategy widely heralded as a global model. The authors took a lot of flak for their findings, being accused of cherry-picking and so on. So they later responded with another article explaining how they got their numbers and why they picked the German solar program and the Finnish EPR for comparison: http://thebreakthrough.org/index.php/voices/michael-shellenberger-and-ted-nordhaus/no-solar-way-around-it/ The two articles are worth reading.
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Jun 11, 2013 16:32
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Pander posted:Gizmodo article on the benefits of using Thorium oxides to eat up all of the plutonium waste generated by nuclear plants. Nice read. I just have to correct a few things in there: quote:Luckily, thorium (Th232) is an abundant—albeit slightly radioactive—element. It's estimated to be four times as common as uranium and 500 times as much as Here's a link to their official site http://www.thorenergy.no/ Interest really ramped up after these simulations were published: http://www.hindawi.com/journals/stni/2013/867561/ I think this is really cool for several reasons. For starters, it's a fuel matrix that can be used in existing light water reactors and heavy water reactors with relatively small adjustments. It's miles ahead from uranium-based MOX fuels, in that it's much cheaper to fabricate and capable of achieving near-complete plutonium burnup without any serious increases in positive feedback, thanks to thorium-232's nicer temperament when it comes to freshly-emitted neutrons compared to U-238 which likes to undergo energetic fission in those conditions. Thorium itself is ridiculously easy to obtain. It's practically free from heavy-rare earth deposits like Monazite sands, and even without concentrated sources it can be extracted from absolute sources like igneous rock for almost nothing.
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Jul 4, 2013 01:05
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. But that's where the plutonium comes in. What Thor energy did was mix ceramic thorium oxide (ThO2) with plutonium oxide (nuclear waste) in a 90:10 ratio to create thorium-MOX (mixed-oxide). The thorium oxide acts as a matrix that holds the plutonium in place as its used up.
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Nevvy Z posted:Does this stuff have to be held to higher storage standards than the already impossible store waste we produce? U-232 has a ridiculously large fission cross-section, so it is easily destroyed in any given nuclear reactor. With thorium MOX, U-232 is created as it's being destroyed up until it reaches equilibrium at a concentration of 0.4% (http://www.princeton.edu/sgs/publications/sgs/pdf/9_1kang.pdf). If you happen to have an excess of U-233 fuel with U-232 you need to get rid of for any reason, you can just throw it in a non-thorium using system and fission it completely. That said, if you ever decide to shut down a nuclear reactor and brush U-233 fuel contaminated with U-232 under the carpet for 40 years hoping people forget about it, leaving the fuel on-site in a chemical form that evolves fluorine, then expect cleanup and disposal of the resulting mess to cost around half a billion USD: http://energy.gov/ig/downloads/audit-report-ig-0834 More detail: http://energy.gov/nepa/downloads/ea-1488-environmental-assessment-u-233-disposition-medical-isotope-production-and Nuclear does not misbehave when it's treated properly. If only states would just treat it properly.
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Jul 5, 2013 18:25
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Paper Mac posted:So, this is a scam, right? At immediate first glance I thought it was genuine, because there have been materials that can suck up a ridiculous amount of CO2 reversibly (layered double hydroxides, for instance http://pubs.acs.org/doi/abs/10.1021/ie060757k). A nanoparticulate LDH "gas" could be cheap enough and have enough surface area to completely soak up CO2, in principle. But then I read this garbage on their site: http://www.hydroinfra.com/en/solutions/what-is-hng/ quote:HNG is packed with ‘Exotic Hydrogen’ There's the bullshit about how they're somehow storing exotic matter, which is indeed a thing but not anything you can generate without a particle accelerator anyway. Also there's nothing to suggest that exotic hydrogen will neutralize CO2 or other pollutants; it would probably do something entirely different if it came into contact with another atom/molecule, like rip itself apart and leave the pollutant molecule unscathed. But pay very close attention to what HNG actually is; a mixture of hydrogen and oxygen. For some reason, hydrogen-oxygen gas mixtures are a fascinating avenue for scams (http://en.wikipedia.org/wiki/Oxyhydrogen http://www.nature.com/news/2007/070910/full/news070910-13.html), probably because practically anyone with an outlet can generate the legendary 2:1 hydrogen oxygen gas mixture purported to be an amazing fuel additive (except it really isn't) and being able to cyclically power a car because generating it takes less energy than creating it (except it doesn't, see water-car scam). Office Thug fucked around with this message at 20:04 on Aug 2, 2013 |
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Aug 2, 2013 20:00
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Anosmoman posted:Can you have a nuclear power program that enables you to build power plants but not nuclear weapons? You could have the richer states export tamper-resistant modular reactors, with these states also offering to replace the "core" with a fresh one when needed and also dealing with the spent core themselves. There's actually several advantages with this scheme, especially when it comes to breeders like thorium reactors and fast reactors, notably because many of the spent-core products would be very valuable nuclear isotopes and other products. It also guarantees fuel contracts, which is basically the only thing the US wants anyway.
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Aug 20, 2013 01:15
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France is looking to shoot itself in the foot apparently. http://www.bloomberg.com/news/2013-09-20/france-plans-carbon-tax-atomic-cap-in-27-billion-energy-shift.html quote:France will introduce a carbon levy and a law to cap nuclear-power capacity next year under plans to boost renewable generation that will cost about 20 billion euros ($27 billion) a year, according to President Francois Hollande. For $27 billion a year they could be putting up a new nuclear plant generating some 450 TWh total over its 60 year life. The problem is that unlike Germany, they don't have extremely dirty coal to fall back on if this gamble doesn't pay off. They plan to cut nuclear capacity in half with their current total nuclear capacity being 425 TWh per year. Much like the Germans, they'll do this quickly and worry about the details later because nuclear is so scary etc.. The worst part is that other states are also depending on energy exports from France, with some 50 TWh being exported from them. I wish they'd just look across the border to check out how Germany is doing with its ridiculous plan. Because it doesn't look like it's going so well over there. Office Thug fucked around with this message at 15:56 on Sep 25, 2013 |
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Sep 25, 2013 15:50
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Kafka Esq. posted:This is just political right? What are the economics of their decision? They already HAVE these plants, why cap them? I think it's because the plants are getting old and they'll be looking to retire some of the older ones around 2035 regardless. The entire fleet will reach its end-of-life point around mid 2045. But it sounds like they want to avoid re-licensing and retire them faster, with half the fleet going offline by 2026. The cap is just saying that they won't be replacing the retired plants with as many new nuclear plants. However, they've already pretty much "phased out" the construction of new nuclear plants via knee-jerk reactionary regulatory ratcheting. The ongoing cost of nuclear plants that were under construction in France magically doubled after Fukushima. More or less because they took a page out of US' book on how to "improve" nuclear safety. Their plan is obviously geared towards phasing out nuclear, and to hell with the consequences. Their alternative approach is "Spend exorbitant amounts of money every year to use renewables and use less energy", so it's hard to tell what the economics will look like. They won't get anywhere near as much bang for their buck as they would if they built another fleet of standardized nuclear plants. Heck, even with the doubled costs for their newer plants (~9 billion euros per ~45 TWh/year production with EPRs), it would be an uphill battle to go with renewables instead. They're going to invest 20 billion euros yearly to enact their plan. If they invested those 20 billion euros into building new nuclear capacity, breaking ground with 12 new plants right away, they'd only need to invest 20 billion every year over 6 years in order to completely replace their old nuclear capacity. They could stretch that over 15-20 years comfortably without needing to do any drastic refurbishing of current existing plants.
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Sep 25, 2013 20:36
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Hasters posted:That's not what I'm talking about, allow me to try again. Every human over the age of three understands "fire hot", it's almost as intrinsic to our species as using that fire to burn things is. However most adults, even those with college educations, don't really understand controlled nuclear fission; it's just not something that exists in our day to day lives. People could understand fission, fuel cycles, how waste occurs and how to make bombs (and thus strengthen nuclear designs against proliferation) with gruesome detail. And yet I am almost 100% certain their anti-nuclear poeition would not change. It's because they can't rationalize in terms of comparison. If I really wanted to educate people about nuclear, I'd first need to learn how to educate people to think critically. How can I convince people that there's a better solution, based on comparisons and relativity, when the very concept of what makes something a more desirable approach is totally alien to them?
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Sep 26, 2013 18:03
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LP97S posted:Is it still kosher to bring up the Nuclear is still cheaper than solar wrt Finland and Germany or did something definitive come out trashing it? It comes from a fairly well-established energy/environment research group, The Breakthrough Institute. It's been criticized by readers in the comment boxes (natch), but as far as I could tell with google search it hasn't been rebuked by anyone with more expertise yet. Here's the original study: http://thebreakthrough.org/index.php/programs/energy-and-climate/cost-of-german-solar-is-four-times-finnish-nuclear/ They also made a follow-up concerning criticism of that study: http://thebreakthrough.org/index.php/voices/michael-shellenberger-and-ted-nordhaus/no-solar-way-around-it/ And a follow-up on that follow-up that explains how/why nuclear scales so well: http://thebreakthrough.org/index.php/programs/energy-and-climate/nuclear-has-scaled-far-more-rapidly-than-renewables/ They've also conducted studies on nuclear vs. solar subsidies, specifically in California: http://thebreakthrough.org/index.php/programs/energy-and-climate/subsidies-for-solar-two-times-higher-than-for-nuclear-in-california/ Unfortunately, I can't quote all of these articles, but I will quote the tables from one of their most recent articles that's very relevant to the current discussion about environmental footprint and resource usage: http://thebreakthrough.org/index.php/programs/energy-and-climate/nuclear-has-one-of-the-smallest-footprints/ http://thebreakthrough.org/index.php/programs/energy-and-climate/nuclear-has-one-of-the-smallest-footprints/ posted:Land Footprint Their articles are well-sourced with information that's the most recent and accurate you can realistically find for free. Edit - The commenters on that site are pretty awesome too. One of them made a graphic illustrating land use of wind versus nuclear: http://jmkorhonen.net/2013/09/04/graphic-of-the-week-comparing-land-use-of-wind-and-nuclear-energy/ Office Thug fucked around with this message at 19:01 on Sep 28, 2013 |
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Sep 28, 2013 18:51
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GrumpyDoctor posted:I asked this a few pages ago and I'm hoping it only got missed: Does anyone have any recommendations for Fukushima cleanup news? Obviously I can just Google "Fukishima news" or something but there's a lot of stuff out there and I don't know which of it is trustworthy. This recent article isn't specific to the current problems around clean-up, but it might help you get a better feel for assessing what's accurate and what's blow out of proportions/underestimating the problem: http://www.slate.com/articles/health_and_science/science/2013/09/fukushima_disaster_new_information_about_worst_case_scenarios.html
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Sep 29, 2013 21:56
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The ICF facility? That thing that's built solely for weapons-testing that circumvents bans on live-testing? http://nnsa.energy.gov/aboutus/ourprograms/defenseprograms/stockpilestewardship/inertialconfinementfusion
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Oct 11, 2013 02:41
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