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The only people who can do it are people who already have invested billions into developing nuclear weapons technology, so I really don't see where you're going with this.
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Dec 1, 2015 16:26
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QuarkJets posted:You don't have to resort to conjecture, you can just go look at how much we spend on nuclear power R&D and solar power R&D. Let's ask the people who actually study this: the Energy Information Administration (EIA) Ok, so you agree. The idea proposed earlier that nuclear energy is some kind of black sheep and that solar energy is the darling child in terms of research funding is patently absurd. I was actually surprised that in 2013 nuclear energy was receiving more research money even though it is a super old and mature technology. I bet that if you look at the early days of nuclear & solar the disparity will be way more stark. I guess the posters in this thread are looking for any sort of excuse to use to explain away the drawbacks of their pet technology.
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Dec 1, 2015 16:41
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blowfish posted:Yes, but I suspect particularly if very applied stuff such as radiation safety and reactor design and not just development of breeders for 2050 deployment become a main focus that gets more than a token amount of funding. I question whether more applied research will do a good job of lowering the cost of nuclear energy. My understanding is that researchers don't really have a good understanding of how much things cost or how to reduce cost and this type of development work is better for companies to do. Researchers are better at proposing and working on new things, be they important to society or totally irrelevant to society. Like the DoE research emphasis on making junk solar cells but at (potentially) lower cost than silicon 5-10 years ago was totally irrelevant to the growth of solar energy. That growth was due to companies figuring out how to make silicon cells at lower cost. silence_kit fucked around with this message at 17:12 on Dec 1, 2015 |
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Dec 1, 2015 16:57
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Phayray posted:You absolutely can turn spent fuel into weapons material with the right amount of burnup. Anyone using the current style LWRs with LEU could, hypothetically, make weapons material. You could also make a dirty bomb out of spent fuel! This is like the Bush administration saying that the centrifuges Iraq wanted could be modified to enrich uranium or whatever it was they claimed. By melting them down and starting from the raw materials. If we're worried about low enriched uranium making their way into weapons then Iran has a fuckton of it in the ground to mine.
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Dec 1, 2015 17:48
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silence_kit posted:Ok, so you agree. The idea proposed earlier that nuclear energy is some kind of black sheep and that solar energy is the darling child in terms of research funding is patently absurd. A lot of that nuclear funding is for research into making old reactors safe, not for improving the technology.
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Dec 1, 2015 20:30
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Kalman posted:A lot of that nuclear funding is for research into making old reactors safe, not for improving the technology. Actually, no. The EIA numbers are discussing R&D that will increase or improve future energy supplies or reduce consumption. It isn't research into safety retrofits. That research is likely accounted for elsewhere (probably at companies or the NRC not in R&D grants). quote:The federal government has an extensive program of funding energy research and development (R&D) activities aimed at a variety of goals, such as increasing U.S. energy supplies or improving the efficiency of various energy consumption, production, transformation, and end-use technologies. R&D programs generally do not directly affect current energy consumption, production, and prices, but if successful, they could affect future consumption, production, and prices. edit: here's the 2010 roadmap for nuclear R&D from DoE, which shows that the goals are in these areas: quote:R&D OBJECTIVE 1: Develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of current reactors While some of those objects may positively impact the existing fleet, included objective 1, which is trying to keep the current fleet in operation. They're not really safety improvement focused, because the current best-practices have marginal room for improvement on safety. http://energy.gov/sites/prod/files/NuclearEnergy_Roadmap_Final.pdf Trabisnikof fucked around with this message at 21:37 on Dec 1, 2015 |
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Dec 1, 2015 21:27
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Phayray posted:I didn't say it was easy, just that it's possible, refuting ductonius' claim that "You can't turn spent fuel into weapons either". What refuting? You've done none of that. The points brought up that separating usable nuclear bomb material from spent fuel is prohibitively difficult is exactly what I was getting at. Power reactor fuel is a mixture of u-235 and u-238 and as such is garbage for producing bomb-grade materials. Garbage in, garbage out. Of all the nuclear nations none of them got their bomb plutonium from spent power reactor fuel. None of them. They all used research reactors to irradiate U-238 just enough to get a usable ratio of Pu-239 to Pu-240. Do power reactors make pu-239? Absolutely, it's just so mixed up with other crap that spent power reactor fuel is not useful for making bombs. It's so prohibitively difficult not even the United Stated ever did it. Anyone who could try would find it much easier to build a research reactor instead. ductonius fucked around with this message at 21:53 on Dec 1, 2015 |
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Dec 1, 2015 21:51
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ductonius posted:What refuting? You've done none of that. I'm not sure "research reactor" is the right term, unless it's like a Japanese "whaling research" vessel intended to research "How many whales can we catch in one week?" The Hanford plutonium production reactors weren''t useful for researching anything other than "How do we make bomb fuel as quick as we can?"
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Dec 1, 2015 22:35
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Leave it to D&D to take something completely factually true and uncontroversial (you can produce weapons plutonium from the standard LWR commercial reactor design) and turn it into a debate. It's especially funny since we were just talking about reprocessing, where you extract the usable plutonium from spent fuel. Guess what happens if you do this process with low burnup fuel, where the Pu-239/Pu-240(-242) ratios are much better? I think I've posted this before but there are projects specifically to look for unusual cycling of reactors with the express intent of catching low burnup -> plutonium production, such as the WATCHMAN project. Again, this is not the typical commercial reactor operational case, where I agree that the plutonium isotopic ratios make the plutonium extracted from this fuel unusable for weapons. Again, I understand that it's not easy and not optimal for producing weapons plutonium, but that's not the point. Of course the US didn't do it, because we didn't have to. The point is to do in secretly and a commercial reactor would provide good cover. As someone that works in the nuclear security sector, I can tell you that the very smart and Very Serious People are absolutely concerned about plutonium production in standard LWRs. Not in the US, obviously, but as the world builds more nuclear reactors this becomes a bigger concern. hobbesmaster posted:This is like the Bush administration saying that the centrifuges Iraq wanted could be modified to enrich uranium or whatever it was they claimed. I was talking about plutonium, not uranium. I agree that no one is worried about LEU (directly) ending up in weapons. Phayray fucked around with this message at 23:16 on Dec 1, 2015 |
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Dec 1, 2015 23:06
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ductonius posted:You can't turn spent fuel into weapons either, and power reactor research has precious little to do with nuclear weapons development. Nuclear weapons tech and nuclear power tech are connected by virtue of using the same chemical elements but after that nearly everything about them is different. I think that Bolow was alluding to the fact that sometimes those pots of money get mixed in interesting ways. For instance, the NIF basically exists in order to produce better nuclear weapon models, but all of their public outreach stuff is about advertising the benefits of nuclear fusion and how cool it is try and do nuclear fusion using laser confinement. And it's totally reasonable for them to do that, because their research does enhance our knowledge of nuclear fusion, which could one day have huge payoffs even if fusion via laser confinement doesn't pan out. I don't think that there's nearly as much overlap between fission power and nuclear weapons today, but in the early days of nuclear research there definitely was some overlap. silence_kit posted:Ok, so you agree. The idea proposed earlier that nuclear energy is some kind of black sheep and that solar energy is the darling child in terms of research funding is patently absurd. Yeah, I agree. My opinion is that we don't suffer from a lack of nuclear R&D funding, we suffer from a lack of deployment of modern nuclear reactors. silence_kit posted:I question whether more applied research will do a good job of lowering the cost of nuclear energy. My understanding is that researchers don't really have a good understanding of how much things cost or how to reduce cost and this type of development work is better for companies to do. Researchers are better at proposing and working on new things, be they important to society or totally irrelevant to society. I disagree with this; many R&D projects are specifically meant to reduce the cost of production-level *whatever*, and many of the projects that the DOE lists as funding priorities are aimed at or have a benefit relating to making nuclear power more affordable. And while it's true that the DOE funded junk solar cell research, they also funded a lot of the research that led to cheaper silicon cells; both of these were good things to fund.
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Dec 2, 2015 01:38
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QuarkJets posted:I disagree with this; many R&D projects are specifically meant to reduce the cost of production-level *whatever*, and many of the projects that the DOE lists as funding priorities are aimed at or have a benefit relating to making nuclear power more affordable. And while it's true that the DOE funded junk solar cell research, they also funded a lot of the research that led to cheaper silicon cells; both of these were good things to fund. I don't know if results from academic research are really what lead to the huge drop in cost of solar cells. Academics have no idea what things cost. Many of them have never worked at companies, so the way they figure out how much things cost is if the government tells them that something is too expensive or when they order one-off or custom stuff for their labs, which is not the cost of something in production. They are removed from worrying about a lot of the realities of production. I would be shocked if there were a non-negligible number of academics who did research on how to lower costs in the silicon purification & the bulk crystallization processes in the past 30-40 years. That kind of stuff (how to more efficiently run a chemical plant so the production cost is lower) is a tough subject for academics to research, since they are so far removed from that. Probably what happened is that the companies running these silicon plants were seriously squeezed on price & volume for the first time in a while, and they came up with a bunch of incremental ways to improve their process. Improvements were stuff like, figuring out how to saw the wafers from the big silicon boule without creating so much dust and wasting so much material. The processes which people use to make solar silicon were adopted from processes used to make silicon for integrated circuits, and the silicon material cost in silicon integrated circuits is dwarfed by the production cost of putting the wires and transistors on the chips and the development cost. Also, the people who design & sell chips often make pretty handsome profits on them, so probably the silicon plants were never really heavily pressured to improve their efficiencies and lower their costs until solar cells became more popular.
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Dec 2, 2015 16:09
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If the solar cells are functionally identical or very similar, then it's probably because of some process improvement at the production level. If instead there's a different type of solar cell entirely (different material, etc) that's more efficient, then that's at least partially based in academic research.
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Dec 3, 2015 05:10
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Almost everything that you have written here is wrong, and I'm beginning to think that maybe you don't know anything about how public or private research works silence_kit posted:I don't know if results from academic research are really what lead to the huge drop in cost of solar cells. Academics have no idea what things cost. Many of them have never worked at companies, so the way they figure out how much things cost is if the government tells them that something is too expensive or when they order one-off or custom stuff for their labs, which is not the cost of something in production. They are removed from worrying about a lot of the realities of production. This section of your post is completely idiotic and not worth responding to with any seriousness, but I'm bored so let's get into it. Your post starts off with a generalization about academics having no financial sense and then immediately transitions into the falsehood that many academics have had no experience in the private sector and just get told by the government whether things are too expensive to buy. This view of modern academic research is so far removed from reality that it's become clear that you actually have no experience with or knowledge of academic research, nor R&D in general in all likelihood. You probably shouldn't use an authoritative tone when posting about subjects in which you have no prior knowledge or experience And before you accuse me of just being a knee-jerk academic, I work in private R&D. For the record: private and public R&D are so deeply intertwined that there's no point in entertaining the ivory tower fantasy. The fact of the matter is that there are many academics who have worked in private R&D at some point, work or have worked with private R&D groups while pursuing academic interests, or are even working with private R&D right now as either consultants, employees, or business owners. quote:I would be shocked if there were a non-negligible number of academics who did research on how to lower costs in the silicon purification & the bulk crystallization processes in the past 30-40 years. That kind of stuff (how to more efficiently run a chemical plant so the production cost is lower) is a tough subject for academics to research, since they are so far removed from that. Probably what happened is that the companies running these silicon plants were seriously squeezed on price & volume for the first time in a while, and they came up with a bunch of incremental ways to improve their process. Improvements were stuff like, figuring out how to saw the wafers from the big silicon boule without creating so much dust and wasting so much material. Counterpoint: mass production of Penicillin was made possible by academics at Oxford working on that problem specifically. They weren't bankrolled by a pharmaceutical company tasking them to come up with such an innovation, they sought to make Penicillin mass-producible because it was a thing that they were interested in and that they believed was worth pursuing. Is it really that hard to believe that there are academics out there that are working toward a similar goal with solar power, especially when given the potentially Earth-saving ramifications of affordable green energy? That said, the purpose of research often is not to reduce the cost of a specific process, but that's sometimes what winds up happening anyway as a knock-on effect. The importance of this kind of effect cannot be emphasized enough; countless industries benefit economically every year from what might otherwise seem like commonplace academic results. quote:The processes which people use to make solar silicon were adopted from processes used to make silicon for integrated circuits, and the silicon material cost in silicon integrated circuits is dwarfed by the production cost of putting the wires and transistors on the chips and the development cost. Also, the people who design & sell chips often make pretty handsome profits on them, so probably the silicon plants were never really heavily pressured to improve their efficiencies and lower their costs until solar cells became more popular. That could be true, yes. But do you think that this is the only way that silicon panels can become cheaper? And do you really think that academic research would have no place in improving the efficiency of silicon manufacturing or usage? QuarkJets fucked around with this message at 12:58 on Dec 3, 2015 |
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Dec 3, 2015 12:55
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QuarkJets posted:Your post starts off with a generalization about academics having no financial sense and then immediately transitions into the falsehood that many academics have had no experience in the private sector and just get told by the government whether things are too expensive to buy. Whenever researchers brag about the low costs of their proposed technology or crap on other technologies for being (fundamentally) high cost, I put big asterisks on those claims. A lot of the time they are just parroting things other researchers say, and sometimes entire research communities can believe in things that are not true. Often they are ignorant of the many of the things that go into how much things cost. Many of the reasons why things cost as much as they do companies often would prefer not to talk about, so it is no wonder that researchers can often be ignorant of costs. And the trend is that younger academics are having less or no experience at companies. Many companies that used to have big research divisions are not as committed to doing research as they used to be. Many of these companies don't like to publish, because they don't want their competitors to know what they are doing. It is harder to get academic positions now then it was in the past, and these trends regarding private research are making it even harder for people to go from industry back to academia. QuarkJets posted:That said, the purpose of research often is not to reduce the cost of a specific process, but that's sometimes what winds up happening anyway as a knock-on effect. Yeah, I agree. Researchers do best when they are trying to improve the performance of something or when they are doing something new. An unintended side effect sometimes can be that it leads to lower-cost technology. They aren't really the best equipped and/or best informed to be able to work on hyper-applied projects on how to reduce the production cost of something. That's a problem that companies are better equipped to solve.
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Dec 3, 2015 17:47
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A friend of mine posted this nice breakdown of advanced reactor technologies the other day which I thought I'd share since they occasionally come up in this thread. Even as a nuclear engineer it can be hard to remember all the different designs, their history, and their benefits/drawbacks.
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Dec 3, 2015 21:01
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I don't even work in R&D and it's pretty obvious from here that R&D can have a variety of specific focuses when working on something and seeing as I've seen documentaries made about it, I know for a fact that there are private and academic teams that are working specifically on making cheaper solar panels?  "Academics don't ever know or care what things cost!" seems pretty silly to me.Speaking of, whatever happened to that solar roofing material that is like pennies per square foot to manufacture?
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Dec 3, 2015 21:56
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Boten Anna posted:
At a guess, either it has durability issues that the low cost can't outweigh, or output issues that again aren't outweighed by the low cost.
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Dec 3, 2015 22:15
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silence_kit posted:Whenever researchers brag about the low costs of their proposed technology or crap on other technologies for being (fundamentally) high cost, I put big asterisks on those claims. A lot of the time they are just parroting things other researchers say, and sometimes entire research communities can believe in things that are not true. Often they are ignorant of the many of the things that go into how much things cost. Many of the reasons why things cost as much as they do companies often would prefer not to talk about, so it is no wonder that researchers can often be ignorant of costs. Maybe you should start putting big asterisks on all of your posts. Or maybe you could start all of your posts with "I don't actually know anything about this topic, but", that would be really helpful because everything that you've written here is either wrong, conjecture, an attempt to move the goalposts, or an allusion to some specific example that you're reluctant to bring into the discussion, probably because it's contrived or anecdotal, or both. quote:Yeah, I agree. Researchers do best when they are trying to improve the performance of something or when they are doing something new. An unintended side effect sometimes can be that it leads to lower-cost technology. Or it can be the objective of a research project, like in the Penicillin example that you just ignored. quote:They aren't really the best equipped and/or best informed to be able to work on hyper-applied projects on how to reduce the production cost of something. That's a problem that companies are better equipped to solve. Only if you want to ignore those researchers who are trying to reduce the production cost of something. Christ, how are you still not getting this? Academic research is a huge and varied field, and "we're trying to reduce the cost of process X or material Y" is a common research objective in countless academic fields.
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Dec 4, 2015 00:03
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ductonius posted:What refuting? You've done none of that. I don't think you understand what you're talking about. U238, mixed with some U235, is what you put in a reactor to make plutonium, period. U235 fission provides neutrons, U238 absorbs them to make Pu239. This is how (almost) every reactor designed to produce plutonium works. There needs to be U235 mixed with the U238 unless you are using some kind of breeder reactor that uses Pu fuel you've already produced. If anything, plutonium production reactors will use higher enriched uranium with more U235 than conventional LWRs, to maximize neutron flux. The main differences between a plutonium plant and power reactor are how they handle refueling, and how long fuel spends in the reactor. Secondary differences are that a plutonium production reactor will use a moderator that minimizes neutron losses (e.g. heavy water), may use a more optimal arrangement of fuel and breeding material, and may use a different neutron spectrum. But none of these secondary issues are essential or even hugely important. The problem with using conventional electricity generating LWR designs for Pu production has nothing to do with the nature of the fuel used. The problem is that, for a variety of reasons, you need to minimize the production of plutonium isotopes other than Pu239 if you want to have a practical weapons program and practical bombs. This means, as you note, exposing the fuel to neutrons for a relatively short time before taking it out and reprocessing for the Pu, which means frequent refueling. This is absolutely possible in conventional LWR designes, its just that A.) its easily detectable and B.) not a super fast way of making plutonium, since conventional reactors aren't great at supporting frequent refueling and there will be lots of downtime. A and B put together means you might get your poo poo ruined by anyone who gives enough of a drat about what you are doing, before you make any bombs. The fact that conventional power reactors have Pu-239 "mixed up with other crap" is not important, and does not make it prohibitively difficult to separate the Pu. The "other crap" in the uranium from a power plant is pretty much the exact same crap that would be in the uranium from a plutonium plant, provided that burnup is kept low. The plutonium separation process and everything else would all be the same. The only real problem with this approach is that it is basically impossible to hide and also not terribly fast. But its not really a fundamental engineering problem, and certainly has nothing to do with U235+U238 being ~*~garbage~*~. **SIDE NOTE: It should also be noted that the importance of keeping a low Pu-240 concentration in nuclear bomb material is really overstated. It was a much bigger problem in 1950 than in 2015 (or even 1970). From purely a bomb-design standpoint, the main problems with Pu "contaminated" with Pu-240+ are the higher neutron emission rate, and higher thermal output. Too many background neutrons can make predetonation a problem, too much thermal output and the bomb may get impractically hot. Both of these effectively require you to use a fissile core that is as small as possible with as good an implosion design as possible. Of course, in a sophisticated weapon design, these are things you want to do anyway. Fusion boosting in particular--which basically all modern designs use anyway--would make an efficient fission stage possible even with pretty poo poo grade Pu. The main problem at this point would be that handling the material would be more challenging...but that's not necessarily a show stopper. With modern weapon designs, the desire for very low Pu-240 is arguably more of a cost issue than an engineering one. Long burnup -> higher Pu240 -> cheaper to produce, but higher Pu-240 -> slightly larger critical mass needed -> more Pu needed -> more expensive. At some point, there is an economic optimum and it seems to be around 6-7%. But from a purely engineering standpoint, concentrations as high as 25% could probably be made to go boom, and ~10-15% would still probably be practical for a bomb. So now instead of having to refuel every 3-4 weeks for supergrade plutonium, you can maybe refuel every few months and still be OK. This is still short enough to arouse suspicion, since normally refueling takes place on the order of once every 10-18 months, but you've closed the gap by a lot. From here there are other tricks that can be employed. Its possible to operate the reactor at a somewhat lower power, so that you can refuel on a normal schedule while maintaining a sufficiently low burnup. You could even go so far as trying to seperate the Pu239 from Pu240 using electromagnetic separation, which is not efficient, but has been done before, and could be hidden. The point is just that if there was a state with reasonably sophisticated engineering capacity, that wanted to produce plutonium for bombs from LWR power plant fuel, and wanted to do it in a clandestine way, it would in principle be possible. It would probably be easier to just forget about plutonium and enrich uranium as quickly and quietly. Then once the cat is out of the bag and you have a bomb, pursue your plutonium dreams. But the notion that such a thing is impossible or even hugely impractical from an engineering or physics standpoint is just wrong.
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Dec 4, 2015 11:16
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Optimizing axial burnup is also an option.
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Dec 4, 2015 13:34
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I recall reading somewhere (might have been an editorial) that photovoltaics are a "technology" that experiences it's own sort of Moore's Law which drives down price and drives up efficiency, while other types of energy (especially fossil fuels) do not, and are reliant on supply and demand of the fuel for the cost. Is that at all an accurate assessment? Prices have definitely gone down but I feel like comparing solar cells to microprocessors is a bit naive.
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Dec 4, 2015 23:28
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Concordat posted:I recall reading somewhere (might have been an editorial) that photovoltaics are a "technology" that experiences it's own sort of Moore's Law which drives down price and drives up efficiency, while other types of energy (especially fossil fuels) do not, and are reliant on supply and demand of the fuel for the cost. It's called Swanson's law and has roughly held so far.
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Dec 4, 2015 23:31
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Concordat posted:I recall reading somewhere (might have been an editorial) that photovoltaics are a "technology" that experiences it's own sort of Moore's Law which drives down price and drives up efficiency, while other types of energy (especially fossil fuels) do not, and are reliant on supply and demand of the fuel for the cost. From what I have read, the pinch-point in solar cell manufacturing was the availability of polysilicon. Thanks to government incentives, demand for solar increased enough that several new sources of polysilicon came on line, which then created an oversupply and drove the costs way down. It's not really a Moore's Law situation, as there is nothing to miniaturize directly. It's just a standard economy of scale as far as I can see.
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Dec 4, 2015 23:34
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Morbus posted:With modern weapon designs, the desire for very low Pu-240 is arguably more of a cost issue than an engineering one. "Modern weapon designs" are the ones that are seriously fantastically secret, or take a hell of a lot of full-scale testing to develop. Could the US or Russia build a bomb out of more than 2-3% Pu240 plutonium? Yeah, probably, but you're not duplicating Fat Man with that. The design sophistication it requires to approach a modern weapon design is something *far and beyond* the capability of simply building a nuclear weapon. Which is interesting in and of itself. Every country that has tried to develop a nuclear weapon has succeeded on its very first attempt. The US, fUSSR, England, India, Pakistan, etc. Everyone except North Korea. I wonder what their approach was.
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Dec 5, 2015 00:15
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Concordat posted:I recall reading somewhere (might have been an editorial) that photovoltaics are a "technology" that experiences it's own sort of Moore's Law which drives down price and drives up efficiency, while other types of energy (especially fossil fuels) do not, and are reliant on supply and demand of the fuel for the cost. Whoever told you that is probably a technophilia idiot. Photovoltaics are subject to the same supply and demand forces as everything else, but instead of oil extraction and refinement efficiency it's subject to the efficiency of panel construction and deployment.
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Dec 5, 2015 00:16
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Phanatic posted:Which is interesting in and of itself. Every country that has tried to develop a nuclear weapon has succeeded on its very first attempt. The US, fUSSR, England, India, Pakistan, etc. Everyone except North Korea. I wonder what their approach was. Would anyone know about a failure? What constitutes an 'attempt'?
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Dec 5, 2015 00:18
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Tunicate posted:Would anyone know about a failure? He's referring to fizzles versus successful tests, not programs as a whole. It's pretty easy to detect a failed weapons test, the USAF has aircraft and satellites monitoring constantly. Some goon actually created an ask/tell thread about how that detection worked... It uh did not end well for him.
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Dec 5, 2015 00:34
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What went wrong? Was he military and gave away super secrets?
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Dec 5, 2015 00:38
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Tunicate posted:Would anyone know about a failure? Of sufficient magnitude? Definitely. If you do it above ground, there's an observable thermal signature. If you do it below ground, there's an observable seismic signature. quote:What constitutes an 'attempt'? ...trying to set off a nuclear bomb. I mean, if you press the button and a wire burns through and it doesn't go off *at all*, yeah, we wouldn't notice that. But if you're talking about a yield that's even in the tens to hundreds of tons of TNT equivalent, we're going to notice that. I mean, this is one of the first uses of the fast Fourier transform, to tell Soviet weapons tests apart from natural seismic activity. And if your first bomb is *that* small, then that's a fizzle, because actually designing a nuclear weapon of that small a yield is, again, the sort of thing that takes a dedicates R&D program and iterated testing to figure out, nobody's doing that as their first test article.
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Dec 5, 2015 00:40
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Concordat posted:I recall reading somewhere (might have been an editorial) that photovoltaics are a "technology" that experiences it's own sort of Moore's Law which drives down price and drives up efficiency, while other types of energy (especially fossil fuels) do not, and are reliant on supply and demand of the fuel for the cost. In computer chips, it was recognized early on that there was a lot of room for improvement in functionality, many orders of magnitude improvement. In solar cells, in the early 60's (I got it wrong earlier in the thread when I said 50's). they figured out theoretically that there was only room for a little over 2x improvement over the state of the art result in efficiency for the standard design (unconcentrated single junction). So, solar cells and computer chips are very different. That solar cell efficiency limit can be beaten in practice by using a different scheme than the standard design--these cells are called multijunction or sometimes called tandem solar cells. They are often used on satellites. A lot of people have also come up with schemes involving unusual optical physics of materials which are supposed to do better than the standard design, but these schemes place a higher demand on the optical quality of materials than the previous two types of designs and realization of those types of cells don't come anywhere close to their limit efficiencies. It's not good enough for solar cell materials to be able to absorb light--otherwise black paint would be an ideal solar cell material--good solar cell materials absorb light and do a good job of storing the incident optical energy as electrical energy, building up tremendous amounts of excited-state electrons, which can then be extracted out of the terminals of the solar cell as electricity. In poor materials for solar cells, the excited-state electrons get immediately converted into waste heat and cannot be converted into electricity. This is what I mean when I talked about the schemes exploiting unusual optical physics' sensitivity to optical quality--even the best solar cell materials to some extent convert stored electrical energy to waste heat and in order for those schemes to work they demand perfection in this aspect. silence_kit fucked around with this message at 03:14 on Dec 5, 2015 |
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Dec 5, 2015 01:32
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OPEC comitted ritual suicide Friday. The economies of Russia and Venezuela offered in appeasement to the angry Gods of oil. Bloomberg posted:OPEC abandoned all pretense this week of acting as a cartel. It’s now every member for itself. Given the current Sunni-Shia proxy-war in Syria it's unlikely the Saudis are going to do anything that could be helpful to Iran or Russia - and no one can really afford to do it without them. American shale and maybe some oil sands may go offline but they have proven inexplicably resilient so who knows how long it will take. Incidentally current oil prices are buoyed by China building up its strategic oil reserves which will continue and accelerate through 2016 albeit not enough to offset Irans return to market. Exciting times ahead for SUVs.
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Dec 5, 2015 04:31
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This is going to be awesome for Alberta/Canada they/we deserves it. Useless failed petro state.
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Dec 5, 2015 05:01
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Anosmoman posted:OPEC comitted ritual suicide Friday. The economies of Russia and Venezuela offered in appeasement to the angry Gods of oil. Isn't shale one of those things where it takes a lot of capital to start but the operation costs aren't terrible? That might explain how it keeps holding on through several price drops (because you might still be profitable, you just wouldn't be as profitable as a regular oil rig)
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Dec 5, 2015 05:28
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QuarkJets posted:Isn't shale one of those things where it takes a lot of capital to start but the operation costs aren't terrible? That might explain how it keeps holding on through several price drops (because you might still be profitable, you just wouldn't be as profitable as a regular oil rig) The other thing is that you don't get much yield per well, so you need to set up a whole bunch of them to get a lot of volume. I believe the current wells are fine but new ones aren't really being pursued, which is an issue.
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Dec 5, 2015 05:36
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Phanatic posted:"Modern weapon designs" are the ones that are seriously fantastically secret, or take a hell of a lot of full-scale testing to develop. Could the US or Russia build a bomb out of more than 2-3% Pu240 plutonium? Yeah, probably, but you're not duplicating Fat Man with that. The design sophistication it requires to approach a modern weapon design is something *far and beyond* the capability of simply building a nuclear weapon. If we restrict ourselves to the kind of "modern" design features that would make a bomb out of low-grade plutonium (say >=10% Pu240) feasible, then by far the most important is fusion boosting. Any working implosion design creates pressures of several million atmospheres, and disassembly times are on the order of 1 microsecond; looking up the triple product curve for D-T, fusion burn would require a temperature of ~10^7K, which is easily achieved even in a fizzle (say, ~100 ton yield). At that point, even gram quantities of D-T fuel will generate enough very fast neutrons to ensure a rapid and efficient fissioning of the core. And since even a "weak" fission burn is enough to initiate the fusion boosting, the weapon is immune to predetonation, even if the background neutron emission rate is high. With fusion boosting, it is relatively straightforward to get an efficient bomb from whatever amount of fissile material you use, regardless of Pu-240 content. Large fissile cores are not so feasible with low grade Pu, since the heating is much higher than from weapons grade (~15W/kg for the shittiest reactor grade Pu, vs ~4W/kg for 6% grade Pu). But even then the thermal output of a 6kg mass would be only 90W, which is manageable. It is absolutely reasonable that a fusion boosted weapon, using 6kg of low grade Pu, and a not-so-advanced implosion design, could achieve a yield of at least 20kT (i.e. same as Fat Man); quite possibly it could be as high as 40kT. And this would not require any engineering effort substantially beyond what went into the very first atomic weapons. If such a weapon were incorporated as the primary in a crude, non-staged, early 1950's style thermonuclear weapon (e.g. Li6-D blanket around the primary, with U-238 external tamper), yields approaching 50-100kT would be doable. I'll say again: the main reason why true reactor grade Pu is undesirable is because of having to manage radiation exposure, and because it generally does not make economic sense if you are an established and known weapon state. At some point, the cost savings from using longer burnup are eroded by the fact that slightly more plutonium is required for a given yield (since even numbered Pu isotopes are less fissile than odd numbered ones). If a weapon seeking state has LWRs, and wants to secretly develop a nuclear weapon, then using reactor grade plutonium extracted clandestinely or otherwise from spent fuel is a viable route, especially if the goal is simply to demonstrate a weapon to get their foot in the door of the nuclear club, after which they can move on to big boy plutonium. Interestingly, the US actually conducted a test in 1962 using a bomb with "reactor grade Pu". There is some controversy over what exactly this means, since according to the definitions in use at the time, reactor grade could mean anything above 7%. In my opinion, there are compelling reasons to believe it was in the range of at least 15% to not more than 23%, but there is no way to be sure. The yield was "under 20kT". Presumably if it were under 15 or 10kT they would have just said that but who knows. If you are interested I recommend looking it up.
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Dec 5, 2015 11:12
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QuarkJets posted:Isn't shale one of those things where it takes a lot of capital to start but the operation costs aren't terrible? That might explain how it keeps holding on through several price drops (because you might still be profitable, you just wouldn't be as profitable as a regular oil rig) It's less operating costs and more that the decline curve for shale is exponential. The wells typically pay for themselves within a year or two (at high commodity prices) and within 5-7 years, it is mostly tapped (excluding further recovery attempts). This means that companies can put wells with short term outlook on commodity prices. Also, the barriers to entry are relatively low compared to offshore.
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Dec 5, 2015 19:40
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The actual operating costs are probably a shitload lower too.
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Dec 5, 2015 22:21
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I guess it depends on what you mean by operating costs and I see that I already mixed it up from the orignal question. I think of operating costs as AFE (cost to drill, complete, and initial production costs) plus LOE (continued investment into an already producing well. I think the question is about LOE, which is going to be pretty much the same per well unless I am missing something ?
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Dec 5, 2015 22:30
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Concordat posted:I recall reading somewhere (might have been an editorial) that photovoltaics are a "technology" that experiences it's own sort of Moore's Law which drives down price and drives up efficiency, while other types of energy (especially fossil fuels) do not, and are reliant on supply and demand of the fuel for the cost. Solar is obviously a much newer technology than fossil fuels and newer technologies generally have a lot more room to improve in cost effectiveness than older, much more mature ones do. Power electronics have also gotten much cheaper and more efficient over time as well which helps with the costs of solar installation as well, the only thing that is still very costly and challenging is the issue of storage. This is why it really angers me when right-wingers will compare solar and wind directly to coal or natural gas as if they're equally mature technologies that can be compared directly against each other in cost. Either these people are really stupid or they're being intellectually dishonest.
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Dec 6, 2015 18:00
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MaxxBot posted:Solar is obviously a much newer technology than fossil fuels and newer technologies generally have a lot more room to improve in cost effectiveness than older, much more mature ones do. Power electronics have also gotten much cheaper and more efficient over time as well which helps with the costs of solar installation as well, the only thing that is still very costly and challenging is the issue of storage. I don't think that it's intellectual dishonesty to compare the actual costs of things that you can buy and use right now.
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Dec 6, 2015 20:20
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