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^^^^^ Thanks for the info, GulMadred, and thank you for saving me from terminal boredom  As for risk estimation: just so we're on the same page here, let me quote the relevant part from the book: quote:A more reasonable goal is to reduce the risk of leakage to 0.1%–that is, to one chance in a thousand. Because the radioactivity is only 1000 times worse than that of the uranium we removed from the ground, the net risk (probability multiplied by danger) is 1000 x 0.001 = 1–that is, basically the same as the risk if we hadn't mined the uranium in the first place. Gimby posted:Thing is, this is already covered to some extent. Remember that link I posted about natural reactors? Water flowing through fractured matrix is essentially the worst possible case for leaching. Vitrified waste sealed in stainless steel containers sealed in impervious clay in a bone-dry salt dome is a much more secure option. Leaching into groundwater isn't a threat to properly stored waste. Also, the total amount of waste is small and dense, so you don't need huge wastelands, the facilities can be really very small.  Or what political and social motivations, for that matter.Gimby posted:The severity times probability measure is the standard one used in pretty much all forms of risk assessment, not just in the nuclear field. Your concerns about simplicity are covered by better estimates of both severity and probablility, and being someone who has done work on this kind of calculation, these estimates certainly do take into account correlation between different factors. Creation of a saftey case is not a simple process by any strech of the imagination.
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Apr 4, 2013 13:37
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It is rather terrible that the people evaluating those sites are not considering the possibility of unicorns suddenly appearing and breaking open all of the containment vessels with their magical horns. It's not as simple as multiplying too numbers, yes, but that's because the numbers involved have to be researched and evaluated first (And there's an entire discipline for such things), but just because you're bad at math doesn't mean that the method is flawed. The Yucca Mountain facility faced a similar problem. Every time the people involved with it would update their projections of the likely and unlikely future of the facility, the NIMBY crowd would demand another couple of thousands of years of prediction. And surprisingly enough, they eventually raised the number high enough that we can't predict, therefore it was unsafe!
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Apr 4, 2013 14:44
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And anyway, in a thousand years, either we have the technology to hurl that things in the sun easily or we're extinct.
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Apr 4, 2013 15:07
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CombatInformatiker posted:As for risk estimation: just so we're on the same page here, let me quote the relevant part from the book: You're either not understanding risk analysis or you're making an incomplete argument. If Event A is 1,000 times worse than Event B, but Event A is also 1,000 times less likely to occur than Event B, then the risk is equal. Thus, assuming it is correct that mined uranium presents 1,000 times more danger, then that analysis is correct. Now, I haven't read the book. The "1,000 times worse" number isn't something you can necessarily take at face value, and he would need to justify its use in the passages upstream of that, but you're acting concerned about his multiplication rather than his use of that figure. For example, I don't think I would use "number of deaths" as my severity estimate, because the real impact of deaths is not linear. Like if a leakage event caused 1,000 people to die with 0.1% probability, but leaving it in the ground causes 1 person to die with 100% probability. That might be what you're trying to say, but... you should have said it, then. BRAKE FOR MOOSE fucked around with this message at 15:25 on Apr 4, 2013 |
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Apr 4, 2013 15:18
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He's worried in that the average remains the same, but the worst case get worse. I couldn't say why, though. It's not like the worst case is permanent land destruction or planet blowoff.
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Apr 4, 2013 15:24
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It still bothers me that this thread's title is misspelled.
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Apr 4, 2013 17:06
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hey so is anyone following the "polywell" thing that got funding from the stimulus package? that ever get anywhere?
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Apr 5, 2013 00:30
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It got renewed funding? That's fantastic. I don't know how Bussard himself is doing, but the polywell is a great design and I really hope it works out. When did you hear about it getting stimulus funding?
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Apr 5, 2013 00:32
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CombatInformatiker posted:Well, that's what I've been saying: it's not as simple as just multiplying two numbers. I didn't say that it's impossible to estimate the risk for a given storage method. But it is as simple as that, that's what Gimby is saying. You multiply probability of occurrence by the severity of occurrence. That is exactly what is going on in the book. If we don't mine the uranium at all, then you still have a bunch of uranium in the ground, so the two scenarios that we're comparing are mining and using the uranium vs not mining the uranium at all. Probability of raw uranium being radioactive = 100% Normalized units of radioactivity = 1 Risk = 1*1 = 1 Probability of radioactive waste container leaking = 0.1% Normalized units of radioactivity of leaking container = 1000 Risk = 1000*0.001 = 1 This means that the risk incurred by not mining at all is equal to the risk incurred by using the uranium and then containing the 1000x more radioactive waste products in barrels that only have a 0.1% probability of leaking. There is nothing wrong with this technique. The only criticsm that can be levied would be directed at the accuracy or relevance of the respective numbers, which is not what you were doing originally when you dismissed the book.
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Apr 5, 2013 03:05
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QuarkJets posted:But it is as simple as that, that's what Gimby is saying. You multiply probability of occurrence by the severity of occurrence. That is exactly what is going on in the book. If we don't mine the uranium at all, then you still have a bunch of uranium in the ground, so the two scenarios that we're comparing are mining and using the uranium vs not mining the uranium at all. Yeah, this is the standard method of risk analysis anywhere. Where do folks think insurance rates come from?
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Apr 5, 2013 03:39
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muike posted:It got renewed funding? That's fantastic. I don't know how Bussard himself is doing, but the polywell is a great design and I really hope it works out. When did you hear about it getting stimulus funding? I dunno, its been years, probably some blog or forum. Also, Dr. Bussard passed.
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Apr 5, 2013 03:50
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That sucks, I probably should've known that. Are you talking about the Navy funding to EMC2 or whatever the group's name was? There hasn't been a whole lot of movement since 2012 as far as I know, but it's still progressing. No major breakthroughs. Honestly, I don't know if the material engineering is there for it, or if they can afford everything they need. I'll do some reading up on it again, I guess. fake edit: the polywell has its own internet forum, that's amazing
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Apr 5, 2013 03:55
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Funding for EMC2's Polywell research continues. Last I checked each successively larger prototype produces more output, scaling up in efficiency according to Dr. Bussard's calculations. What's more, Lockheed Martin's Skunkworks has gotten into the fusion game, claiming they can have a compact fusion device producing net power within 5 years. People on the Polywell board suspect it's a Polywell-like device. People on the project have IEC backgrounds (inertial electrostatic confinement, Polywell's confinement scheme) It'll be cylindrically shaped and Bussard himself stayed such a configuration would work. http://www.talk-polywell.org/bb/viewtopic.php?f=10&t=4273 I'm pretty excited about the prospect. LM's involvement adds legitimacy to IEC fusion.
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Apr 5, 2013 19:27
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That's pretty interesting. I'm also hoping someone will try applying transformation optics theory to the design of IEC reactors to improve the magnets.
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Apr 5, 2013 19:32
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With regards to environmental impact: Uranium mining totally fucks up the landscape - however, mining for building sufficient renewable power to make a dent in the worldwide energy budget will be several times more damaging. Protip: "high energy density" vs. "we need to mine enough poo poo to cover several % of the land area and store all that energy on top of that" is key here. There's also some rough estimates on the amount of resources and land required for different energy scenarios on this blog - see the TCASE 4 article on the page I linked (written by a climate change prof from Adelaide). The main takeaway:  In order to have 100% CO2-free energy by 2050(including replacement of oil etc.), we'd require about twenty loving percent of the world steel production be used for solar thermal/wind and cover one to several percent of the world's land area (the nuke estimates in the graph are based on AP-1000s). Using a wider variety of renewable energy sources would just shift this mess around. Investing in nuclear reactors suddenly looks like a good idea  The blog also examines the S-PRISM/IFR (Integral Fast Reactor) in [url= [url]http://bravenewclimate.com/2010/02/16/ifr-fad-3a/]more detail[/url] - a research reactor using the relevant technology had been built in the 1970s, by the way. They also make the  ATOMZ crowd look even dumber than usual by producing waste that only needs to be stored for a couple of centuries and being able to burn existing waste instead of fresh uranium to boot (we'd need to invest in new reprocessing facilities, though).e: fixed link, image e2: outdated numbers for steel production, confused numbers suck my woke dick fucked around with this message at 10:34 on Apr 9, 2013 |
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Apr 9, 2013 10:07
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I CANNOT EJACULATE WITHOUT SEEING NATIVE AMERICANS BRUTALISED!
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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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I'm taking a tour of a $30 million biomass generator today, pretty excited to see how it works!  If anybody wants a specific question asked about biomass, let me know.
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Apr 10, 2013 17:28
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Just checking back in to say it was a pretty interesting tour! Apparently they are trying to use the syngas that is the byproduct of the biomass heat generation to run the generator for the co-gen. There have been lots of problems with the syngas production, but it's mostly a proof-of-concept project, so they don't mind the hiccups along the way. They might switch to running the generator off of biomethane in the future to get higher uptime, but either way, cogeneration is the way of the future.
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Apr 11, 2013 18:48
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http://www.independentaustralia.net/2013/business/renewables-can-do-24-hour-baseload-anywhere-anytime/quote:THE FUTURE of civilisation and much biodiversity hangs to a large degree on whether we can replace fossil fuels — coal, oil and gas — with clean, safe and affordable energy within several decades. The good news is that renewable energy technologies and energy efficiency measures have advanced with extraordinary speed over the past decade.
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Apr 15, 2013 03:41
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Frogmanv2 posted:http://www.independentaustralia.net/2013/business/renewables-can-do-24-hour-baseload-anywhere-anytime/
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Apr 15, 2013 05:38
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Rent-A-Cop posted:Gotta love an article that calls nuclear power "unsafe, expensive, [and] polluting" but handwaves away hydropower like drowning a few hundred square kilometers ain't no thang. It still relies on fossil fuels. quote:That’s when the peak-load power stations, that is, hydro and gas turbines, make vital contributions by filling gaps in wind and solar generation.
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Apr 15, 2013 05:49
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Rent-A-Cop posted:Gotta love an article that calls nuclear power "unsafe, expensive, [and] polluting" but handwaves away hydropower like drowning a few hundred square kilometers ain't no thang. While I agree its a bit biased, the plan calls for the usage of existing hydro power sources, not creating any new ones. karthun posted:It still relies on fossil fuels. quote:and the small remainder supplied by existing hydro and gas turbines burning renewable gases or liquids. Almost. You almost got it right.
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Apr 15, 2013 05:59
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Rent-A-Cop posted:Gotta love an article that calls nuclear power "unsafe, expensive, [and] polluting" but handwaves away hydropower like drowning a few hundred square kilometers ain't no thang. Yeah even I at my most nuclear-evasive wouldn't want to replace nuclear with hydro power, but the plan specifically refers to existing hydro power schemes and not building new ones. karthun posted:It still relies on fossil fuels. Gas can be generated from solar power and CO2 feedstock - it's net carbon neutral. There's a difference between organic and fossil fuels.
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Apr 15, 2013 06:01
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Waaaah the Christians are out to get me
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Frogmanv2 posted:While I agree its a bit biased, the plan calls for the usage of existing hydro power sources, not creating any new ones. Quantum Mechanic posted:Yeah even I at my most nuclear-evasive wouldn't want to replace nuclear with hydro power, but the plan specifically refers to existing hydro power schemes and not building new ones. It COULD be, but that doesn't mean that it will be. It is like the supposed hydrogen economy during the 05ish. We COULD generate hydrogen by using wind and solar to electrolyze water, or we could just crack methane using steam reformation. But it wouldn't be done that way. People do know that the hydrogen economy was a push for greater fossil fuel usage right? Same with bioproduction of methane, Yes methane COULD be produced with organic waste, but it would be put up against current fracking technology. I doubt that it would be successful at taking us off of fossil fuels, much like hydrogen.
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Apr 15, 2013 06:35
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karthun posted:It COULD be, but that doesn't mean that it will be. What you posted was "it still relies on fossil fuels." It doesn't rely on them, it simply still has the possibility of using them. That's not the same thing. Stop moving the loving goalposts.
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Apr 15, 2013 07:17
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Quantum Mechanic posted:What you posted was "it still relies on fossil fuels." It doesn't rely on them, it simply still has the possibility of using them. That's not the same thing. Stop moving the loving goalposts. How about I am skeptical that it would not rely on fossil fuels for the same reason why I am skeptical that the hydrogen economy would not rely on fossil fuels.
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Apr 15, 2013 07:21
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karthun posted:How about I am skeptical that it would not rely on fossil fuels for the same reason why I am skeptical that the hydrogen economy would not rely on fossil fuels. Because the move to renewable energy is change in energy GENERATION, where the hydrogen economy was a change in energy DELIVERY. They're two different paradigms. Nothing about hydrogen inherently states that it is generated through zero-carbon means, where zero-carbon generation is the fundamental purpose of a renewable economy. Why would you possibly judge the behaviour of generators within a system that was never explicitly designed to reduce fossil fuel consumption, merely the efficiency of consumption, with one where that is the entire purpose?
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Apr 15, 2013 07:35
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Quantum Mechanic posted:Because the move to renewable energy is change in energy GENERATION, where the hydrogen economy was a change in energy DELIVERY. They're two different paradigms. Nothing about hydrogen inherently states that it is generated through zero-carbon means, where zero-carbon generation is the fundamental purpose of a renewable economy. That wasn't John Bockris's plan/dream. He wanted to implement a solar hydrogen energy cycle. You are right that the hydrogen itself is just a carrier of energy, just like methane. Bockris wanted massive solar arrays and nuclear reactors to produce hydrogen gas. This hydrogen gas would then be used to take us off of all fossil fuels. The main problem with the hydrogen economy plan is that it still has to compete against natural gas for for hydrogen production. This is the main flaw of the hydrogen economy, I am skeptical that the solar-hydrogen energy cycle will be able to compete against the natural gas-hydrogen cycle. This exact same flaw exists in for biomethane, it needs to compete against fracked natural gas. Don't get me wrong, I would love for biomethane production to be competitive against fracked natural gas. It is important to note that we need to differentiate between capturing waste biogas off of landfills and sewage with building the actual infrastructure needed to produce orders of magnitude more biogas.
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Apr 15, 2013 08:38
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karthun posted:This exact same flaw exists in for biomethane, it needs to compete against fracked natural gas. Why? Because its cheaper?
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Apr 15, 2013 08:45
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Mined fossil fuels being cheaper than carbon-neutral synthesized fuels is a problem that can be addressed through the tax system (preferably "sin taxes" on fossil fuels rather than subsidies on carbon-neutral fuels, but either could accomplish the end of making the use of neutral fuels the cheaper option).
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Apr 15, 2013 08:49
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karthun posted:I am skeptical that the solar-hydrogen energy cycle will be able to compete against the natural gas-hydrogen cycle. Then it's a good thing nobody was proposing a solar-hydrogen energy cycle  karthun posted:This exact same flaw exists in for biomethane, it needs to compete against fracked natural gas. Don't get me wrong, I would love for biomethane production to be competitive against fracked natural gas. It is important to note that we need to differentiate between capturing waste biogas off of landfills and sewage with building the actual infrastructure needed to produce orders of magnitude more biogas. a) the amount of gas needed for peaking against renewables is not large, and could certainly not maintain a massive fracking industry b) carbon pricing is an integral part of a renewable energy program You've kind of gone off the rails here.
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Apr 15, 2013 09:30
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Quantum Mechanic posted:Then it's a good thing nobody was proposing a solar-hydrogen energy cycle Solar-hydrogen energy cycle is an example of where people wanted to implement hydrogen generation as part of the hydrogen economy. quote:a) the amount of gas needed for peaking against renewables is not large, and could certainly not maintain a massive fracking industry The concern raised in the article was of calm winter evenings after overcast days. We would require heavy use of peakers to not only keep the lights on but also heat everyone homes during a good chuck of winter. That is unless you want to continue to use natural gas furnaces for heating. As a reminder it is April 15th and we are still dealing with snow and sub-freezing temps.
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Apr 15, 2013 10:38
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karthun posted:Solar-hydrogen energy cycle is an example of where people wanted to implement hydrogen generation as part of the hydrogen economy. But not to the express purpose of going zero-carbon. karthun posted:The concern raised in the article was of calm winter evenings after overcast days. We would require heavy use of peakers to not only keep the lights on but also heat everyone homes during a good chuck of winter. That is unless you want to continue to use natural gas furnaces for heating. As a reminder it is April 15th and we are still dealing with snow and sub-freezing temps. Please find me an area of Australia currently experiencing sub-freezing temperatures and snow. Please find me an area of Australia outside of Thredbo and the Perisher Valley where snow and sub-zero temperatures are anything more than an oddity. Even through an Australian winter solar thermal can provide the majority of consumed power. Solar power doesn't shut down when it's cold, it just outputs less energy.
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Apr 15, 2013 11:04
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Hmm the snowy mountains perhaps?
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Apr 15, 2013 11:23
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Aureon posted:Saint loving god, are we still talking about freaking fukushima? Plus the death toll from radiation from the Fukushima nuclear plants looks suspiciously like it's, um, zero. A couple of people at the plant did get hit by falling objects caused by the earthquake and die, though, so maybe we should avoid power generation technologies based on using tall things?
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Apr 15, 2013 13:05
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Quantum Mechanic posted:But not to the express purpose of going zero-carbon. I am not the one saying that "Renewables can do 24-hour base load anywhere, anytime" while repeating lies about the one technology that should be used along side with massive renewable deployment.
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Apr 15, 2013 16:29
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blowfish posted:Uranium mining totally fucks up the landscape - however, mining for building sufficient renewable power to make a dent in the worldwide energy budget will be several times more damaging. The thing is the scales are totally different. What you dig out of one uranium mine site could run the whole world for years, whereas you're going to need a lot more solar panels or hydro dams to generate equivalent output.
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Apr 15, 2013 16:49
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Paul MaudDib posted:The thing is the scales are totally different. What you dig out of one uranium mine site could run the whole world for years, whereas you're going to need a lot more solar panels or hydro dams to generate equivalent output. There's also the ocean extraction method. Does anyone know what the latest prices for that are?
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Apr 15, 2013 19:24
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QuarkJets posted:But it is as simple as that, that's what Gimby is saying. You multiply probability of occurrence by the severity of occurrence. That is exactly what is going on in the book. If we don't mine the uranium at all, then you still have a bunch of uranium in the ground, so the two scenarios that we're comparing are mining and using the uranium vs not mining the uranium at all. There is something wrong with this technique, which is that it inheretly assumes that the expected values fully characterize the distribution - as Bernoulli. Don't get me wrong, if you'd actually be able to find out the "probability" of of leakage then you could calculate which leakage you'd expect, and this could be equal to a certain outcome such as mining. But you can't, because it does not exist as a binary case. And because of this, nothing you said is essentially applicable to reality. It would be very easy to assume a distribution of leakage with the same "risk" (ie. expected value), yet a much higher probability to leak a lot of material. It would have the same expected leakage. This could be characterized as more risky and in fact this is very often the case out there. Which is also why risk is not equal to expected value, which is a valid criticism for any of these arguments. It is a fake argument and it is meaningless to reality. And any numbers derived on the basis of such a model would be misleading. Solkanar512 posted:Yeah, this is the standard method of risk analysis anywhere. Where do folks think insurance rates come from? Ya... no. This is exactly the reason why your insurance rate is not based only on this. Edit: Not that enough entities have made this mistake before of course. But it is not correct to describe reality this way, especially for risk analysis.
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Apr 15, 2013 20:03
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Kiwi Ghost Chips posted:There's also the ocean extraction method. Does anyone know what the latest prices for that are? I vaguely remember the last time this came up in discussion that someone had pegged it at ~$300/unit for salt water extraction which was ~double-ish of what the market price was. I'm at work right now so can't Google too much but I saw a few articles talking about how Oak Ridge came up with some new method of extraction that would bring the current cost down so if I am even close to accurate you can use that as a rough baseline. Maybe on my break I'll find something or I'll just go back to lurking.
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Apr 15, 2013 20:59
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