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I think it allows you reuse fuel that's already been through a reactor once. I'm not sure of the details. It results in weapons grade material. I believe Carter stopped it for that reason.
I'd be happy to submit to IAEA inspections if we were reprocessing it. It seems stupid not to do it.
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UK ministers propose to bring online one new wind-turbine per day to meet the EuropeanUnion carbon emissions cap. The article mentions 12years for project completion, but realisticly the rate would have to be continued indefinitely (in the manner of road-building and road-repairs) as increasing global demand in comparison to global supply makes higher fossil-fuel prices inevitable.
quote:
quote:Interestingly, a LOT more than 100% of YuccaMountain's planned total storage capacity will be needed to store wastes already being held in US temporary storage facilities.
Is this true even if the fuel reprocessing is pursued in the future?
While misleading due to what it doesn't say, this wiki on mixed oxides as reactor fuel is a decent enough start. Misleading because even after maximum recycling, nontransuranics and high-gamma emitters (such as americium) will make up about half* the volume of the original/non-recycled waste. Or more correctly, ceramic rods/pellets cast to (somewhat safely) contain that waste will take up about half the storage volume. And misleading in the same sense that the IEA report projects "...conventional uranium stock...based on the 2004 nuclear electricity generation rate...is sufficient for 85 years..." into " ...over 2500 years..." when fast-breeder reactors safe enough for commercial use is nearly as far off into the future as commercial fusion, and is only a little less hypothetical.
* Guesstimate based upon expectable radioactive waste produced by a deuterium-tritium fusion reactor generating as much power as a fission reactor. Irrespective of source, having neutrons flying around produces a lot of high-level radioactive waste.
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Dubya&Gang "...refused to accept the Environmental Protection Agency’s conclusion that greenhouse gases are pollutants that must be controlled, telling agency officials that an e-mail message containing the document would not be opened."
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Dubya&Gang "...refused to accept the Environmental Protection Agency’s conclusion that greenhouse gases are pollutants that must be controlled, telling agency officials that an e-mail message containing the document would not be opened.
Not surprising really. Such actions to maintain deliberate ignorance in order to feel free push a malicious agenda has been the modus operandi of the DubyaAdministration.
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Also, it isn't just that we stopped....the new breed of reactors will be able to use even MORE of the spent fuel than the current ones, and the new processes do not result in weapons grade materials.
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...I thought all plutonium was weapons grade, there just isn't enough of it in a reactor to be worthwhile?
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quote:Originally posted by AvidReader: ...I thought all plutonium was weapons grade, there just isn't enough of it in a reactor to be worthwhile?
No, To be weapons grade, plutonium like uranium has to be in high concentration. There is plenty of plutonium in spent reactor fuel, it is just way too low in concentration to be usable.
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So the problem is one of seperating the atoms in the spent fuel? Keeping the plutonium away from the cobalt or something?
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quote:Originally posted by AvidReader: So the problem is one of seperating the atoms in the spent fuel? Keeping the plutonium away from the cobalt or something?
More or less although it is not particularly about the Cobalt. In order to be weapons grade all fissionable elements have to be very high purity, otherwise the chain reaction won't lead to an explosion.
Its easier to enrich Plutonium from spent reactor fuel than to enrich Uranium because you can separate using the differences in chemical reactivity rather than solely by mass. But easier doesn't mean easy.
After separating the Plutonium from everything else in the reactor fuel, things get somewhat more complicated. Although all the common isotopes of Plutonium are technically fissile, they can't all be used to make a high yield bomb. The plutonium in typical spent reactor fuel has too high a proportion of 240^Pu to make a stable high yield bomb. You could probably make a dirty bomb without doing isotopic enrichment but not a high yield thermo-nuclear device. Weapons grade plutonium is generally made in special reactors designed to reduce formation of 240^Pu and not in commercial power reactors.
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Something weird about the link: it'll relink to a page that says you have already watched it. But if you BACK out of that page, the lecture will begin. The first time I tried it, I had to reENTER the address bar after BACKing.
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Ya can cover a cake with a cup of icing or with a gallon of icing, and the extent of coverage is the same. It's the volume that counts. A 50% increase in 2008's maximum Arctic winter sea ice thickness would still be considerably thinner than the numbers derived from direct sonar measurements made by USNavy submarines back in the early 1970s.
Interesting USGeologicalService animated graphic about vegetation changes in GlacierNationalPark from 1850 to 2100. The glaciers disappear around 2030.
quote:Originally posted by aspectre: Ya can cover a cake with a cup of icing or with a gallon of icing, and the extent of coverage is the same. It's the volume that counts. A 50% increase in 2008's maximum Arctic winter sea ice thickness would still be considerably thinner than the numbers derived from direct sonar measurements made by USNavy submarines back in the early 1970s.
Completely true but the extent of sea ice coverage is still the relevant number if you are concerned about the earth's albedo and the radiative heat balance.
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Map and chart of Arctic sea ice thickness as a derivation from age estimates. "Indications of winter ice thickness...reveal that the ice is thinner than average, suggesting that it is more susceptible to melting away during the coming summer...First-year ice in particular is thinner and more prone to melting away than thicker, older, multi-year ice. This year, ice older than two years accounted for less than 10% of the ice cover..."
Overall albedo is time dependent upon the extent of summer melting as well as the extent of winter coverage during the yearly cycle. Thus my "It's the volume that counts." As well as being reflective, sea ice is also both transparent and translucent: the ratio depending upon the thicknesses of ice formed from seawater (the most*transparent), of ice formed from snow crystals and refrozen snowmelt (the most*translucent), and of snow cover (the most*reflective). The transparency and translucency have a high degree of effect upon the radiative heat balance via transfer of sunlight to heat the water below that surface ice as well as in warming the ice itself.
* All three have varying amounts of reflectivity, translucency, and transparency. Just pointing out the light-handling characteristic that most distinguishes the three types from each other. And my use of 'translucency' is also illustrative -- meant to highlight internal reflection and refraction of light within the ice -- rather than scientificly literal.
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I hope it's not a trend, one year certainly isn't a certain harbinger of doom to come. Still, it's just one more thing to be unsettled about. I'm going back home to Colorado in a few weeks to spend time in the mountains. There was a discussion with my Dad that even though the snow fall was significant this year it seems to be melting off quite quickly, freeing up trails I might not otherwise be able to make. I kind of wish I didn't know why I'm going to have more fun in June...
Thanks Samprimary, interesting read. I've never seen a site that collectively groups all the counter-arguments to global warming like that.
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I just tried doing to the index of skeptical claims site and so far everthing I've clicked on gets me a "site not found message."
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"The Arctic is warmer than it's been in 2,000 years, according to a new study, even though it should be cooling because of changes in the Earth's orbit that cause the region to get less direct sunlight."
"NASA satellite measurements show that sea ice in the Arctic is more than just shrinking in area, it is dramatically thinning. The volume of older crucial sea ice in the Arctic has shrunk by 57 percent from the winter of 2004 to 2008." (quote from first article along with a different, more explanatory link)
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Some initial news from the UN ahead of the G20 summit:
quote:America talked. Canada watched. But it was China that led yesterday in an unprecedented global gathering to meet the challenge of climate change.
In a vivid example of eastern leadership, President Hu Jintao told a United Nations summit of nearly 100 world leaders that China would voluntarily deliver a four-part package of near-term carbon-cutting commitments, including the planting of nearly 40 million hectares of emissions-absorbing forest.
"At stake in the fight against climate change are the common interests of the entire world," Hu said, promising the planet's worst polluter would achieve a substantial decrease in the carbon intensity of the Chinese economy by 2020.
"Out of a sense of responsibility to its own people and people across the world, China fully appreciates the importance and urgency of addressing climate change."
China's pledge to plant a forest the size of Norway intensified the global gaze on U.S. President Barack Obama, whose message was rhetorically robust but lacked specifics.
quote:Japan added to the momentum yesterday, announcing deeper emissions-reduction targets and plans to pass cap-and-trade and renewable energy laws. India earlier this week signalled it too will make significant strides with efficiency measures and investment in wind and solar projects.
The lack of specifics from Obama spoke not only to the limits of American power but to the very structure – any promises the president makes are tentative without the approval of Congress, which is far from finished with energy and climate legislation and beset by other pressing priorities, including health-care reform.
"The announcements from other major economies should give President Obama and the Senate the confidence to act before Congress," said Jennifer Morgan of Washington's World Resources Institute. "The world has been hearing, `Yes we can,' `Yes we must,' but now needs to hear, `Yes we will.'"
Al Gore, the U.S. politician turned climate activist, hailed China's "impressive leadership. It's not widely known ... but China in each of the last two years has planted 2 1/2 times more trees than the entire rest of the world put together."
Canada was hardly a factor in the climate summit, which came a day ahead of the annual UN General Assembly that traditionally turns midtown Manhattan black and blue with armoured limousines and police escorts.
quote:Originally posted by BlackBlade: Bah, we can plant a forest the size of 2 Norways, that'll shut everybody up.
Whatever works, at least an environmental race would be better than an arms race. If an appeal to American competitiveness is what is needed, then I sure hope thats what the rest of the world will provide.
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Multiyear Arctic sea ice is effectively gone. Yep those 200foot inverted canyons of ice hovering over the ArcticOcean in which ColdWar submarines played hide&seek have mostly melted, leaving behind a couple of feet of surface ice.
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http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo694.html Antarctica is losing 190 (plus-or-minus 77) gigatonnes* of ice per year, with 132 (plus-or-minus 26) gigatonnes melting in West Antarctica. However for the first time, data clearly suggests that East Antarctica is losing ice, mostly in coastal regions, at a rate of 57 (plus-or-minus 52) Gigatonnes per year. Such signal clarity probably caused by increased ice loss since the year 2006.
* One gigatonne of ice equals about one cubic kilometer of water,
http://www.nature.com/climate/2009/0912/full/climate.2009.122.html The Greenland ice sheet lost a total of about 1500 gigatonnes of mass between 2000 and 2008 [an average of ~166 gigatonnes per year]. But from 2006 to 2008, the rate of ice loss accelerated up to 273 gigatonnes per year.
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I know SuperFreakonomics has plenty of detractors with regard to the chapter on climate change - but the idea of controlled geoengineering was very interesting. Aside from the obvious political difficulties of who would control it, etc, I'm curious as to the climate-folks' take on the issue.
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What do you mean precisely by "controlled geoengineering". Given the current state of climate science, injecting aerosol into the stratosphere (one of the common control proposals, would be extremely risky. The role of atmospheric aerosol in the earth's energy balance is the most poorly understood factor in climate science. We really can not make any quantitative prediction of what would happen if we injected large amounts of aerosol into the stratosphere. There are so many feed back effects like nucleation of ice crystals, changes in circulation, catalysis of chemical process and so forth that we can't even be certain which direction it will change things. Chances we would get it right and actually get desirable effects without large unanticipated side effects are negligible and the consequences of getting it wrong could be devastating.
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I am summarizing from memory here, so forgive me if I get things wrong.
There is a company called Intelligent Ventures, or somesuch, (IV for short), which is something of a brain-bank and patent-factory. The chapter focused heavily on them.
I know that the climate change chapter of the book has seen a lot of criticism, but most of what I've read has been about the tone and general attitude of the piece - the sensationalizing part, rather than the actual ideas presented. (Though I'm likely missing more specific critiques).
The discussion began around Mt. Pinatubo, and the global cooling effects observed after the volcano spewed sulfur into the stratosphere. Two ideas hinged on creating some sort of chimney that would pump a controlled amount of sulfer directly into the stratosphere. Sulfur was chosen specifically because the global impact of Pinatubo's eruption has been studied to death, and a re-creation of the effects of the eruption should cause a predictable result.
The first was to create a long, tube-like chimney suspended with balloons, with multiple pumps to move the sulfur. The idea was that a small amount could be released and studied, then a larger amount, etc. And the flow could always be shut off.
The second was to use sulfur already being pumped into the atmosphere from factories around the world, by extending the existing chimneys skyward with long tube-like things that would carry the gases higher up and into the stratosphere.
Another idea talked about the ocean being a massive absorber of heat energy, and clouds being a mitigating factor to that (essentially providing shade/cooling for the oceans). An idea there posited that wind-powered skiffs of some sort could be built that throw sea spray high enough into the air to form clouds, thereby reducing the amount of heat absorbed by the ocean.
Now, being a layman and a science fiction lover, these all sound "neat". I just don't know enough about the science to analyze them in any real way.
The chapter also discussed that control of these measures would be a huge political issue, namely who would get to choose how much sulfur or how many clouds to create, etc. It also discussed the negative view most environmentalists take on geoengineering, being that we shouldn't be tinkering with mother nature more than we already are.
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Ideas one and two are precisely what I was referring to when I said "inject large amounts of aerosol into the atmosphere".
Like I said, aersols are currently the biggest uncertainty in our models of climate change. Our understanding of how atmospheric aerosol influences the radiative heat balance is very bad. Injecting aerosol into the atmosphere to try to counter accumulation of greenhouse gases is extremely extremely risky and the consequences of getting it wrong are unfathomable. There is no way to test this in a preliminary experiment and once we inject huge amounts of aerosol into the atmosphere there is no way to take it back if things start going wrong.
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I think the discussion focused around Mt. Pinatubo as the preliminary experiment (it having been studied extensively), which is why the effort would be to simulate that event (albeit in a continuing fashion, rather than a one-off event)
Did you have any thoughts as to the cloud-making concept?
There was another idea by that IV group earlier in the book re: a way to limit the impact of hurricanes by cooling surface water in the Atlantic, as well.
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There have been a lot of volcanoes and a lot of studies done on their effects on climate. We still don't know anywhere near enough about those effects to be able to predict and control them.
In order to control anything, you have to have a reasonable accurate model that can predict how the changes you are making will affect what you are trying to control. This is particularly critical in any system that has "dead time", i.e. there is a significant lag between when you make the change and when you see the results. The effects of aerosol on climate are highly non-linear and their are all kinds of feed back loops. We really can't begin to accurately predict what will happen if we start pumping sulfate aerosol into the stratosphere.
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I hope it's not a trend, one year certainly isn't a certain harbinger of doom to come. Still, it's just one more thing to be unsettled about. I'm going back home to Colorado in a few weeks to spend time in the mountains. There was a discussion with my Dad that even though the snow fall was significant this year it seems to be melting off quite quickly, freeing up trails I might not otherwise be able to make. I kind of wish I didn't know why I'm going to have more fun in June...![[Smile]](smile.gif)
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