I should add to this, the following observation. Considering the many ways that the CANDU is a superior design (something I heard stated by a GE reactor service technician working on TEPCO's GE reactors in Japan, while we were hanging out in the ex-pats' bar), one might ask why enriched-uranium light-water reactors are used at all. An answer I have heard floated is that all countries who choose these designs then need to develop an enrichment facility, which can then be used to enrich uranium for *other uses*, with the power plants as convenient cover...
-Pete On Wed, 27 Feb 2013, pete wrote: > > From the article: > > > Sovacool believes the mean of 66 gCO_2 e/kWh to be a reasonable > > approximation. > > [...] > > > The largest source of carbon emissions, accounting for 38 per cent of > > the average total, is the "frontend" of the fuel cycle, which includes > > mining and milling uranium ore, and the relatively energy-intensive > > conversion and enrichment process, which boosts the level of > > uranium-235 in the fuel to useable levels. > > Going to the original journal article on which this is based > > http://www.sciencedirect.com/science/article/pii/S0301421508001997 > > and noting, as I said, that CANDU reactors use *nonenriched* > uranium, we find the gCO_2 e/kWh value for a CANDU to be: > > 15.41 > > Which compares rather favourably with "solar photovoltaic, at > 32 gCO_2 e/kWh, and six times as much as onshore wind farms, at > 10 gCO_2 e/kWh." > > The article goes on to single out the CANDU with the following > comment: > > To give an idea about how much reactor design can influence lifecycle > emissions, Boczar et al. (1998) comment that CANDU reactors are the most > neutron efficient commercial reactors, achieving their efficiency > through the use of heavy water for both coolant and moderator, and > reliance on low-neutron-absorbing materials in the reactor core. CANDU > reactors thus have the ability to utilize low-grade nuclear fuels and > refuel while still producing power, minimizing equivalent carbon dioxide > emissions. This could be why Andseta et al. (1998) conclude that CANDU > reactors have relatively low emissions (15 g CO2e/kWh) compared to the > average emissions from qualified studies as described by this work (66 > g CO2e/kWh). Others, such as Storm van Leeuwen et al. (2007), contest > these numbers and argue that the production of heavy water associated > with CANDU reactors is very energy-intensive and can produce emissions > more than a factor of one greater than the projection made by Andseta et > al. [so 30 rather than 15, still better than photovoltaic -PV] > > -Pete > > On Tue, 26 Feb 2013, D & N wrote: > > > http://www.nature.com/climate/2008/0810/full/climate.2008.99.html > > > > > > Nuclear energy: assessing the emissions > > > > *Kurt Kleiner reports on whether nuclear power deserves its reputation as a > > low-carbon energy source. > > * > > > > For decades nuclear power has been slated as being environmentally harmful. > > But with climate change emerging as the world's top environmental problem, > > the > > nuclear industry is now starting to enjoy a reputation as a green power > > provider, capable of producing huge amounts of energy with little or no > > carbon > > emissions^1 > > <http://www.nature.com/climate/2008/0810/full/climate.2008.99.html#B1> . As > > a > > result, the industry is gaining renewed support. In the United States, both > > presidential candidates view nuclear power as part of the future energy mix. > > The US government isn't alone in its support for an expansion of nuclear > > facilities. Japan announced in August that it would spend $4 billion on > > green > > technology, including nuclear plants. > > > > But despite the enthusiasm for nuclear energy's status as a low-carbon > > technology, the greenhouse gas emissions of nuclear power are still being > > debated. While it's understood that an operating nuclear power plant has > > near-zero carbon emissions (the only outputs are heat and radioactive > > waste), > > it's the other steps involved in the provision of nuclear energy that can > > increase its carbon footprint. Nuclear plants have to be constructed, > > uranium > > has to be mined, processed and transported, waste has to be stored, and > > eventually the plant has to be decommissioned. All these actions produce > > carbon emissions. > > > > Critics claim that other technologies would reduce anthropogenic carbon > > emissions more drastically, and more cost effectively. "The fact is, there's > > no such thing as a carbon-free lunch for any energy source," says Jim > > Riccio, > > a nuclear policy analyst for Greenpeace in Washington DC. "You're better off > > pursuing renewables like wind and solar if you want to get more bang for > > your > > buck." The nuclear industry and many independent analysts respond that the > > numbers show otherwise. Even taking the entire lifecycle of the plant into > > account nuclear energy still ranks with other green technologies, like solar > > panels and wind turbines, they say. > > > > > > Life studies > > > > Evaluating the total carbon output of the nuclear industry involves > > calculating those emissions and dividing them by the electricity produced > > over > > the entire lifetime of the plant. Benjamin K. Sovacool, a research fellow at > > the National University of Singapore, recently analyzed more than one > > hundred > > lifecycle studies of nuclear plants around the world, his results published > > in > > August in /Energy Policy/^2 > > <http://www.nature.com/climate/2008/0810/full/climate.2008.99.html#B2> . > > From > > the 19 most reliable assessments, Sovacool found that estimates of total > > lifecycle carbon emissions ranged from 1.4 grammes of carbon dioxide > > equivalent per kilowatt-hour (gCO_2 e/kWh) of electricity produced up to 288 > > gCO_2 e/kWh. Sovacool believes the mean of 66 gCO_2 e/kWh to be a reasonable > > approximation. > > > > "The fact is, there's no such thing as a carbon-free lunch for any energy > > source." > > > > Jim Riccio > > > > The large variation in emissions estimated from the collection of studies > > arises from the different methodologies used - those on the low end, says > > Sovacool, tended to leave parts of the lifecycle out of their analyses, > > while > > those on the high end often made unrealistic assumptions about the amount of > > energy used in some parts of the lifecycle. The largest source of carbon > > emissions, accounting for 38 per cent of the average total, is the > > "frontend" > > of the fuel cycle, which includes mining and milling uranium ore, and the > > relatively energy-intensive conversion and enrichment process, which boosts > > the level of uranium-235 in the fuel to useable levels. Construction (12 per > > cent), operation (17 per cent largely because of backup generators using > > fossil fuels during downtime), fuel processing and waste disposal (14 per > > cent) and decommissioning (18 per cent) make up the total mean emissions. > > > > According to Sovacool's analysis, nuclear power, at 66 gCO_2 e/kWh emissions > > is well below scrubbed coal-fired plants, which emit 960 gCO_2 e/kWh, and > > natural gas-fired plants, at 443 gCO_2 e/kWh. However, nuclear emits twice > > as > > much carbon as solar photovoltaic, at 32 gCO_2 e/kWh, and six times as much > > as > > onshore wind farms, at 10 gCO_2 e/kWh. "A number in the 60s puts it well > > below > > natural gas, oil, coal and even clean-coal technologies. On the other hand, > > things like energy efficiency, and some of the cheaper renewables are a > > factor > > of six better. So for every dollar you spend on nuclear, you could have > > saved > > five or six times as much carbon with efficiency, or wind farms," Sovacool > > says. Add to that the high costs and long lead times for building a nuclear > > plant about $3 billion for a 1,000 megawatt plant, with planning, licensing > > and construction times of about 10 years and nuclear power is even less > > appealing. > > > > http://wiki.answers.com/Q/What_is_the_carbon_footprint_of_nuclear_energy > > > > Natalia > > > > On 24/02/2013 8:29 PM, Ray Harrell wrote: > > > How about farming? The Pol Pot alternative? > > > > > > REH > > > > > > -----Original Message----- > > > From: [email protected] > > > [mailto:[email protected]] On Behalf Of michael > > > gurstein > > > Sent: Sunday, February 24, 2013 9:18 PM > > > To: 'RE-DESIGNING WORK, INCOME DISTRIBUTION, EDUCATION' > > > Subject: Re: [Futurework] Washington State nuclear waste leak > > > > > > Carbon based energy sources? > > > > > > M > > > > > > -----Original Message----- > > > From: [email protected] > > > [mailto:[email protected]] On Behalf Of D & N > > > Sent: Monday, February 25, 2013 12:05 AM > > > To: [email protected] > > > Subject: Re: [Futurework] Washington State nuclear waste leak > > > > > > To what? > > > > > > N. > > > > > > On 24/02/2013 12:52 PM, michael gurstein wrote: > > > > I'm not sure... depending on how you strike your frame of reference, > > > > nuclear would seem to possibly be the least worst least risk > > > alternative... > > > > M > > > > > > > > -----Original Message----- > > > > From: [email protected] > > > > [mailto:[email protected]] On Behalf Of D & N > > > > Sent: Sunday, February 24, 2013 7:02 PM > > > > To: RE-DESIGNING WORK, INCOME DISTRIBUTION, EDUCATION > > > > Subject: Re: [Futurework] Washington State nuclear waste leak > > > > > > > > This has been suggested, from time to time, by those who cannot hazard > > > > a guess as to potential for harm. The real message is--don't create it > > > > at > > > all. > > > > Natalia > > > > > > > > On 24/02/2013 9:45 AM, michael gurstein wrote: > > > > > One thing I've always wondered is why no one seems to have suggested > > > > > just sending it off into space? > > > > > > > > > > M > > > > > > > > > > -----Original Message----- > > > > > From: [email protected] > > > > > [mailto:[email protected]] On Behalf Of Keith > > > > > Hudson > > > > > Sent: Sunday, February 24, 2013 1:43 PM > > > > > To: RE-DESIGNING WORK, INCOME DISTRIBUTION, EDUCATION; pete > > > > > Subject: Re: [Futurework] Washington State nuclear waste leak > > > > > > > > > > At 09:12 24/02/2013, Pete wrote: > > > > > > > > > > > (PV) I disagree, in as much as problems at Hanford do not reflect > > > > > > anything about the current state of nuclear technology. > > > > > > Hanford is not a commercial power station, it is a federal research > > > > > > establishment and part of the weapons infrastructure The closest > > > > > > Canadian equivalent would be Chalk River, but there is really no > > > > > > equivalent as we made no attempt to refine isotopes for weapons in > > > > > > Canada. > > > > > (KH) Our equivalent in the UK is Sellafield with scores of waste > > > > > tanks (some > > > > > leaky) contaning radioactive liquids of long half-life that should > > > > > have been sequestered decades ago. One of the reasons why a solution > > > > > has not yet been found is the poor quailty of scientists and > > > > > engineers attracted to a career in nuclear projects. Whereas, 70 > > > > > years ago, it took dozens of the world's most brilliant physicists to > > > > > construct the nuclear bomb, today, most UK universities (201 out of > > > > > 203) eschew teaching nuclear engineering because they can't attract > > > > > students of any calibre. Our Nuclear Inspectorate has been under > > > strength. > > > > > > (PV) But Chalk River was a reasearch institute active during the > > > > > > early years of exploring nuclear energy, and it also has great > > > > > > warehouses full of hazardous materials. > > > > > > > > > > > > We have learned much from the activities in these projects, and no > > > > > > one today would consider storing nuclear wastes as liquids in tanks, > > > > > > certainly not from power plants, which shouldn't produce such > > > > > > material. > > > > > > > > > > > > Canadian heavy water reactors, which I might remind you, can run > > > > > > quite happily on what is considered the spent fuel of a US light > > > > > > water reactor, typically run on unenriched uranium, which requires > > > > > > no exotic processing to prepare, and when spent, in a CANDU reactor, > > > > > > it is really quite spent, and can be prepared as a solid waste block > > > > > > encapsulated in glass, and stored underground in the same mines from > > > > > > which it was extracted, nested in gravel beds in the Canadian > > > > > > Shield, where there is zero risk of groundwater contamination nor > > > > > > exposure via earthquakes or whathaveyou. > > > > > (KH) I didn't know the above, but the point is taken -- apart from > > > > > "zero" > > > > > risk. > > > > > > > > > > > (PV) I don't have any really strong opinions about the adoption of > > > > > > nuclear energy one way or the other, but most criticisms I hear of > > > > > > the industry just aren't up to speed with the current state of the > > > > > > technology. Pointing at 60 year old mistakes as a reason to dismiss > > > > > > the current technology makes no sense. > > > > > (KH) One 60 year-old mistake is that no insurance corp has yet agreed > > > > > to cover nuclear reactors. Another fact of the last 60 years is that > > > > > no civil engineering firm that has been all too eager to design and > > > > > build a reactor has yet agreed to run them and to supply electricity > > > > > at the price stated on the tin (that is, the low price that > > > > > politicians keep on telling us is the real price) -- or indeed to run > > > > > them at all. What's more -- considerably more -- is that the cost of > > > > > sequestering radioactive wastes year after year, or rather century > > > > > after > > > > century, has never yet been estimated and published. > > > > > (Even glassified blocks, buried at very deep level has to be > > > > > inspected regularly so that its safety for hundreds of generations of > > > > > humans is > > > > > assured.) The long and the short of both of the above facts is that > > > > > nuclear power has had to be subsidised before, during, and after > > > > > construction. We've never been given the true costs of > > > > > nuclear-generated > > > > electricity. > > > > > Keith > > > > > > > > > > > > > > > > > > > > > > > > > > -Pete > > > > > > > > > > > > On Sun, 24 Feb 2013, Keith Hudson wrote: > > > > > > > > > > > > > It was good to read this because I think it comes just at the > > > > > > > right > > > > > > > time to permanently affect new build in the advanced countries. > > > > > > > The > > > > > > > news of these leaks comes on top of the realization of universal > > > > > > > shale gas and ought > > > > > > now to > > > > > > > finally stop the bleatings (and false propaganda) of the wannabe > > > > > > > power > > > > > > station > > > > > > > constructors (who, be it noted, are not the slightest bit > > > > > > > interested in running them once built). > > > > > > > > > > > > > > Keith. > > > > > > > > > > > > > > > > > > > > > At 21:56 23/02/2013, Natalia wrote: > > > > > > > > Most of you have probably read this by now. Given what this news > > > > > > > > reveals, how can more new builds of such plants be justified? > > > > > > > > > > > > > > > > > > > > > > http://www.cbsnews.com/8301-201_162-57570857/wash-state-governor-6-u > > > > > > n > > > > > > d > > > > > > erground-nuclear-tanks-leaking/ > > > > > > > > Natalia > > > > > > > > _______________________________________________ > > > > > > > > Futurework mailing list > > > > > > > > [email protected] > > > > > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > _______________________________________________ > > > > > > > Futurework mailing list > > > > > > > [email protected] > > > > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > Futurework mailing list > > > > > > [email protected] > > > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > _______________________________________________ > > > > > Futurework mailing list > > > > > [email protected] > > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > > > > _______________________________________________ > > > > > Futurework mailing list > > > > > [email protected] > > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > > > _______________________________________________ > > > > Futurework mailing list > > > > [email protected] > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > > _______________________________________________ > > > > Futurework mailing list > > > > [email protected] > > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > _______________________________________________ > > > Futurework mailing list > > > [email protected] > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > _______________________________________________ > > > Futurework mailing list > > > [email protected] > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > _______________________________________________ > > > Futurework mailing list > > > [email protected] > > > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > > > > > > > _______________________________________________ > Futurework mailing list > [email protected] > https://lists.uwaterloo.ca/mailman/listinfo/futurework > > _______________________________________________ Futurework mailing list [email protected] https://lists.uwaterloo.ca/mailman/listinfo/futurework
