tag:blogger.com,1999:blog-51767065088607240632024-03-14T07:52:33.859+11:00Channelling the Strong ForceI have reached the conclusion that a positive future both for humanity, and our planet's biosphere is utterly dependent upon the success of the current global push for expanded nuclear power. The purpose of this blog is to lend what support I can to that end. The key to our future liberty is the shattering of the prison walls of electron-shell energy levels.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.comBlogger16125tag:blogger.com,1999:blog-5176706508860724063.post-3173928943506559452011-03-01T12:52:00.006+11:002011-04-28T09:28:17.135+10:00Chernobyl 25th Anniversary Fear-Fest.The 26th of April this year shall mark the twenty-fifth anniversary of the worst accident in the history of nuclear power generation, the reactor core explosion which took place in Reactor 4 in the Chernobyl Nuclear Power Plant near the town of Pripyat in what was then the Ukrainian Soviet Socialist Republic. Anti-nuclear activists and organisations around the world are gearing up to honour the event's anniversary with a predictable outpouring of propaganda aimed at frightening people out of their wits at the prospect of using nuclear power. The following article from Voice of America is doubtless one of an avalanche of similar reports which shall flood the media over the next couple of months.<br /><br /><a href="http://www.voanews.com/english/news/europe/UN-Reports-Thousands-of-Thyroid-Cancers-25-Years-After-Chernobyl-Nuclear-Disaster-117088228.html">http://www.voanews.com/english/news/europe/UN-Reports-Thousands-of-Thyroid-Cancers-25-Years-After-Chernobyl-Nuclear-Disaster-117088228.html</a><a href="http://www.voanews.com/english/news/europe/UN-Reports-Thousands-of-Thyroid-Cancers-25-Years-After-Chernobyl-Nuclear-Disaster-117088228.html"></a><br /><br /><br />It's informative to see how this report is structured. First we have the headline, which tells us "UN Reports Thousands of Thyroid Cancers 25 Years After Chernobyl Nuclear Disaster". This turns out to be rather misleading. One could be forgiven for thinking that the UN had found thousands of thyroid cancers stemming from the accident happening now, but no. The headline actually means that a UN report has found that thousands of cases of thyroid cancer were caused by the accident (which is not in dispute), and at the moment it just happens to be twenty five years since that occurred.<br /><br />We also have a photograph of a clearly distressed nine year old child, Yulia Kostina, in the intensive care unit of the Endocrinology Institute in Kiev, Ukraine, recovering from surgery to treat cancer (presumably thyroid cancer). There is no date for the photo, so the reader might be tempted to think that it is recent or current. It is actually from the year 2000, so Yulia would have been born in 1990 or 1991. The source appears to be the following article:<br /><br /><a href="http://www.time.com/time/photoessays/chernobyl/7.html">http://www.time.com/time/photoessays/chernobyl/7.html</a><br /><br />The clear implication of the photo is that Yulia's condition arose as a result of exposure to radioactive fallout from the Chernobyl accident. Most casual readers of the original article in 2000 probably thought this a reasonable conclusion, given that she was born a few years after the accident. Readers of the current Voice of America article would most likely think the same thing, even if they thought that the photo was current. After all, we all know that radioactive fallout lasts for centuries, so surely there's still plenty around to go on causing the sort of cancer the article speaks of.<br /><br />The trouble is that the danger of thyroid cancer for children in the wake of the Chernobyl accident came from the ingestion of the radioactive isotope iodine-131, a highly radioactive fission product which was released in large quantities by the explosion of the reactor core. Iodine is rapidly absorbed by the thyroid in humans, and the biological processes responsible make no distinction between ordinary non-radioactive iodine and the chemically identical radioactive isotope. Iodine-131 was deposited on grasslands, consumed by dairy cows and concentrated in milk products. The Soviet-era authorities recognised the danger and distributed iodine tablets to be given to children (if the thyroid is already saturated with iodine it wont take up any extra from contaminated milk), but it seems that many parents did not trust those authorities, and many thousands of children were unnecessarily exposed to the radionuclide. This effect caused a massive jump in thyroid cancer rates for children, and sadly, nine of those children did in fact die as a result. In the region in question, only a handful of cases would usually show each year.<br /><br />Of course, because iodine-131 is so very radioactive, it has a short half life of just over eight days. As a general rule of thumb, there is virtually nothing left of an initial mass of radioactive material after about ten half lives have elapsed. Practically all of the iodine-131 released by the accident had decayed away within three months, around four years before Yulia Kostina was born. It is simply impossible for Yulia's thyroid cancer to have been caused by the radioactive release from Chernobyl. It seems that Yulia was one of those few unfortunate children who contracted the disease as part of the normal course of events.<br /><br />The article uses extensive quotes from Dr. Fred Mettler, a respected figure in the field of radiology and a major contributor to the UN report. Dr. Mettler's comments are quite reasonable, but they are interspersed with quotes from a source many consider compromised, Professor Anders Moller, a Danish evolutionary biologist who specialises in avian evolution. Professor Moller's reputation has been under a cloud since being found guilty of misconduct by the Danish Committees on Scientific Dishonesty in 2003:<br /><br /><a href="http://www.jorgenrabol.dk/default.asp?show=misconduct"></a><a href="http://www.jorgenrabol.dk/default.asp?show=misconduct">http://www.jorgenrabol.dk/default.asp?show=misconduct</a><br /><br />Moller has recently published a study in which he claims that birds living in the Chernobyl fallout zone have smaller brains than their counterparts elsewhere. This paper has been making the rounds of the media, and came to the attention of Rod Adams, publisher of <i>Atomic Insights</i> in early February. Rod's treatment of the subject is thorough, so I will direct the reader's attention there rather than try to recapitulate his analysis. I also strongly recommend reading through the comments thread:<br /><br /><a href="http://atomicinsights.blogspot.com/2011/02/are-chernobyl-birds-really-small.html">http://atomicinsights.blogspot.com/2011/02/are-chernobyl-birds-really-small.html</a><br /><br />It is clear that Voice of America has cobbled together a bunch of factoids and misrepresented quotes from sources of widely varying credibility in order to produce a typical hyped-up anti-nuke scare story. Unfortunately we can expect plenty more of the same as the anniversary approaches.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com4tag:blogger.com,1999:blog-5176706508860724063.post-49193004476827299812010-11-26T21:30:00.033+11:002010-12-22T20:54:15.526+11:00What is uranium enrichment?The great majority of civilian nuclear power reactors currently in service are thermal reactors. Thermal reactors can only use fissile nuclei as fuel (unlike fast reactors which can also use fissionable nuclei). Natural uranium consists of over 99% non-fissile U-238, with fissile U-235 being only 0.7% of the total. Uranium fuel for a thermal reactor using light water as a moderator must have at least 3% U-235. The process of producing uranium fuel with an increased portion of U-235 is known as enrichment. The primary problem with any procedure to alter the isotopic composition of a sample of any element is that chemical processes very rarely distinguish between different isotopes of the same element, so non-chemical methods are usually necessary. This has historically tended to make enrichment technology difficult, complex, expensive and energy-intensive, although the situation has improved somewhat.<br /><br /><br /><strong>Fundamental Economic Principles Of Uranium Enrichment:</strong><br /><br />There are two basic considerations governing the economics of uranium enrichment. These are the amount of separative work and the mass of natural uranium feedstock needed to produce a given quantity of enriched uranium at a given level of enrichment.<br /><br /><br /><strong>Separative Work:</strong><br /><br />The amount of separative work needed for uranium enrichment is measured in special units known as Separative Work Units (SWU). The SWU is a measure of the amount of work done in the process of seperating isotopes. They are usually expressed in units of kilogram SWUs, or tonne SWUs. An SWU will require different amounts of energy depending on the enrichment process used. A detailed description of the SWU can be found on the following site:<br /><br /><a href="http://www.fas.org/programs/ssp/nukes/effects/swu.html">http://www.fas.org/programs/ssp/nukes/effects/swu.html</a><br /><br /><br /><strong>Natural Uranium Feedstock Mass:</strong><br /><br />In addition to the separative work units provided by an enrichment facility, the other important parameter to be considered is the mass of natural uranium required to yield a desired mass of enriched uranium. As with the number of SWUs, the amount of feedstock material required will depend on the level of enrichment desired and upon the amount of U-235 that ends up in the DU. Unlike the number of SWUs required during enrichment, which increases with decreasing levels of U-235 in the depleted stream, the amount of natural uranium needed will decrease with decreasing levels of 235U that end up in the DU.<br /><br /><br /><strong>Economic Consequences of the Interaction Between SWUs and Feedstock Mass:</strong><br /><br />Putting these two factors together in an illustrative example, in the enrichment of LEU for use in a light water reactor it is typical for the enriched stream to contain 3.6% U-235 (as compared to 0.7% in natural uranium) while the depleted stream contains 0.2% to 0.3% U-235. In order to produce one kilogram of this LEU it would require approximately 8 kilograms of natural uranium and 4.5 SWU if the DU stream was allowed to have 0.3% U-235. On the other hand, if the depleted stream had only 0.2% U-235, then it would require just 6.7 kilograms of natural uranium, but nearly 5.7 SWU of enrichment. Because the amount of natural uranium required and the number of SWUs required during enrichment change in opposite directions, if natural uranium is cheap and enrichment services are more expensive, then the operators will typically choose to allow more U-235 to be left in the DU stream whereas if natural uranium is more expensive and enrichment is less so, then they would choose the opposite.<br /><br /><br /><strong>Downblending and the Megatons To Megawatts Program:</strong><br /><br />Another factor which has influenced the economics of uranium enrichment over the past two decades is the practice of downblending. This is the production of LEU for reactor fuel by dilution of HEU sourced from nuclear warheads with depleted uranium. this has been done since 1995 under the auspices of the Megatons To Megawatts program mandated by the 1993 United States-Russia nonproliferation agreement, with 400 tonnes of Russian HEU processed into fuel for US reactors as of September 2010. This fuel has provided half the power currently generated by US civilian reactors. The program is scheduled to end in 2013, by which time a total of 500 tonnes of HEU from former Soviet warheads will have been consumed. The termination of this program will likely increase the demand for enrichment services around the world.<br /><br /><br /><br /><strong>Enriched Uranium Grades:</strong><br /><br />Uranium can be enriched to any desired level depending on the amount of separative work performed. There are a number of recognised enrichment levels.<br /><br /><br /><strong>Depleted Uranium (DU):</strong><br /><br />DU is the uranium resulting from the tails of the enrichment process, so named because it is depleted in U-235 compared to natural uranium. DU usually has a U-235 content of 0.2-0.3%<br /><br /><br /><strong>Slightly Enriched Uranium (SEU):</strong><br /><br />SEU is a relatively new grade of enriched uranium with U-235 levels between 0.9% and 2%. SEU is sometimes used in preference to natural uranium for heavy water reactors, and has been proposed as the fuel type for the ACR-1000 reactor design, intended as an advanced variant of the CANDU series.<br /><br /><br /><strong>Low-Enriched Uranium (LEU):</strong><br /><br />LEU is uranium which has been enriched to less than 20% U-235 composition. Uranium fuel for LWRs is usually enriched to between 3% and 5%. Research reactors and medical isotope production reactors typically use higher levels of enrichment, around 12% or more. The OPAL reactor at Lucas Heights uses uranium enriched to just below 20% U-235.<br /><br /><br /><strong>Highly Enriched Uranium (HEU):</strong><br /><br />HEU is uranium enriched to above 20% U-235. It is used in some research and isotope production reactors, and is also used in nuclear power plants for naval vessels such as nuclear submarines and aircraft carriers, where the high enrichment levels allow for compact plant designs.<br /><br /><br /><strong>Weapons-Grade Uranium (WGU):</strong><br /><br />HEU enriched to 85% U-235 and above is also known as weapons-grade uranium. This is the grade of uranium used in the production of some nuclear weapons.<br /><br /><br /><br /><strong>Enrichment processes:</strong><br /><br />The art of uranium enrichment extends back to the Second World War, when a number of approaches were rushed through development under the pressure of military demand. Some early techniques which were abandoned in favour of more effective methods were thermal diffusion, which exploited the tendency of lighter isotopes to diffuse toward warmer surfaces and heavier isotopes toward colder, and electromagnetic isotope separation, which used a powerful magnetic field to separate beams of uranium ions into different streams according to atomic mass. These techniques were largely abandoned in favour of gaseous diffusion, and more recently, the gaseous centrifuge process.<br /><br /><br /><strong>Gaseous Diffusion:</strong><br /><br />Gaseous diffusion was the first uranium enrichment process employed on a large scale in the civilian nuclear power sector. It was first employed at the Oak Ridge facility for the Manhattan Project during the Second World war, and was later used in a number of nations around the world for their civilian nuclear power programs. In this process, uranium is combined with fluorine in the form of Uranium Hexafluoride (UH6) gas and forced through semi-permeable membranes, producing a slight separation of molecules carrying U-235 and U-238. The process is based on Graham's Law, which describes the tendency of lighter molecules to escape from a container with a semi-permeable membrane wall faster than heavier molecules. By employing a cascade of many stages, any given degree of U-235 enrichment can eventually be reached.<br /><br />Gaseous diffusion is an energy-intensive process, requiring on the order of 2,500 kilowatt hours to perform one kilogram SWU. Producing LEU for LWR fuel using gaseous diffusion requires approximately one fortieth of the amount of power eventually obtained from it. The gaseous diffusion process currently produces about 33% of the world's enriched uranium.<br /><br /><br /><strong>Gaseous Centrifuge Process:</strong><br /><br />The gas centrifuge process uses rotating cylinders to concentrate the heavier isotope around the rim and harvest the U-235-rich portion from near the rotation axis. This process is much more efficient than the older gaseous diffusion process, requiring as little as 2% of the energy to perform equivalent separative work. A gaseous centrifuge plant can perform one kilogram SWU for around 50-60 kilowatt hours. Gaseous centrifuge plants currently produce about 54% of the world's enriched uranium.<br /><br />An improved centrifuge known as the Zippe centrifuge (named after Gernot Zippe, the German scientist credited with its invention), uses a temperature gradient along the length of the cylinder to enhance the separation of light and heavy isotopes. This type has been used by the commercial firm Urenco for uranium enrichment, and is also believed to have been used by Pakistan in its nuclear weapons program.<br /><br /><br /><strong>Laser Enrichment:</strong><br /><br />Some laser enrichment techniques have also been considered. The one currently receiving the most interest is the SILEX process, standing for Separation of Isotopes by Laser Excitation. The SILEX process is of special interest to Australia as the CSIRO played a large role in its development. SILEX is currently being developed by GE Hitachi Nuclear Energy in agreement with Silex Systems. Details of the process and performance are heavily classified, but it is said that SILEX offers an order of magnitude better performance over the gaseous centrifuge process.<br /><br />Two other laser enrichment techniques have also been investigated. These are AVLIS (Atomic Vapour Laser Isotope Separation) and MLIS (Molecular Laser Isotope Separation). These techniques have encountered technical difficulties which have shut down most efforts to develop them.<br /><br /><br /><strong>Other Enrichment Techniques:</strong><br /><br />Some development work has been done on other processes, occasionally reaching the pilot plant stage, and in at least one case a full scale operational plant. The most significant of these has probably been the Helikon Vortex Separation Process developed by South Africa's UCOR corporation. UCOR operated a plant in from the 1970s through to 1991 using this technology to produce LEU for civilian nuclear fuel and WGU for South Africa's nuclear weapons program. The technique consists of forcing a stream of UH6 diluted with hydrogen tangentially into a shaped tube at near the speed of sound. The tube thus acts as a non-rotating centrifuge. The process uses large amounts of electricity, has substantial cooling requirements, and is therefore not considered economic for the production of reactor fuel. Over its operational lifetime the plant is said to have produced hundreds of kilograms of HEU. An alternative aerodynamic process has been used in a demonstration plant in Brazil which faced similar issues to the South African plant, and has also been shut down.<br /><br />In addition to these aerodynamic approaches, chemical separation processes and plasma separation processes have also been tried. Most of these efforts have been shut down or scaled back, and none currently make a significant contribution to world uranium enrichment capacity.<br /><br /><br /><strong>Proliferation Issues:</strong><br /><br />Uranium enrichment is one of the most sensitive stages of the nuclear fuel cycle because of its potential to produce weapons-grade uranium. Uranium must be enriched to over 85% U-235 before it is suitable for nuclear weapons production, but it is still the same process used to create LEU for civilian nuclear fuel, although carried through to a far higher level. Enrichment capacity is therefore regarded as a potential nuclear proliferation threat, which is why Iran's uranium enrichment program has received so much sceptical attention from the international community.<br /><br />Although the long-term nuclear future lies with breeder reactor technology, the main expansion in nuclear infrastructure over the next few decades will almost certainly be of the LWR type, requiring a reliable supply of LEU for reactor fuel on the global market. There are preliminary moves underway led by the International Atomic Energy Agency in cooperation with Russia, the United States and others to establish international uranium enrichment centres for the provision of LEU to the international market. This is intended to guarantee supply to the many nations now expressing interest in developing their own civilian nuclear power programs, thereby diminishing the justification for new players to develop their own national uranium enrichment capacity. Australia could potentially play a role in this system by establishing an international enrichment centre here, using either gaseous centrifuge technology or SILEX technology, enriching locally mined uranium to LEU levels and providing it to clients who have signed up to the program. In this way, Australia could play a major role in limiting the spread of nuclear weapons capability throughout the world during this particular historical phase of the use of nuclear power. Establishing such a centre would also assure Australia of local supply of LEU fuel for our own nuclear plants once we've established our domestic nuclear power industry.<br /><br /><br /><strong>Further information:</strong><br /><br />More details on the subject of uranium enrichment can be found on the following sites:<br /><br /><a href="http://www.fas.org/programs/ssp/nukes/effects/swu.html">http://www.fas.org/programs/ssp/nukes/effects/swu.html</a><br /><br /><a href="http://www.world-nuclear.org/info/inf28.html">http://www.world-nuclear.org/info/inf28.html</a><br /><br /><a href="http://en.wikipedia.org/wiki/Enriched_uranium">http://en.wikipedia.org/wiki/Enriched_uranium</a><br /><br /><a href="http://energyfromthorium.com/2010/08/06/loveswu1/">http://energyfromthorium.com/2010/08/06/loveswu1/</a><br /><br /><a href="http://energyfromthorium.com/2010/08/07/loveswu2/">http://energyfromthorium.com/2010/08/07/loveswu2/</a><br /><br /><a href="http://energyfromthorium.com/2010/08/09/loveswu3/">http://energyfromthorium.com/2010/08/09/loveswu3/</a><br /><br /><a href="http://energyfromthorium.com/2010/08/15/loveswu4/">http://energyfromthorium.com/2010/08/15/loveswu4/</a><br /><br /><a href="http://energyfromthorium.com/2010/08/24/vis-value-function/">http://energyfromthorium.com/2010/08/24/vis-value-function/</a>Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com4tag:blogger.com,1999:blog-5176706508860724063.post-78298576032679966812010-05-07T14:42:00.008+10:002010-05-11T23:50:08.151+10:00Mining Nuclear Fuel.<strong>Overview:</strong><br /><br />The fuel for nearly all current nuclear reactors ultimately derives from the world's uranium resource. Reactors using fuel sourced from thorium are also possible, and the present generation of LWRs can use uranium bred from thorium as fuel, but this technique is not in widespread use. The greater story of obtaining nuclear fuel is thus the story of uranium mining.<br /><br /><strong>Current world uranium production:</strong><br /><br />In 2009, 50,572 tonnes of uranium was mined worldwide. Kazakhstan led production with 13,820 tonnes (27%), Canada produced 10,173 tonnes (20%) and Australia 7,982 tonnes (16%), although Australia has the largest commercially extractable reserves as currently defined.<br /><br /><strong>Mining techniques:</strong><br /><br />There are three main techniques in use for uranium mining. These are open pit mining, underground mining, and in situ leach mining. In open pit mining, the overburden of material is blasted and excavated away to reveal the ore body, which is then blasted, excavated and removed with loaders and dumptrucks. Underground mining is carried out in the same manner as for other underground mines, with access tunnels, and drilling and blasting. In situ leach mining involves drilling boreholes down into an ore body, pumping a leaching fluid into the ore and then pumping the resulting solution to the surface to extract the uranium. The leaching fluid is sometimes a combination of hydrogen peroxide and sulphuric acid (Australia), sometimes high concentration sulphuric acid alone (Kazakhstan), or sometimes an alkaline solution (United States), depending on the nature of the ore body. The World Nuclear Association states that 7% of the world's uranium mined in 2009 was extracted as a by-product to other mining activity. That figure includes the uranium produced at Olympic Dam.<br /><br /><strong>Health concerns:</strong><br /><br />The anti-nuclear movement often claims that uranium mining is a highly dangerous and environmentally hazardous practice. The examples used to support these claims generally come from the mid-20th century, such as the often quoted case of the Navajo uranium miners in the United States during the 1950s. Significant numbers of Navajo miners went on to develop small cell carcinoma in later life. This was determined to result from exposure to radon-222, a natural radioactive decay product deriving from uranium which was concentrated in poorly ventilated mine tunnels. Radon is often present in all kinds of underground mines because uranium is a common, widely distributed element in earth's crust. Underground coal mines often have elevated uranium concentrations and thus high radon levels. Proper ventilation and toxic gas removal systems are essential safety measures for all underground mining operations, not just uranium mines. <br /><br />Workers in open pit mines are usually inside the sealed cabins of vehicles, and water is sprayed in the mine to settle dust particles. In situ leach mining protects workers from the risk of radon by never exposing them to it.<br /><br />Uranium contamination of ground water is a possibility and needs to be managed. The health risk of ingesting uranium comes from the chemical toxicity (roughly similar to that of lead), and first manifests in mammals as kidney damage. Uranium is too weakly radioactive to present a radiotoxicity problem. Most experts consider the health impacts of uranium mining to be of the same order as mining for other heavy metals, such as gold, or lead.<br /><br />It should be understood that the regulations governing the mining, refining, enrichment and milling of uranium are now so extensive and encompassing that uranium is very likely the most heavily regulated mineral in the world.<br /><br /><strong>Resources and reserves:</strong><br /><br />According to the World Nuclear Association, as of 2007 the global known recoverable reserves of uranium were 5,469,000 tonnes. The largest national share of that reserve was Australia (1,243,000 tonnes, 23%), followed by Kazakhstan (817,000 t, 15%), Russia (546,000 t, 10%), South Africa (435,000 t, 8%), Canada (423,000 t, 8%), USA (342,000 t, 6%), Brazil (278,000 t, 5%), Namibia (275,000 t, 5%), Niger (274,000 t, 5%), Ukraine (200,000 t, 4%) and Jordan (112,000 t, 2%).<br /><br />These reserves are presently extractable at a cost of US$130/kg or less. Uranium was extracted from phosphate deposits in the United States and Belgium prior to 1998, and could be again if the price of uranium rises enough. The uranium resource associated with the phosphate reserves is estimated to be 27 million tonnes. There are many similar low grade uranium deposits which could be tapped if the price of uranium rises much above the current level. The price of uranium is not a major factor in the price of nuclear power, and could increase many times over the current level before significantly impacting the cost of nuclear power for the end user.<br /><br /><strong>Environmental footprint and comparisons with other energy sources:</strong><br /><br />What kind of environmental footprint does mining for nuclear fuel and related minerals have, and how does it compare with other electrical generation technologies? <a href=" http://www.citris-uc.org/system/files?file=CITRIS_Peterson_06.ppt">This powerpoint presentation</a> by Dr. Per Peterson, professor and chair of nuclear engineering at Berkeley, presents figures on concrete and steel requirements for nuclear, wind, coal and combined cycle natural gas (see slide 11). Working through the numbers and adding fuel to the total, we arrive at the following figures for the mining needed to produce 1 megawatt.year of electrical energy (1MWe.y) for each technology:<br /><br /><em><strong>Nuclear:</strong></em><br /><br />676 tonnes (0.74t steel + 8.44t concrete + 666.7t U ore at 300ppm)<br /><br /><em><strong>Wind:</strong></em><br /><br />680 tonnes (123t steel + 557t concrete)<br /><br /><em><strong>Coal:</strong></em><br /><br />~5,500 tonnes (4.19t steel + 16.4t concrete + 5,500t coal)<br /><br /><em><strong>Combined Cycle Natural Gas:</strong></em><br /><br />963 tonnes (0.147t steel + 2.88t concrete + 960t gas)<br /><br />These numbers need some qualification for their proper significance to be appreciated. The final figures for the fossil fuel power sources only use the mass of fuel finally consumed. If the same method had been used for nuclear power, the mass of natural uranium mined as fuel would have been 0.2 tonnes, yielding a final figure for nuclear power of 9.38 tonnes, far below any of the others. Critics could justifiably point out that uranium ore is usually far more dilute than the coal or gas resources, and insisted that the mass of raw ore needed should be considered. The grade for the ore body at the Rossing mine in Namibia of 300ppm, one of the poorest ore bodies currently mined, was used to obtain the 676 tonne figure.<br /><br />The figure for wind power is almost identical, but wind has severe and most likely unresolvable issues with variability and intermittency which render it all but useless for inclusion in the power grid of an industrial society.<br /><br />The figure for coal power is dominated by mining for the fuel to the extent that mining for plant building materials falls into the noise. From the mining perspective, coal is the worst offender by far.<br /><br />Natural gas requires much less fuel mass than coal, but suffers other problems associated with its extraction. Wide publicity has recently been given to the newly discovered shale gas reserves in the United States, which are said to represent a significant extension of global reserves. Experience is now showing that these reserves cannot be accessed without extensive damage to large areas of underground rock layers, with associated earth tremors and serious gas leaks resulting in significant environmental difficulties in the regions being exploited.<br /><br />Finally, the figure for nuclear power assumes the use of light water reactor technology. This is the current standard in power reactor technology, and is likely to remain so for the next few decades, but following that it is likely that most new nuclear capacity will be breeder reactors. The figure for fuel mining for nuclear power above is based on the assumption that 200 tonnes of natural uranium is to be mined for 1 tonne of fissile fuel, but a well-designed fast breeder reactor can eventually consume all the natural uranium, so the mining requirement shrinks to 0.5% of that figure. This would bring down the fuel mining figure for nuclear power from 666.7 tonnes to 3.35 tonnes. The amount of structural steel and concrete required for a breeder reactor compared to a light water reactor may change somewhat, but even if it is ten times that of an LWR (which it won't be, and it may well be less), the total mining requirement remains far less than that of the competitors.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com11tag:blogger.com,1999:blog-5176706508860724063.post-54000819960651156932010-03-02T23:03:00.053+11:002010-05-10T22:56:56.900+10:00Is Nuclear Power Sustainable?For nuclear power to be a viable solution to our future energy requirements, we need a plentiful supply of nuclear fuel which can be accessed without inordinate effort. There are occasional claims from anti-nuclear activists that there are insufficient rich ore bodies for an expansion of nuclear power, or that the energy used to mine and mill the fuel produces an excessive carbon footprint. The truth is that there are huge reserves of nuclear fuel available for exploitation in Earth's crust, and the carbon footprint associated with the nuclear fuel cycle is quite small now, and likely to shrink further in the future.<br /><br />Current nuclear plants run on U-235 and sometimes on Pu-239 reprocessed from earlier fuel burns or recycled from decommissioned nuclear weapons. Natural uranium consists mainly of U-238, with U-235 making up only 0.7% of the total. In practice, this means that for roughly every 200 tonnes of natural uranium mined, only one ton of fissile U-235 fuel is produced (some U-235 is left behind by the enrichment process). It is possible to improve this figure by reprocessing used fuel to recover some of the unburned U-235 as well as the plutonium produced during the fuel burn, but this doesn't change the order-of-magnitude calculations on fuel availability for LWRs. As a rough rule of thumb, one tonne of fissile fuel can generate 1 GW.year (1GW.y) of energy as electricity. This is true of all three important fissile isotopes, U-235, Pu-239 and U-233.<br /><br />How much generating capacity should we allow for? Demographic trends indicate the global population reaching about ten billion people mid-century and stabilising at that level. For that stability to be reached, people will need a certain minimum standard of living and energy consumption.<br /><br />The average global electrical generating capacity for 2009 was about 2.2 terawatts (2.2TW, or 2.2 trillion watts). Divided among the estimated 6,790,000,000 humans alive as of July 2009, this provided 325 watts/person. Of that output, actual power consumed was 301 watts/person. For comparison, Chad currently consumes 1 watt/person, Ghana 27 watts/person, India 56 watts/person, China 293 watts/person, Poland 384 watts/person, South Africa 500 watts/person, Britain 646 watts/person, Germany 759 watts/person, France 780 watts/person, Netherlands 848 watts/person, Australia 1,176 watts/person, the United States 1,439 watts/person, and Sweden 1695 watts/person. These figures are for electricity consumption only.<br /><br />If the global population plateaus at 10 billion, we will need a 50% increase in generating capacity by 2050, taking us up to 3.3TW, just to maintain the current per capita consumption. In reality there will be more development in the currently underdeveloped world, as well as in the First World. There is also likely to be greater electrification of the economy, with functions such as transportation, desalination, fertiliser production and other processes using electricity rather than fossil fuel combustion. It's not unreasonable to suggest that we may have around 5TW of electrical generating capacity by 2050. <br /><br />If all this electricity were to come from nuclear power plants, we would need to burn 5000 tonnes of fissile fuel each year. Is this sustainable? Can we use more if necessary? Is this a permanent solution to the energy crisis, or is it at best a useful stopgap until a more sustainable power system can be developed? To answer these questions we need to understand the magnitude of the global nuclear fuel resource.<br /><br />The table below was compiled for the January 1980 edition of Scientific American. Both it and the associated commentary are taken from the <a href="http://nuclearinfo.net/Nuclearpower/OneCompletePage">nuclearinfo.net site</a>, reproduced here with the kind permission of Dr. Martin Sevior:<br /><br /><br /><em><strong>Uranium Distributions in the Earth's Crust </strong><br />The following table is from Deffeyes & MacGregor, "World Uranium resources" Scientific American, Vol 242, No 1, January 1980, pp. 66-76.</em> <br /><br /><em>type of deposit--------------------------------estimated tonnes-----estimated ppm <br /><br />Vein deposits----------------------------------2 x 10^5--------------10,000+<br /><br />Pegmatites, unconformity deposits-------2 x 10^6--------------2,000-10,000 <br /><br />fossil placers, sand stones------------------8 x 10^7--------------1,000-2,000 <br /><br />lower grade fossil placers,sandstones----1 x 10^8--------------200-1,000 <br /><br />volcanic deposits-----------------------------2 x 10^9--------------100-200 <br /><br />black shales-----------------------------------2 x 10^10-------------20-100 <br /><br />shales, phosphates---------------------------8 x 10^11-------------10-20 <br /><br />granites----------------------------------------2 x 10^12-------------3-10 <br /><br />average crust----------------------------------3 x 10^13-------------1-3<br /><br />evaporites, siliceous ooze, chert-----------6 x 10^12-------------.2-1 <br /><br />oceanic igneous crust-----------------------8 x 10^11-------------.1-.2 <br /><br />ocean water----------------------------------2 x 10^10-------------.0002-.001 <br /><br />fresh water-----------------------------------2 x 10^6--------------.0001-.001 <br /><br /><br />“The total abundance of Uranium in the Earth's crust is estimated to be approximately 40 trillion tonnes. The Rossing mine in Namibia mines uranium at an ore concentration of 300 ppm at an energy cost 500 times less than the energy it delivers with current thermal-spectrum reactors. If the energy cost increases in inverse proportion to the ore concentration, shales and phosphates, with a uranium abundance of 10 - 20 ppm, could be mined with an energy gain of 16 - 32. The total amount of uranium in these rocks is estimated to be 8000 times greater than the deposits currently being exploited.”</em> <br /><br />In his book <a href="http://www.withouthotair.com/">'Sustainable Energy — without the hot air'</a>, Professor David Mackay, Dept. of Physics, University of Cambridge gives an estimate of how much of the uranium resource could be considered accessible with conventional extraction techniques. Noting that phosphate deposits have been mined for their uranium content in America and Belgium prior to 1998, Professor Mackay combines the current proven economic uranium reserves and the phosphate reserves to reach a figure of 27 million tonnes of easily recoverable uranium. This figure has increased a bit since the figures used by Mackay were published and will likely increase again, so we'll round it up to 30 million tonnes for our calculations. He also notes recent development work on the recovery of uranium dissolved in seawater by Japanese researchers, reported to be achievable at US$100-300/kg UO3. This reserve is calculated to be 4.5 billion tonnes.<br /><br />Allowing for 5TW of nuclear power generation using LWRs burning 1 tonne of U-235/GWe.y we need 5000 tonnes of U-235 per annum, which equates to 1,000,000 tonnes of natural uranium per annum. This would exhaust our 30 million tonne reserve in just thirty years. Assuming we can extract half the oceanic uranium, we have a 2,000 year supply. This would require 220 million tonnes of the adsorbent cloth, with a cross-sectional collection area of 24,000 square kilometres submerged under the sea. This is not impossibly huge, but it is substantial, and could arguably have a significant impact on marine ecosystems. Nonetheless it is conceivable that with oceanic uranium extraction we could run our civilisation at above its current per capita electricity consumption for a span of time as long as that which separates us from the Roman Empire using technology no more advanced than current LWRs.<br /><br />But will this be sufficient? The world currently boasts 2.2 TW of electrical generating capacity, but the average ongoing global energy use is around 15TW. Most of this comes from the burning of fossil fuels for transport, heating, industrial processes, agriculture, primary industry and so forth. The bounty of fossil fuel bequeathed to us by nature will one day no longer be available, whether by failure to effectively compete, legislative fiat, or eventual depletion. Can nuclear power replace non-electric energy applications, and if so, can it be sustained?<br /><br />Fortunately the answer to the first question is yes, nuclear power can certainly replace most if not all applications presently met by fossil fuels. Nuclear reactors produce great quantities of heat which can be used as process heat for chemical industries, desalination, synthetic fuel production, fertiliser production, district heating, and many other applications. It is even thought that nuclear power may assist in making many processes more efficient than they are today. For instance, a fleet of electric cars with batteries charged by nuclear power plants would be considerably more energy-efficient than an equivalent fleet of our current petrol and diesel cars.<br /><br />The answer to the second question depends on just how much energy is needed to cover all reasonable demands which civilisation might place on its power source. It has sometimes been suggested that 10-11TW would be sufficient for a well-organised nuclear powered world of ten billion people. This may be so, although such a world may be a bit more economically constrained on average than developed nations are today. In such a future, the ocean uranium reserve referred to previously still suffices to run things for an equivalent span of time separating the present from Saxon England.<br /><br />The historical pattern of human energy utilisation, however, speaks against any assumption of reduced power use. The norm has been the opposite, with people using ever more power per capita as time goes by. This trend has continued in spite of occasional advances in energy efficiency. Also, in the long run it is likely that the developing world will catch up to the developed, and the aspirations of billions of people will force energy consumption ever higher. Eventually we should expect that First World standards will be the norm for all people. While increasing electrification of the world economy may result in some efficiencies, there are likely to be new uses for power, possibly including energy-intensive geoengineering efforts to mitigate climate fluctuations. The per capita power consumption from all sources (electric and non-electric) for the United States is now around 10kW. Accepting this as a convenient working figure for standard per capita consumption, we find we need to plan for 100 terawatts of electrical power generation to ensure sufficient capacity for a world population of 10 billion.<br /><br />One hundred terawatts requires the fissioning of 100,000 tonnes of fissile fuel each year. If we are to rely on LWRs, this will consume 20 million tonnes of natural uranium per annum. Lets see how our various uranium reserves stack up:<br /><br />Our initial uranium reserve of 30 million tonnes now disappears in a year and a half. The ocean reserve, once again assuming 2 billion tonnes, is exhausted after a century. Referring to the World Uranium Resources table above, we see there are about 22 billion tonnes of natural uranium present in concentrations of 20 ppm or more. This reserve is sufficient for 1,100 years. It is probably not possible to supply LWRs from uranium at lower concentrations.<br /><br />Extracting large quantities of uranium from such low grade feedstock will require ever more infrastructure to maintain supply. The ocean extraction system, for example, would need 11 billion tonnes of adsorbent cloth with a cross-sectional collection area of nearly half a million square kilometres. Light water reactor technology now encounters its limits. The LWR can be a good stopgap measure, but it is not the key to a truly sustainable future. It is capable of taking us to through the middle of this century, but must soon after yield its dominant position to the breeder reactor.<br /><br />Breeder reactors are nuclear reactors which utilise part of their neutron flux to transmute non-fissile nuclei into fissile nuclei which can then be burned in the reactor. Uranium-238 can be bred into plutonium-239, and thorium-232 into uranium-233. This capability gives breeder reactors a much greater supply of fissile fuel than LWRs. Plutonium breeders can fission the entire supply of natural uranium. All naturally occurring thorium, with an abundance four times that of uranium, can be bred into uranium-233 and fissioned. It is instructive to see how this impacts nuclear fuel reserves.<br /><br />Our original 30 million tonnes of uranium now provides our 100TW civilisation with 300 years of power. The 2 billion tonne ocean reserve is good for 20,000 years. The larger 22 billion tonne reserve of uranium above 20 ppm concentration can now provide 220,000 years of power. But this is not the limit of the breeder's potential. As well as greatly extending the usefulness of existing reserves, breeder reactors also unlock vast quantities of low grade ore for our use. To demonstrate this, we'll take a look at how the capabilities of the breeder applied to average continental crust can revolutionise the scale of the energy resources available to humanity.<br /><br />Average continental crust contains 2.7 ppm (parts per million) of uranium and 9.6 ppm of thorium, totalling 12.3 ppm of fissile and fertile fuel. We want to extract 100,000 tonnes of fuel each year for our 100TW civilisation. How much average rock and dirt do we need to dig up on an annual basis for this? The answer is we need to excavate about 8.2 billion tonnes of earth. For comparison, about 6.8 billion tonnes of coal was mined worldwide in 2009. Out of this, about 5 billion tonnes went to electricity production, which produced 40% of the world's electrical power, about 0.9TW (these figures were derived from information on the <a href="http://www.worldcoal.org/">World Coal Institute</a> website). It should be noted that the density of coal varies from around 1.1 to 1.5 tonnes/m^3, but the average density of Earth's crust is 2.7 tonnes/m^3. While the mass of material mined from average crust to obtain our 100,000 tonnes of nuclear fuel is greater than the mass of coal mined in 2009, the volume of material disrupted would be smaller. <br /><br />Once we have mined our 8.2 billion tons of perfectly ordinary and unremarkable rock and dirt, we need to extract the nuclear fuel. This could be done by grinding, chemical treatment, pyroprocessing or whatever is most suitable for the particular minerals in question. We may get a reasonable estimate to the upper bounds of the energy required for this process by assuming the ore is completely melted. The power required to melt the same mass of silicon (the second most common element in Earth's crust after oxygen) is about 723 GW.y. It is likely that the whole separation process could be accomplished with less than 1TW.y of energy. This operation corresponds to an extraction and milling rate of 260 tonnes of crust each second.<br /><br />What is the size of the resource? Let's assume that only the portion of continental crust currently under dry land is exploited for its uranium and thorium content, to a depth of roughly four kilometres (the deepest mine currently operating is the TauTona mine in Carletonville, South Africa at 3,900m, and the Kola Superdeep Borehole in Russia is 12,262m). This represents a reserve of 20 trillion tonnes of fertile and fissile fuel, capable of powering our 100TW civilisation for 200 million years. This is the span of time separating us from the dawn of the Jurassic Period, when the supercontinent Pangaea was starting to break apart into Laurasia and Gondwana. Dinosaurs were just beginning to make their mark on the world, and the allosaurus, stegosaurus and diplodocus were yet to evolve.<br /><br />It will be a very long time before whoever comes after us in the far distant future will need to worry about mining ordinary crust. The science is clear: There is more than enough high grade uranium ore in the short term to allow us to transition to a completely nuclear-powered economy during this century, and a supply of fuel for the breeder reactors of the future so vast as to leave no doubt that nuclear power is completely sustainable in any meaningful sense of the word for far beyond the probable lifetime of our civilisation, and indeed, of our species.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com7tag:blogger.com,1999:blog-5176706508860724063.post-27360670038755229882010-02-23T09:00:00.012+11:002010-10-02T16:28:33.488+10:00How Do Nuclear Reactors Work?Nuclear fission reactors are machines that facilitate a sustained fission reaction in suitable materials, usually for the purpose of electrical power production. Most nuclear fission reactors currently in use are uranium-235 burning thermal spectrum light water reactors, so I shall describe this type first, then look at the alternatives.<br /><br /><br /><strong>Light Water Reactors:</strong><br /><br />Light water reactors get their name from their moderating fluid, which is ordinary water. This is called “light water” because the water molecules have ordinary hydrogen atoms with one proton and no neutrons as the H2 component of H2O. Some nuclear reactors use heavy water as a moderator, which has deuterium (heavy hydrogen), with one proton and one neutron, as the H2 component. Heavy water reactors will be described later. There are two basic types of light water reactor in popular use, the Pressurised Water Reactor (PWR) and the Boiling Water Reactor (BWR). The PWR is the most common.<br /><br /><strong>Pressurised Water Reactors:</strong><br /><br />Modern PWRs are built around certain basic components:<br /><br /><strong>Reactor Core:</strong><br /><br />The reactor core is that part of the reactor where the nuclear fuel assemblies are located and the fission reaction takes place. The shell of the core is known as the pressure vessel in a light water reactor, as part of its function is to contain water and steam at high pressure.<br /><br /><strong>Nuclear Fuel:</strong><br /><br />The fuel for a nuclear reactor generally consists of pellets of uranium oxide embedded within zirconium alloy (zircaloy) tubes, which are arranged into bundles called fuel assemblies. The uranium in the fuel has been enriched to consist of 3-5% fissile U-235 rather than the natural level of 0.7% U-235.<br /><br /><strong>Moderator:</strong><br /><br />The moderator is a substance which slows neutrons emitted naturally by the uranium fuel to thermal velocities, enabling them to be captured by U-235 nuclei and initiate fission reactions. Moderator material needs a high proportion of very light elements in order to absorb the kinetic energy of the neutrons rather than just reflecting them with little loss of velocity. Hydrogen in water (H2O) is well suited to this purpose, and light water is used as the moderator in most current reactors.<br /><br /><strong>Control Rods:</strong><br /><br />Control rods are long rods inserted between fuel assemblies for the purpose of absorbing neutrons before they can participate in a fission reaction, thus controlling the reaction rate. They are made of elements with high neutron absorption cross sections, such as silver, indium, cadmium, boron, and others.<br /><br /><strong>Coolant:</strong><br /><br />The coolant is a fluid which keeps the temperature of the reactor core under control by removing heat. It also serves the critically important function of delivering this heat to a secondary cooling loop which drives a turbine to produce electric power. Because water is both a highly effective moderator and coolant, it serves both roles in a light water reactor.<br /><br /><strong>-Primary coolant loop.</strong> The primary coolant loop pumps water in a continuous cycle through the reactor core, then through the steam generator of the secondary loop, then back into the core for the next cycle. The water is pressurised to remain liquid at operating temperature. There is no exchange of water between the primary loop and the secondary loop.<br /><br /><strong>-Secondary coolant loop.</strong> The secondary coolant loop contains water which is boiled in the steam generator using heat from the primary loop. The steam is then used to drive a turbine for electricity production before being cooled by the tertiary loop and recondensed to flow through the steam generator again. There is no exchange of water with the primary or tertiary loop.<br /><br /><strong>-Tertiary coolant loop.</strong> The tertiary loop is an open cycle which takes water from a source outside the plant and uses it to cool the secondary loop by condensing the steam after it has driven the turbine. This water has no direct contact with water in the secondary or primary loop. It is used once, then discharged into the environment, usually at a temperature a few degrees higher than it had when taken into the plant.<br /><br />The basic features listed above show how a nuclear reactor works in broad outline; Fuel bundles are placed in the reactor core. Neutrons emitted naturally by the uranium fuel are slowed by the moderator to thermal velocity and then set off subsequent fission reactions which liberate more neutrons to continue the process. The energy released by these reactions heat the coolant, which transfers heat energy through the primary and secondary loops to drive a turbine for power production. The fission reaction rate is managed with the assistance of neutron-absorbing control rods. Excess heat is taken away by the tertiary cooling loop.<br /><br /><br /><br />There are other important components to a nuclear plant not directly related to power generation.<br /><br /><strong>Containment Structure:</strong><br /><br />Containment refers to the barriers built into the reactor to shield the environment from radioactive material. Modern light water reactors have multiple layers of containment. The first level is the ceramic structure of the uranium oxide fuel pellets which trap fission products within the lattice. The next is the zircaloy cladding for the fuel. The third is the reactor vessel and cooling system. The final containment is the steel-reinforced concrete structure known as the containment building in which the reactor is situated. This is the ultimate backup if all else fails, and is designed to withstand high internal pressure to contain the steam released by a breach of the pressure vessel. They are also now designed to withstand attacks from outside such as missile strikes and impacts of large aircraft.<br /><br /><strong>Radwaste Facility:</strong><br /><br />Nuclear plants need a facility to store used fuel after it has been removed from the core. The used fuel contains highly radioactive fission products which must be sequestered from the environment for some time before it can be moved to permanent storage. The first unit in the radwaste system is the spent fuel pool. This is a pool about forty feet deep where the spent fuel is kept while it cools down for several years. Spent fuel initially has a high temperature, maintained by the decay of high-level fission products. Storage in the spent fuel pool helps to prevent melting, and also provides shielding from the high level radioactivity of the spent fuel.<br /><br />After about a decade the shortest lived and most highly radioactive fission products have decayed away, and the spent fuel can be removed from the pool to be sealed in steel-reinforced concrete containers for above ground storage.<br /><br /><br /><strong>Boiling Water Reactors:</strong><br /><br />BWRs are similar to PWRs, but are operated at a lower pressure. Instead of maintaining the water in the pressure vessel as a pressurised liquid, the water in a BWR is allowed to partially boil and drive a steam turbine directly, without using a secondary coolant loop. Because the turbine is in direct contact with steam from the reactor core, extra containment precautions are taken in the turbine hall of a BWR.<br /><br />In the United States, the civilian nuclear power plant fleet consists of 69 PWRs and 35 BWRs.<br /><br /><strong>Alternative reactor types:</strong><br /><br />There are many possibilities for reactor design beyond the ordinary light water variety. We will look at these in turn in subsequent essays.<br /><br />-Heavy water reactors.<br /><br />-Fast breeder reactors.<br /><br />-Gas-cooled reactors.<br /><br />-Molten salt reactors.<br /><br />-Aqueous reactors.<br /><br />-Small modular reactors.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com3tag:blogger.com,1999:blog-5176706508860724063.post-63037725839866526612010-01-27T22:40:00.007+11:002010-04-12T17:32:53.358+10:00What Is Nuclear Fission?Nuclear fission is a natural phenomenon where atomic nuclei split into smaller ‘daughter’ nuclei, releasing large amounts of energy in the process. Many atomic nuclei are fissionable, meaning that they can be split by being hit with neutrons. Out of these nuclei, three are of special interest to humanity because the manner in which they split releases enough free neutrons for a self-sustaining chain reaction to occur among neighbouring atoms of the same isotope. This makes it possible to build nuclear reactors for practical power production. The nuclei in question are two uranium isotopes, U-233 and U-235, and one plutonium isotope, Pu-239. These are called fissile isotopes.<br /><br />Out of the three fissile isotopes, only U-235 occurs naturally on Earth, where it composes 0.7% of natural uranium. The other two can be produced artificially by exposing certain other nuclei to neutron radiation to transmute them into other isotopes which then undergo radioactive decay to become the desired fissile isotopes. This process of irradiating non-fissile nuclei in order to convert them into fissile nuclei is called breeding. Non-fissile nuclei which can be bred into fissile nuclei are called fertile. The precursor fertile isotopes are:<br /><br />1) Thorium-232, which can be transmuted to Th-233, decaying to protactinium-233, then to U-233.<br /><br />2) Uranium-238, which can be transmuted to uranium-239, which will then decay to neptunium-239, which ultimately decays to Pu-239.<br /> <br />Uranium-238 composes over 99% of natural uranium, which is roughly as abundant as tin in the earth's crust. Thorium is roughly four times as common as uranium, and consists of 100% Th-232.<br /><br />Nuclear fission can be further classified according to the velocity of the neutrons initiating the process. Neutrons emitted from an atomic nucleus typically have a velocity of around 14,000 km/s, about 5% of the speed of light. These are known as fast neutrons, and nuclear reactors which utilise them are known as fast reactors. The chief advantages of fast reactors is that they liberate more neutrons per collision in the fission process, which enables more efficient fuel breeding, and the energy of the collision is high enough to fission most actinides such as U-238, rather than just U-235 as usual. The chief disadvantage is that fast neutrons have a very small capture cross-section for their target nuclei, thus reducing the likelihood of fission-inducing collisions.<br /><br />It is possible to slow neutrons down by exposing them to elements with light nuclei. These absorb most of the momentum of the collisions until the neutrons are travelling at only a couple of kilometres per second. This velocity corresponds to room temperature. These are known as thermal neutrons, and nuclear reactors designed to make use of them are known as thermal reactors. The vast majority of current nuclear power plants are thermal reactors. The chief advantage of thermal fission reactions is that they have a much larger capture cross-section with their target nuclei than fast reactions, thereby increasing the likelihood of a fission event. The disadvantages are that they cannot initiate fission in non-fissile nuclei such as U-238, and they release insufficient neutrons to achieve a break-even breeding rate for converting U-238 to Pu-239. Thermal neutrons can achieve break-even breeding of U-233 from Th-232, but this property has not yet been widely exploited.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com5tag:blogger.com,1999:blog-5176706508860724063.post-24024115157149922962009-10-04T16:55:00.011+11:002010-05-12T01:29:20.237+10:00Pax Atomica: The Nuclear Peace.<strong><span id="SPELLING_ERROR_0" class="blsp-spelling-error"><span id="SPELLING_ERROR_0" class="blsp-spelling-error">Pax</span></span> <span id="SPELLING_ERROR_1" class="blsp-spelling-error"><span id="SPELLING_ERROR_1" class="blsp-spelling-error">Atomica</span></span> Prologue:</strong><br /><br />I'm posting the following material here so I can link to it when the topic arises in discussion and debate elsewhere. This post is an essay I wrote some time ago concerning the influence of nuclear weapons on the nature of international relations since the end of World War II. Shortly thereafter, pro-nuclear commenter <span id="SPELLING_ERROR_2" class="blsp-spelling-error"><span id="SPELLING_ERROR_2" class="blsp-spelling-error">DV</span></span>8 2XL provided an analysis on the same subject which went into more specific detail concerning the strategic and tactical considerations of nuclear weapons. Whereas I look at the subject in the light of the doctrine of Mutually Assured Destruction, <span id="SPELLING_ERROR_3" class="blsp-spelling-error"><span id="SPELLING_ERROR_3" class="blsp-spelling-error">DV</span></span>8 2XL asserts that the true value of nuclear weapons is their conferral of invulnerability to invasion to any country which possesses them. With nuclear weapons, a small state can repel invasion by huge conventional forces and also ward off the threat of nuclear attack by possessing a retaliatory capability. This shielding effect would be lost the instant it chose to use nuclear weapons in a first strike attack, so there would be strong incentive on both sides to maintain the peace.<br /><br />Either way you look at it though, nuclear weapons have been an inadvertent force for peace in the world.<br /><span style="font-size:78%;"><strong><span style="font-size:180%;"></span></strong><br /></span><strong><span style="font-size:180%;"><span id="SPELLING_ERROR_4" class="blsp-spelling-error"><span id="SPELLING_ERROR_4" class="blsp-spelling-error">Pax</span></span> <span id="SPELLING_ERROR_5" class="blsp-spelling-error"><span id="SPELLING_ERROR_5" class="blsp-spelling-error">Atomica</span></span></span></strong><br /><br />I have in my possession a most interesting tome. No doubt many here have heard of it. It's titled "The Rise and Fall of the Great Powers: Economic change and military conflict from 1500 to 2000", written by Paul Kennedy a professor of History at Yale University. There you will find an excellent description of the ongoing pattern of Great Power conflicts over that period. It's a very impressive read. If you haven't read it yet, I highly recommend that you obtain a copy and do so. You will almost certainly complete it with much greater knowledge and appreciation of the subject than you had when you started.<br /><br />The book is partly a forecast, as it was written in 1986. Professor Kennedy's insight into the situation at the time was uncanny. He stated that the Soviet Union was in deep trouble a few years before its collapse, and wrote of the rise of China well before that topic became a mainstream day-to-day issue. Nothing in what he said about the remainder of the twentieth century needs much revision now that it's over, except perhaps that some of the projections overestimated the time frame for major changes, but you probably wouldn't have found too many people in 1986 asserting that Soviet communism was likely to collapse within five years. A 'Great Power' is defined as a nation capable of presenting a credible challenge to any other nation in the world. The nations in the first rank change over time, as various contenders get pushed out of the leader pack, while demographic and economic evolution thrusts others into it.<br /><br />What really strikes me about the historical account is the dreary regularity with which the Great Powers take up arms against each other. Throughout most of modern European history, the Great Powers have engaged in ongoing struggles for dominance, with intervals of peace merely serving as prep time for the next bout. Every twenty years or so (or perhaps less, I haven't worked out the average), Europe would go through some huge convulsion to reach a new equilibrium in its internal tribal tensions.<br /><br />Since the Renaissance there have been two periods of relative calm, during which direct Great Power wars have been rare or non-existent. The first of these ran from 1815 to 1914, from the victory of Britain and its allies over Napoleon's empire to the outbreak of World War One. That extended period of international peace appears chiefly to be the result of the dominance of one Great Power above all others. Britain found itself in a uniquely advantageous position after the Napoleonic Wars. In a bid to secure their thrones against any future revolutions, the freshly restored monarchies of the Continent established something called the Concert of Europe. Devised by the Austrian nobleman and diplomat Metternich, the 'Concert' was basically an agreement among the European absolutist monarchies to come to each other's aid to put down any popular revolution against any established regime which might threaten the status <span id="SPELLING_ERROR_6" class="blsp-spelling-error"><span id="SPELLING_ERROR_6" class="blsp-spelling-error">quo</span></span>.<br /><br />The reactionary nature of post-Napoleonic Continental governments slowed the introduction of industrial technology and modern representational management and government, and entrenched Britain's position as <span id="SPELLING_ERROR_7" class="blsp-spelling-error"><span id="SPELLING_ERROR_7" class="blsp-spelling-error">hegamon</span></span>. This situation lasted until the late nineteenth century when the spread of industrialisation across Europe and the U.S. enabled Britain's rivals to close the gap. There were wars during this period, including a couple of direct clashes between Great Powers, but not on the scale of the previous century. The greatest military struggle by far in that historical period was the American Civil War, an internal matter for the United States rather than a Great Power conflict, and one which mirrored to some extent the tensions which also existed in Europe at the time between the old agrarian economic system and the new industrial system. The other notable struggles of this period occurred during the latter part of it, and mainly concerned the altering balance of power in Central Europe with the rise of Prussia/Germany.<br /><br />As time went by, Britain slipped from overwhelming <span id="SPELLING_ERROR_8" class="blsp-spelling-error"><span id="SPELLING_ERROR_8" class="blsp-spelling-error">hegamon</span></span> to first among equals in the Great Power game, and finally to eclipse at the rise of Germany, the US, Russia and others. Once it could no longer overawe its neighbours, Europe drifted into another Great Power war, this time dragging the rest of the world in with it. In the aftermath of the destruction wrought by WW1, many people from all levels of society across Europe and the rest of the world sought political solutions to the problem of war, such as the League of Nations, and invested great effort in devising them. In spite of their earnest efforts to avoid another disaster, the world was plunged into another, much worse, Great Power war two decades later. In spite of the best efforts of the forces of reason, the basic historical pattern had reasserted itself when the exceptional conditions which facilitated the long peace of the 19<span id="SPELLING_ERROR_9" class="blsp-spelling-error"><span id="SPELLING_ERROR_9" class="blsp-spelling-error">th</span></span> Century vanished. Restoration of the normal distribution of power among the people of the globe meant restoration of business as usual, no matter what the angels of our better nature thought of it.<br /><br />Then something peculiar happened. For some reason, direct armed clashes between the Great Powers have ceased. By now we should be up to about World War Five, or be desperately arming ourselves in preparation for it. The international situation at the end of World War Two certainly didn't encourage much optimism about the chances of avoiding future Great Power clashes, at least not if you used past history as any guide. Something happened to derail business as usual.<br /><br />That something was, of course, nuclear weapons. The Balance of Terror, Mutually Assured Destruction, was bagged out in its time, but in retrospect, it seems to have served humanity rather well. Of course, it's still in effect. The fall of the USSR hasn't really changed the fundamental strategic situation that much. Russia could still destroy the US and China. The US could still destroy Russia and China. China could cause enough damage to the US or Russia to dissuade either of those Powers from attacking it. There are still client states and proxy wars, but there are no true Great Power wars. Such a conflict is still far too dangerous for any of the main players to countenance.<br /><br />Since the thermonuclear bomb cannot be uninvented, I'm inclined to think that it must be acknowledged as a permanent feature of human politics from hereon in. Nukes or something even more powerful will be primary strategic considerations in human affairs for the rest of history. Even if some kind of defensive technology such as advanced ABM lasers, or interceptors, or something becomes possible, no one could ever be sure that an advanced delivery system couldn't get past the defence. The risk would be just too high to ever assume invulnerability to attack.<br /><br />In short, the only way that nuclear aggression can ever possibly make sense in terms of a Great Power war is if the aggressor has good reason to think that its victim cannot retaliate. I don't know what it would take to convince a would-be nuclear conqueror that it was safe to launch a first strike, but it is certainly more likely to happen if the intended victim publicly declares itself to be disarmed, than if it has a habit of occasionally conducting an underground weapon test to prove to everyone that its nuke capability is current and effective.<br /><br />The <span id="SPELLING_ERROR_10" class="blsp-spelling-error"><span id="SPELLING_ERROR_10" class="blsp-spelling-error">Pax</span></span> Britannia lasted 99 years. The <span id="SPELLING_ERROR_11" class="blsp-spelling-error"><span id="SPELLING_ERROR_11" class="blsp-spelling-error">Pax</span></span> <span id="SPELLING_ERROR_12" class="blsp-spelling-error"><span id="SPELLING_ERROR_12" class="blsp-spelling-error">Atomica</span></span> is now nearly 63 years old. I wonder if it will outlive its predecessor, and if it does, by how long.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com10tag:blogger.com,1999:blog-5176706508860724063.post-38655489435430502642009-06-06T10:36:00.013+10:002009-06-21T11:50:20.593+10:00The Pressing Need For Vast Power.According to Australia's Chief Scientist, Professor Penny Sackett, the world has just six years to begin reducing its CO2 emissions or climate change catastrophe will ensue down the track:<br /><br /><a href="http://www.abc.net.au/news/stories/2009/04/20/2547879.htm">http://www.abc.net.au/news/stories/2009/04/20/2547879.htm</a><br /><br />There has also been some talk of geoengineering measures which might be taken to alleviate climate change if it does look like getting out of hand:<br /><br /><a href="http://www.msnbc.msn.com/id/30112396/">http://www.msnbc.msn.com/id/30112396/</a><br /><br />I think it's pretty clear that we're not going to reach Professor Sackett's cutoff point for serious reductions. Too much time has been wasted, and we cannot build the necessary infrastructure by the target date. Even if sensible measures to reduce CO2 emissions are commenced tomorrow, we will still overshoot safe atmospheric CO2 levels by a huge margin.<br /><br />Many years ago in the lost days of my youth, I lived downstairs from a young man who lived for cars... working on them, fixing them, talking about them, and above all, cheating death in them by pushing the limits of high-speed, hard-edged driving past the point which would turn any sane person pale with terror. I did not particularly like him, but we conversed occasionally, and while I regard most of what he had to say as self-justifying blither, he once said something to me which has peculiar relevance to the situation we find ourselves in now. The words were spoken about twenty-four years ago, so my memory of them may be a little off, but the gist is this:<br /><br /><em>"People think that small cars are safer than big cars, but they're not. You have less protection in a small car than a big car, and you can get yourself into just as much trouble in a small car. A small car has enough power to get you into real trouble, but not enough power to get you out of it. A big car has even more power to get you into trouble, but it has enough power to get you out of it again."</em><br /><br />It was the most sensible thing I ever heard him say.<br /><br />And so true! A small car can indeed get you into strife it does not have the power to avoid which a larger, more powerful car could (in the hands of a skilled driver) avert. Herein lies a metaphor for our AGW woes.<br /><br />If we follow the advice of 'renewables' and 'conservation/efficiency' advocates, we will deliberately cast away our ability to implement large-scale geoengineering solutions to AGW. For the sake of our own safety, we must make sure a high-power, high-energy power production system is available to meet our needs. For a lot of obvious reasons ably articulated elsewhere (see links on right hand side of blog), nuclear fission must be the heart of such a system. We need to point out to people just what a dangerous path a low-energy future would really be, especially if (as seems likely) we need to address major climate change in a non-passive manner.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com36tag:blogger.com,1999:blog-5176706508860724063.post-6668969495318325392008-11-23T20:23:00.001+11:002009-04-21T00:27:22.623+10:00Time for Australia to relent on the issue of uranium sales to India.The United States has signalled its dismay with China’s decision to assist Pakistan with the construction and operation of two new nuclear reactors:<br /><a href="http://indiatoday.digitaltoday.in/index.php?option=com_content&task=view&id=20647&sectionid=4&issueid=80&Itemid=1">http://indiatoday.digitaltoday.in/index.php?option=com_content&task=view&id=20647&<span class="blsp-spelling-error" id="SPELLING_ERROR_0">sectionid</span>=4&<span class="blsp-spelling-error" id="SPELLING_ERROR_1">issueid</span>=80&<span class="blsp-spelling-error" id="SPELLING_ERROR_2">Itemid</span>=1</a><br /><br />China for its part is not really taking a lot of notice, and can be expected to move ahead with the deal. It is known that Pakistan is the nation with possibly the worst nuclear proliferation record in the world. Potential nuclear proliferation is, of course, the justification given by the Rudd government for not selling Australian uranium to India. Funnily enough, China’s long-standing relationship with Pakistan raised no red flags over the issue of uranium sales to China. In fact, Martin Ferguson is quite chirpy over the deal:<br /><a href="http://www.world-nuclear-news.org/ENF-Australia_starts_shipping_uranium_to_China-2111086.html">http://www.world-nuclear-news.org/ENF-Australia_starts_shipping_uranium_to_China-2111086.html</a><br /><br />It’s true Australia has insisted that Australian uranium only be used in certain designated reactors for electricity production, but since uranium is a fungible commodity this <span class="blsp-spelling-error" id="SPELLING_ERROR_3">doesn</span>’t really mean much. Uranium China has purchased from elsewhere will now be freed up for use in Pakistani reactors, and, who knows, perhaps eventually Pakistani bombs.<br /><br />If we are willing to sell uranium to China and thus indirectly facilitate supplies to China’s allies such as Pakistan, why are we refusing to sell uranium to India? Surely it is in our interests to join with our western allies in fostering a strategic relationship with this emergent Great Power, not to mention our environmental interests to assist India to develop its CO2-free energy sector.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com1tag:blogger.com,1999:blog-5176706508860724063.post-55603575510994000832008-11-17T19:46:00.003+11:002008-11-17T19:50:33.004+11:00Nuclear Power Enables German Utility To Offer Affordable CO2-Free Electricity Option.German electricity utility RWE has come out swinging against Germany’s absurd nuclear phase-out policy with a new electricity purchasing package for consumers based on a mix of 68% nuclear power and 32% renewables, mainly hydroelectric. The story can be found here:<br /><br /><a href="http://www.world-nuclear-news.org/EE-RWE_launches_zero_carbon_supply_option-1411086.html">http://www.world-nuclear-news.org/EE-RWE_launches_zero_carbon_supply_option-1411086.html</a><br /><br />Although the power purchased through the scheme will be slightly more expensive than usual, RWE has stated that baring changes to taxes, the power will remain at a fixed cost until 2011. It is being promoted to consumers concerned about CO2-induced global warming.<br /><br />This is not the first scheme of its kind to be marketed in Europe. Finnish utility Fortum has also marketed two carbon emission-free packages, one costing slightly more than usual based on nuclear power, and another devoted to electricity produced by non-nuclear renewable sources, which is more costly:<br /><br /> <a href="http://www.world-nuclear-news.org/energyEnvironment/Fortum_launches_electricity_eco-labels-210108.shtml">http://www.world-nuclear-news.org/energyEnvironment/Fortum_launches_electricity_eco-labels-210108.shtml</a><br /><br />Predictably enough, reactionary anti-nuclear campaigners from the German chapter of Greenpeace have denounced the RWE initiative in their usual soundbite press release style.<br /><br /><em>“Greenpeace Germany is critical of the new plan. "'Pro-Climate' is just a label. The product is in no way ecological. It does nothing to help the environment," Andree Bohling, an energy expert with Greenpeace Germany, told Spiegel Online.”</em><br /><br />Yeah, right. Anyhow, that quote comes from the following story:<br /><br /><a href="http://www.nuclearpowerdaily.com/reports/Power_company_offers_nuke-heavy_power_plan_999.html">http://www.nuclearpowerdaily.com/reports/Power_company_offers_nuke-heavy_power_plan_999.html</a><br /><br />I hope that German consumers will chose wisely with regard to this new option for purchasing their electricity and send a clear message to decision makers, underlined in Euros. Unfortunately it looks like it will be quite some time before Australian consumers will have the luxury of expressing a similar preference.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com4tag:blogger.com,1999:blog-5176706508860724063.post-51289411481725976472008-11-09T13:49:00.008+11:002011-06-17T20:53:30.484+10:00Affordable Power For The Future.It is interesting and sometimes mildly entertaining to occasionally kick back and watch the cycle of arguments fielded by anti-nuclear activists in their eternal quest for the extinction of nuclear power. I have witnessed this both on the net and in my personal contact with acquaintances of the anti-nuke flavour. It is entertaining in the long haul, but frustrating in the short term. The cycle goes something like this:<br /><br />Anti-nuclear activist (ANA): “Nuclear power is not a viable source of energy because of X.”<br /><br />Pro-nuclear advocate (<span id="SPELLING_ERROR_0" class="blsp-spelling-error">PNA</span>): “Your argument is incorrect for the following reasons.” (Provides reasons).<br /><br />ANA: “OK, I see your point, but it <span id="SPELLING_ERROR_1" class="blsp-spelling-error">doesn</span>’t matter because nuclear power is not viable on account of Y.”<br /><br /><span id="SPELLING_ERROR_2" class="blsp-spelling-error">PNA</span>: “Argument Y is also incorrect on account of the following.” (Demonstrates fallacy of argument Y).<br /><br />ANA: “Very well, but you haven’t considered argument Z.”<br /><br /><span id="SPELLING_ERROR_3" class="blsp-spelling-error">PNA</span>: “What?? Very well then!” (Disposes of Z)<br /><br />ANA: “Yes, you are clearly right about Z, but what about argument A?”<br /><br />This sequence continues until finally we get back to:<br /><br />ANA: “Yes, you are absolutely correct that argument W is without merit, <em>but what about argument X??”</em><br /><br />Presented in such terms, the sequence is obvious and childish, but I have seen supposedly intelligent adults hide behind that tactic when arguing against nuclear power. Actually, drop the ‘supposedly’. I know that some of these people, who include some very good friends of mine, are unquestionably of high intelligence. The cyclic nature of the debate with them is, I suspect, more of the nature of a religious dialogue than a scientific one.<br /><br />As a tactic for presenting their case to the public, the anti-nuclear movement is clearly onto a winner. The pro and anti nuclear cases are generally presented in the media as single-issue isolated events, with the connections to associated issues rarely built into a rational whole. The general public is thus left with the impression that an ongoing scientific controversy exists over, say, the safe disposal of radioactive wastes, when in fact the technology for dealing with that particular ‘problem’ has been around for decades, and no competent scientist working in the field doubts it.<br /><br />The actual period of the cycle has a direct relationship to the size of the anti-nuclear entity you are conversing with. The cycle of argument with an individual might be completed within an evening, or even go through several cycles in an evening. A debate on the net with a cadre of committed anti-nukes might last for days or weeks. When you consider the anti-nuclear movement as a whole, the debate surrounding one particular point might go on for months.<br /><br />At the moment, the anti-nuclear movement is trying to make an issue out of the cost of nuclear power. Since this is the flavour of the moment for the antis, their chosen battleground on which they presently perceive headway might be made, I shall commence my series of posts on current nuclear issues addressing that topic.<br /><br /><strong><span style="font-size:130%;">So what is the cost of nuclear power?</span></strong><br /><br />This is not an easy question to answer currently in terms of dollars/kW. Unlike coal, the cost of fuel is not a major factor in the ultimate cost of the power delivered to the consumer. The fuel requirements for a nuclear power plant are so minimal that great increases in the price of uranium ore or enriched uranium fuel won’t really have much of an effect on the price paid by the end-consumer of the power generated. The largest cost input to nuclear power by far is the cost of constructing the plant in the first place. In this sense nuclear power plants are less like coal or natural gas power plants than they are like hydroelectric dams. The bulk of the cost is the up-front capital cost of construction.<br /><br />There are many inputs into the construction of an asset as large and complex as a nuclear plant, but humans have been building them for five decades now, so we should have some experience to go by. Why is it currently so hard to pin down a ballpark figure for the construction of new nukes? Why has the anti-nuke crowd seized on this issue of late?<br /><br />The anti-nuclear activists have seized on nuclear plant construction costs because the cost estimates for construction have lately gone through the roof. I recall back in 2005 when I started searching the net for information about nuclear power that at the time, firms like GE-Westinghouse were confidently predicting plant construction costs on the order of US$1000-2000/KW output. I believe the current estimates to be 4-6 times in excess of this. What the hell happened? The anti-nukes will happily inform the public of this increase, but rarely look to the reasons why.<br /><br />The primary reason for the great increase in construction cost directly relates to the increase in price of the construction materials for the plants. The price for new nuclear power plants has gone through the roof because the price of the stuff they’re mainly made out of has gone through the roof. The stuff in question is steel and concrete.<br /><br />In my previous post I stated that I’d be linking to sites and studies which have looked at these issues in more detail. In that spirit, please check out the following:<br /><br /><a href="http://jkwheeler.podomatic.com/entry/2008-05-26T18_43_50-07_00">http://jkwheeler.podomatic.com/entry/2008-05-26T18_43_50-07_00</a><br /><br />You can find a link to John’s site in the links section of this blog. I recommend following it and learning what you can from it. Now for a brief summary of the germane material inputs for nuclear power and other power sources based on the data from a study by Professor P.F. Peterson of <span id="SPELLING_ERROR_4" class="blsp-spelling-error">UC</span> Berkeley undertaken in 2005. Professor Peterson determined that for each megawatt of power output from a new nuclear plant, 40 metric tons of steel and 190 cubic metres of concrete are required. For the bulk of plant construction costs, take current prices for those commodities and multiply them by the number of megawatts of electrical power output. The price of plant construction, and by extension the ultimate cost of power from the plant, is determined by commodity prices over the period of construction. I’m sure we can all appreciate that these are difficult to determine in advance, especially in such turbulent times for the global economy.<br /><br />Something that <span id="SPELLING_ERROR_5" class="blsp-spelling-error">isn</span>’t so subject to sudden alterations is the relative demand for those commodities by competing energy technologies. No matter the current price of concrete or steel, the amounts required for obtaining a megawatt of reliable power from a nuclear reactor, a wind farm, or a coal plant are (barring technological breakthrough) pretty much fixed.<br /><br />The two non-nuclear examples provided in John Wheeler’s article are wind and coal. For an output of 1 megawatt of power a coal plant requires 98 metric tons of steel and 160 cubic meters of concrete. A wind farm requires 460 tons of steel and 870 cubic meters of concrete (each of those wind turbines might look slender and graceful from a distance, but they are Behemoths in their own right, and you need a hell of a lot of them to provide the same level of power as a standard nuclear plant). This is not an academic exercise. The rise in price for basic construction materials over the past two years (driven by rising demand from China and India) has caused the UK to do an abrupt about-face on its plans for massive wind infrastructure to meet the government’s mandate for its renewable energy target. Sticker shock has even forced the cancellation of some new coal plants, and that’s before any carbon tax has been imposed on their operation. In contrast, major utilities in the US are determined to press ahead with their plans for a new nuclear build because they recognise that in spite of increasing costs, the alternatives are rising in price with the tide as well, and nuclear retains its comparative cost advantage. This will remain true no matter what the global financial situation may be four years from now, when the first suite of proposed new plants reaches the conclusion of their licensing procedure. The input price may go up, it may go down, it may go round and round, but nuclear still wins.<br /><br />Given the above, it is no mystery why the anti-nuclear movement likes to harp on about the cost of new nuclear build… but <span id="SPELLING_ERROR_6" class="blsp-spelling-error">doesn</span>’t care to provide too many details as to just why this is.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com8tag:blogger.com,1999:blog-5176706508860724063.post-37955708188828169892008-11-09T08:47:00.000+11:002008-11-09T08:49:22.612+11:00So When Is Finrod Going To Start Talking About Nuclear Power?I have received some criticism concerning the content of this site. To wit, there isn’t really all that much stuff here yet that is actually about nuclear power. It is a valid criticism. This results from my history of being a commenter on other pro-nuclear blogs for a couple of years now. During that time I have become quite familiar with many dimensions of the subject of nuclear power, its risks, costs, advantages, challenges, history, paths taken and not taken, potential fuel sources and so on. It is abundantly clear to me that there is a huge pool of talented pro-nuclear people out there, both within and outside the professional nuclear community who are far more qualified than I to present these matters to the public. So why am I doing this at all?<br /><br />I am doing this because:<br /><br />A) In my view, the advantages of nuclear power are so obvious that even an unqualified outsider should (with a little research) be able to defeat the anti-nuclear case in a logical discussion of the issue with even the most expert of anti-nuclear activists.<br /><br />B) I tend to have my own take on certain matters which are not always illuminated to my satisfaction by other pro-nuclear advocates.<br /><br />C) I have at whiles observed that one or two fairly basic, homely observations of mine have ended up in the pro-nuclear meme pool, without attribution to myself. This is quite OK by me. If some small observation of mine helps the cause I don’t mind not being credited with it, but it does point to the possibility for valid contributions to the debate which are original to me, so I should avail myself of every opportunity to make them.<br /><br />So getting back to the original point, I started this blog very much in the context of my previous 2-3 years worth of commentary on other blogs, and set out initially to supplement the excellent body of work already in existence, rather than attempting to reinvent the wheel at the outset. Hence my first posts were on topics which I felt had been neglected by their obscurity, or directly related to some topical discussion on a side aspect of the field.<br /><br />It is clear, however, that some of my readers are not very familiar with the basics of the pro-nuclear case and have looked to my blog in vain to be filled in. I shall therefore post a few articles outlining that case in very basic form, and provide links to other sites with more detailed expositions, to give people something to go on with.<br /><br />I am also considering doing a few articles on power generation issues in my local area, namely the Australian Capital Territory and surrounding districts in New South Wales, as well as some articles on energy issues currently concerning Australia.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com3tag:blogger.com,1999:blog-5176706508860724063.post-70303466196475220262008-10-29T19:20:00.005+11:002008-11-02T07:48:37.457+11:00Carbon Dioxide surface sequestration with alkaline earth silicates: A response to G.R.L. Cowan.A couple of weeks ago I posted a comment in response to this post by Rod Adams on the Atomic Insights Blog:<br /><br /><a href="http://atomicinsights.blogspot.com/2008/10/comparing-scale-of-used-nuclear-fuel-to.html">http://atomicinsights.blogspot.com/2008/10/comparing-scale-of-used-nuclear-fuel-to.html</a><br /><br />The next comment on the thread was from G.R.L. <span class="blsp-spelling-error" id="SPELLING_ERROR_0">Cowan</span>, who denied that CO2 sequestration was a <span class="blsp-spelling-error" id="SPELLING_ERROR_1">pipedream</span>, and proposed that excess CO2 can be neatly sequestered by reacting it with crushed alkaline earth silicates, such as olivine and serpentine. There was something of a debate on that thread which I <span class="blsp-spelling-error" id="SPELLING_ERROR_2">shan</span>’t recapitulate here. I did not participate, as my knowledge of the field was inadequate for me to do so. Nonetheless it was an intriguing proposition, and I have been considering it ever since. I was actually inspired to get in touch with an old friend who I have not contacted for many years to get his input. He holds a doctorate in chemistry, although he hastens to add that his field of specialisation is polymer chemistry and he is unwilling to declare confidently one way or the other on the practicality of this proposal. He did state that he considers the term ‘clean coal’ an oxymoron, and shares my opinion that the ideal carbon sequestration strategy is to leave the coal where it is in the first place, but he also concedes that the chemistry for alkaline earth silicate sequestration does work, although we might question the economics. Here following is the email he sent me in reply, which he has graciously permitted me to quote:<br /><br /><em>Ahoy <span class="blsp-spelling-error" id="SPELLING_ERROR_3">Finrod</span>, An interesting ramble which covers many possibilities, but facts are more difficult especially since so much is at its infancy. A perfunctory glance at the net shows the chemistry is well known i.e. it is scientifically established process. However, while the thermodynamics may be favourable, evidently the kinetics are not so much so. In other words, while the overall journey may be downhill, it is uphill for at least part of the way. Getting over the activation hump is the key and there are 2 main ways to achieve this: a) wait for long enough - scatter the stuff around and walk away in expectation it will do its thing eventually. Grinding it up finely is one way to accelerate the process - after all these rocks have been sitting around for millions of years. If not for this activation energy I would expect life could be quite startling as rocks randomly exploded around us, especially if we breathed on them. b) force the issue using e.g. heat/catalysis as discussed in article below (which I selected more or less randomly). This all involves more inputs. So while thermodynamics may rule, kinetics will dictate when this will happen. I am not sufficiently knowledgeable to say if and when this process would become viable, but as we discussed on the phone, there is a hell of a lot of work and machinery involved in locating and crushing all these rocks....and all of this is consuming other resources and generating other byproducts. And are there other side effects of all the dust and carbonates we are generating in the process? CO2 is not our sole enemy.</em><br /><br />The ‘article below’ referred to is:<br /><br /><em>Making rocks<br />Nature has the best track record for sequestering carbon dioxide from the air into the ground, through the process of weathering. Carbon dioxide is slightly acidic and as it reacts with rocks and soil, it converts into other chemical forms. The only problem in putting nature to work on carbon sequestration is that the process takes too long by human standards. In order to help limit the amount of carbon dioxide in the atmosphere, some geologists are looking to speed the weathering process up through industrial means — converting carbon dioxide into carbonate rocks.“We end up making rocks,” says Klaus <span class="blsp-spelling-error" id="SPELLING_ERROR_4">Lackner</span> of the Earth Engineering Center at Columbia University. But they have to start with rocks first. To do so, they use magnesium silicates, a class of <span class="blsp-spelling-error" id="SPELLING_ERROR_5">peridotite</span> rocks that include serpentine and olivine. Exposing magnesium silicate to an aqueous solution of the slightly acidic carbon dioxide forms carbonate and silicate, such as sand. Presto-<span class="blsp-spelling-error" id="SPELLING_ERROR_6">chango</span>, the carbon dioxide is gone and new carbonates and silicates have replaced the original rock. And the process is exothermic, producing heat. “So its thermodynamics are downhill, it happens spontaneously,” <span class="blsp-spelling-error" id="SPELLING_ERROR_7">Lackner</span> explains. This is why weathering in nature also occurs over time. So why <span class="blsp-spelling-error" id="SPELLING_ERROR_8">aren</span>’t we mass-producing carbonate rocks with our abundance of carbon dioxide? Again, time is the limiting factor. The world has an abundance of magnesium silicate rocks, but reacting those rocks with only carbon dioxide is a slow process. “We are trying to take the process and accelerate it for an industrial setting,” <span class="blsp-spelling-error" id="SPELLING_ERROR_9">Lackner</span> says. In order to speed the reaction up, a stronger acid is also needed and, in some cases, additional heat. The Albany Research Center in Oregon, and Ohio State University, are both working on building cost-efficient methods. Ultimately, achieving large-scale sequestration will mean building power plants at magnesium silicate mines around the world that would convert the olivine and serpentine into carbonates. The newly formed carbonates would then be put back into the mines for permanent disposal.The Ohio group is fine-tuning their high-pressure, high-temperature, three-phase fluidized bed reactor, an apparatus that uses a mixture of acids to dissolve serpentine in an aqueous solution of carbon dioxide. “In 30 minutes we can convert about 25 percent of solid magnesium silicate to carbonate at 1,000 [pounds per square inch] pressure and 80 degrees Celsius,” says Ah-<span class="blsp-spelling-error" id="SPELLING_ERROR_10">Hyung</span> Alissa Park, lead author on a presentation about this technique at the American Institute of Chemical Engineers in November. “At higher temperatures and pressures the conversion rate goes up.” Still, the science is in its infancy, <span class="blsp-spelling-error" id="SPELLING_ERROR_11">Lackner</span> says. “It is an example of where we learn more the cleverer and better we will get.”</em><br /><br />So there we have it. My mind is open on this subject. I still think it’s quite interesting… although I do question the economics of ameliorating the consequences of coal use through mining and crushing five or six times as much rock as the coal we burn. If there is a way around that issue, someone please let us know.<br /><br />One question which has occurred to me is just how powerfully is the carbon bound up in the resulting mineral? If it is only bound lightly, could we use these carbonates to recycle the carbon back into liquid fuel using power from nuclear reactors? While the economics of using this technique to continue burning coal might not necessarily work, perhaps it has other uses in an advanced nuclear economy.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com6tag:blogger.com,1999:blog-5176706508860724063.post-56357048433738111742008-10-26T14:44:00.004+11:002008-10-26T17:08:23.388+11:00Further Considerations of the Complexity Ethic.Thinking back on the time when my friend first announced the complexity ethic to me, I know he was reading a number of books on subjects such as ecology, sustainability, energy policy, peak oil and general history. I’ve asked him if he recalls any particular material which influenced him to consider complexity from an ethical perspective. The following is the list which he came up with:<br /><br />Emergence: The connected lives of ants, brains, cities and software.<br />Steven Johnson, Touchstone Press, 2001.<br /><br />The Hidden Connections: A science for sustainable living.<br />Fritjof Kapra, Harper-Collins, 2002<br /><br />Sync: The emerging science of spontaneous order.<br />Steven Strogatz, Theia, 2003.<br /><br />Ubiquity: The science of history… or why the world is simpler than we think.<br />Mark Buchanan, Crown Publishers, 2000.<br /><br />Our discussions on these and other topics formed a kind of loose dialogue (occasionally broken off for long periods) which my friend and I have been having on the prospects for humanity for many years now.<br /><br />Academia’s interest in the topic of complexity goes back much further than the turn of the century, of course. Consider the following:<br /><br /><em>“Organized complexity here means that the character of the structures showing it depends not only on the properties of the individual elements of which they are composed, but also on the manner in which the individual elements are connected with each other. In the explanation of the working of such structures we can for this reason not replace the information about the individual elements by statistical information, but require full information about each element if from our theory we are to derive specific predictions about individual events. Without such specific information about the individual elements we shall be confined to what on another occasion I have called mere pattern predictions- predictions of some of the general attributes of the structures that will form themselves, but not containing specific statements about the individual elements of which the structures will be made up.<br /><br />This is particularly true of our theories accounting for the determination of the systems of relative prices and wages that will form themselves on a well-functioning market. Into the determination of these prices and wages there will enter the effects of particular information possessed by every one of the participants in the market process- a sum of facts which in their totality cannot be known to the scientific observer, or to any other single brain. It is indeed the source of the superiority of the market order, and the reason why, when it is not suppressed by the powers of government, it regularly displaces other types of order, that in the resulting allocation of resources more of the knowledge of particular facts will be utilized which exists only dispersed among uncounted persons, than any one person can possess.”<br /></em><br />-F.A. Hayek, “The Pretence of Knowledge’ (1974 Nobel Lecture).<br /><br />And this:<br /><br /><em>“…we have both observational and theoretical reasons to believe that the general principle holds: Complexity is an important factor in producing stability. Complex communities, such as the deciduous forests that cover much of the eastern United States, persist year after year if man does not interfere with them… a cornfield, which is a man-made stand of a single kind of grass, has little natural stability and is subject to instant ruin if it is not constantly managed by man.”</em><br /><br />-P.R. Ehrlich and A.H. Ehrlich, Population, Resources and environment. (Freeman, San Francisco, 1970) p.159.<br /><br />Friedrich Hayek and Paul Ehrlich seem to be saying very similar things here, although in different contexts. Having those two individuals in agreement with each other is surely remarkable enough to flag that something interesting and unusual is going on with this topic.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com0tag:blogger.com,1999:blog-5176706508860724063.post-90573884182216860912008-10-18T20:26:00.000+11:002008-10-18T21:24:09.835+11:00The Ethics of Complexity.About half-a-decade ago I was helping a friend in his garden when he announced to me his new ethical framework. I was involved in that instant in ripping weeds out of the garden bed, a task which my friend was constrained from by repeated attacks of gout, and for which he paid me richly in beer and bourbon.<br /><br />“I’ve just come up with a new ethical system.” He said. “It only has one commandment: Thou shalt not reduce complexity!” Later on he decided that particular expression of the core concept was too negative, and proposed “Foster complexity!” as a more positive formulation.<br /><br />I paused in my labours for a bit to consider this idea. I thought at the time that it had considerable merit, and I still do. When we consider the central ethical tenets of the major philosophical and religious systems, we can see that pretty much all of them are expressing the same basic idea in different ways, and with different emphases, but what is that core idea? Although it is perhaps obscured in some interpretations, they all seem to attempt to provide a cultural framework for the maximisation of complexity in one form or another.<br /><br />If someone is murdered, the complexity of the universe is diminished. If a forest burns up, complexity is diminished. If a peasant-society’s crops fail due to drought, complexity is greatly reduced. If a city is levelled by a nuclear bomb, complexity is greatly reduced. Most, if not all undesirable things and situations seem to involve a reduction in complexity, while most if not all desirable things appear to be an enhancement of complexity in one form or another.<br /><br />One thing that greatly interested me about this notion is the possibility that complexity can be mathematically defined and quantified. If we reach that capability, I suspect that many complex ethical questions are susceptible to a mathematical solution… such as the relative balance of interest between environmental and economic concerns.<br /><br />Well that’s all well and good, but what does it have to do with nuclear power?<br /><br />Perhaps when considering the merits and downsides to various energy solutions, we might ask ourselves how their implementation will impact the net complexity of our environment and economy. Does the proposed technology have a severe impact on the net complexity of the living world? Does it allow for the growth of complex, intricate social and economic forms in our society, or does it constrain them through impoverishment and resource diversion? Over my next few posts I might consider some of these issues in relation to nuclear power and its competitors.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com13tag:blogger.com,1999:blog-5176706508860724063.post-36344774944746014552008-10-16T21:58:00.001+11:002008-11-18T03:22:44.476+11:00About this blog.We exist in a sea of electromagnetic force, and are for the most part utterly subject to its dictates. One other force makes itself blatantly known in the course of our mundane activities, namely gravitation, but electromagnetism packs far more power in its punch. It takes a mass the magnitude of Earth to make us weigh ten Newtons to the kilogram, but with a simple rearrangement in the structure of a vanishingly, ridiculously tiny portion of Earth’s mass, we can override the gravitational force of this entire planet, and stand on two feet (by burning sugar in our cells) … or fly to the other side of it in a 747 (by burning hydrocarbons in a jet engine).<br /><br />The sheer divide of magnitude between the two phenomena is obscured in our minds by the fact that the only kind of object great enough for us to sensibly experience the power of the lesser force is a world. The world is our universe. How can a basic overall fact of life which everyone experiences (stuff falls down) have any relation to the growth of plants, or the warmth of the hearth on a winter’s eve?<br /><br />The proportional difference between the amount of mass needed to make a sensible impact for the strong nuclear force and the electromagnetic force is nowhere near as great as that between the electromagnetic and gravitational force, but it is huge nonetheless. Once again we are faced with a sharp fracturing of our experience, but this time in a direction which contradicts our innate sense of cause and effect to a much greater degree than the considerations leading us to appreciate the weakness of gravity. This time we move in the direction of far greater power, and the realm of graphic, iconic consequence.<br /><br />The images of the early nuclear age have a certain amount of baggage which we need to move beyond to make informed choices for the future. This blog is my humble attempt to encourage people to make that move.Finrodhttp://www.blogger.com/profile/02447747229391757964noreply@blogger.com4