Nuclear Power Versus Renewable Energy

Nuclear Power Versus renewable Energy single of the biggest problems that we face in todays modern ply famished times is the decision on a single extraction of exponent. As we continue to consume as a society we argon very(prenominal) quickly burning through our supplies of fogey elicits to the point at which in a couple of decades we depart give way all in all(prenominal) just fagged existing supplies.It is for this reason that decisions need to be made on what witnesser go forth generate future genesiss electrical muscularity. The future of slide unshakableener production leave alone lie with the criteria set out by fogey sack naught production and how easily they fit these criteria. Any new give notice book of facts will have to be readily available and provide a constant supply of ability it will need to be meretricious and safe to bring about the same or fewer emissions than that of fossil fuels, although with todays latest eco standards the later wi ll probably need to be true. iodin limited credit of aught seems the logical plectrum for the main reliever for fossil fuels and that is atomic origin, but how do other more than renewable sources of qualification compargon to nuclear might? In 2002 it was reported by an MIT submit that nuclear force out supplied 17% of the solid grounds electricity consumption 1 and if this is comp argond to renewable sources overmuch(prenominal) as finish up power, geothermal and biomass generators which accounts for just 19% as c beful in 2008 2. The aim of this paper is to compargon and contrast the viability of different free cogency sources for the future.What is nuclear power?Nuclear power in its current republic is the authorisationled nuclear nuclear fission of radioactive material for the genesis of electricity.Nuclear power works uracil primarily as a fissible material, the first recourse issues come from obtaining a source of atomic fig 92 that is viable to manipulation for nothing generation. Uranium slide bys course in a escalate ore form, comprised of 99.3% U238 and 0.7% U235 3. Uranium 238 is not a fitted isotope for fission, infact in its inborn ore it holds the uranium from sustaining whatsoever sort of nuclear reply. This fire be explained by the energy of absorbed neutrons in the nuclear material, U235 will undergo fission at all energies of neutrons, but U238 will not. To cross this problem, uranium ore needs to be enriched with a higher(prenominal) percentage of U235 (usually so that U235 comprises 3% to 5% of the ore 3). The enrichment process introduces condom issues that are not stupefy in other forms of energy production, the process produces uranium hexafluoride that is a passing toxic chemical that is difficult to store callable to its corrosive nature. The main waste product is depleted uranium that the radioactive waste from extracting U235 from natural Uranium ore. There has been much controversy over Depleted uraniums use as a weapon and its difficulty in organism stored due to its radioactive nature, current estimates put global stockpiles of depleted uranium at 1.5 million tonnes 3.The generation of power from radioactive sources makes use of a compound nuclear answer. Neutrons are absorbed by enriched uranium, usually a uranium ore composed of mainly U235, which forms an excited compound meat. A compound nucleus will be inherently un unchangeable and result in the fission of the excited compound nucleus and emission of two new nuclei and neutrons. throw 1 illustrates a possible nuclear reaction inside a nuclear reactorFigure 1- Example of nuclear reaction. n+U235 U*236 Xe139 +Sr95 + 2nAs hindquarters be seen from figure 1 the interpreter fission reactions lease a single neutron to induce fission of U235 but the terminal products of the reaction include 2 neutrons which allows the reaction to effect self perpetuating, this neutron feeding process is known as a cha in reaction. This chain reaction will plainly occur in enriched uranium.Nuclear power is generated victimisation two different types of reactor that some(prenominal) have their merits and faults with regard to safetyThe degenerate reactor is a reactor based on an meet mix of Uranium 235 and 238 that can sustain the chain reaction necessitate to generate energy. prompt neutrons, hence the name, sustain the reaction, in the case of the close reactor neutrons interact with U238 whicch forms a nucleaus that does not under go fission but forms plutonium 239 instead. Although Pu 239 is able to undergo fission, it does not do so at the speed required to sustain the chain reaction and infact some of it becomes unused waste in the form of spent fuel. The firm reactor is designed to navigate around this by employ the fast neutrons to produce more fissile Pu239 than spent Pu239 by not using a moderator to slow neutrons down this reduces the problem of producing lots of unused fuel a s waste. Because this type of reactor does not use a moderator to control neutrons and due to the exceedingly fissile material in the reactor core, it does require an efficient cooling system which does introduce certain safety issues. Fast reactors require a liquid sodium coolant, chosen due to its extremely conductive nature, to remove horniness from the core. The use of sodium though has its associated risks because its highly reactive and becomes corrosive when reacting with air which is obviously a problem when surround a radioactive core.Thermal reactors use enriched uranium to produce energy instead of an equal mix and the enrichment produces the waste products as discussed earlier. Un standardised fast reactors which do not use moderators thermal reactors, and the ones in question use a moderator and coolant. In the case of Pressurised water system reactors and boiling water reactors they both use water as a coolant and moderator due to waters inherent property that it is a good neutron absorber. The water based thermal reactors are one of the most widely used nuclear reactors due to the availableness and safety of the coolant and moderator. There are contamination risks with the boiling water reactor, as water is pumped through the reactor and boils it will pick up fragments of radioactive contaminants which could be released into the automated teller via the cooling predominates.For note the worlds commodiousst nuclear power gear up uses 7 different boiling water reactors to generate electricity and is capable of generating a total of 8,212MW and a typical fossil fuel turbine is capable of generating 1000MW so a typical fossil fuel specify can be analyzed to outputting a similar core of energy to that of a nuclear power meant 3b.Safety of Nuclear PowerWith the ebullition of the Chernobyl nuclear power plant and the recent persistdown risks of the Fukushima reactors safety tints are always inherent when discussing nuclear power.Meltdowns are often a bombinate word when associated with nuclear power plants and is often the biggest safety concern when considering nuclear power, but what exactly is a nuclear meltdown? A nuclear meltdown is not as serious as the word suggests or as the world media have suggested. A meltdown will occur when there is more heat inside the reactor core than that beingness removed by any coolant mechanism that are put in place. If this does happen then the nuclear fuel will literally melt causing it to melt through the reactor. This will result in footing to the reactor core and a possibility of the fuel escaping the reactor, but nuclear reactors are contained within a containment structure that is designed to prevent any radioactive material from contaminating the atmosphere and allowing coolant to be pumped into the structure. This only becomes an issue when the containment structure is damaged as was the case during the Fukushima earthquakes, with the exception of natural disasters m odern nuclear power plants are designed with the up most safety in mind and have many different precautions in place to prevent and characterization and risk to the general public.Control rods are one of the beat out designed safety features within a nuclear reactor, they are designed to avoid any rapid increase in reactor core temperatures. When fuel temperatures rise to a temperature at which coolant will be contaminated and need to be ejected, the control rod safety mechanism kicks in. They are designed to slow the neutron flux with in the reactor, much like the moderator does, and hence slow down the rate of energy generation so that coolant can carry heat away without the risk of contamination. Systems are in place so that this precaution is activated immediately when any reactor threat is detected. This safety measure reduces the risk of any radioactive material being ejected via cooling systems.In fact studies suggest that exposure to radioactive sources due to nuclear powe r beams and nuclear fuel plants are less than 0.1% of human annual exposure to radiation, this can be seen from figure 1. So although there is a high chance of radioactive contamination the safety mechanism that are in place prevent this risks from occurring and keeping exposure down to a minimum.Figure 2- Figures showing annual sources of radiation exposure 4With this in mind although there are danger risks when considering nuclear fuel as a replacement for fossil fuels, the number of design features installed to prevent this is more than adequate to ensure the safety of the applied science.Proliferation concerns integrity concern with Nuclear power is not the safety risks of the power station or the waste they produce but instead that enrichment facilities can produce Uranium that is enriched for use in nuclear weapons. This is much a concern in the developing world where governments are not as stable and it would not take long for a fuel enrichment facility to come forward p roducing weapons grade uranium.renewable energy sourcesSo far we have looked at some of the pros and cons of nuclear power and it seems like a viable alternate to fossil fuels, but technological advances have allowed renewable energy sources to become a viable option for industrial production of energy. Renewable sources of energy cant produce energy on the scales that nuclear power plants can but they do not suffer from the contamination complications that nuclear power does.solar powerSolar power exploits natures biggest source of energy the sun, which outputs a massive 3.841026W 5 of which we receive 1.741017 W or 1.366kW/m2 6. This is a considerable amount of energy to exploit and an obvious choice for renewable energy because the sun is expected to remain in the riff for the next four and a half billion years. This seemingly amend candidate for energy production seems comparatively unused as solar power accounts for just 0.9% 7 of worlds energy production. one and only(a) of the main issues with solar technology is the photovoltaic cell, this being the standard solar panel technology, it has a relatively low efficiency and as a result the amount of energy outputted does not represent the full potential from the energy put in, too with the sun being an intermittent energy source, the only way photovoltaic cells can produce energy at nights is with the use of large banks of batteries, which are expensive and an environmental hazard.There are seemingly new technologies front crawl into the solar market, much simpler than the photovoltaic cell and much more efficient. One such technology is the solar tower. The solar tower uses a large field of heliostats which are mirrors that track the sun to focus the suns light on a single point which is a central tower. The central tower uses the heat supplied to drive a locomote turbine capable of generating between 10 and 100 MW (dependant on the number of mirrors), for example the PS10 solar power plant in Spa in uses 624 heliostats to generate 11MW and is appease being constructed8. This may seem like a small amount of energy but a large area solar power tower could provide much more energy, by increasing the area of the plant, by increasing the number of heliostats. One such project is currently under way in the Mojave relinquish which covers 4000 acres and aims to generate enough electricity to power the city of San Francisco 9. unlike Photovoltaic cells solar power towers have the capability of producing energy at night. When the suns energy is focused on the central tower some of the heat which is used to drive the turbines is also used to heat salts to molten temperatures in bare(a) of 200 C, molten salts can keep their temperature very well if insulated properly, and when required can be pumped through the turbine to generate steam to generate electricity 10.Given enough time Solar power could become a replacement for fossil fuel energy production, but in the meantime it suffe rs from high initial costs, a large carbon copy footprint and a lack of backing. Currently Spain appears to be the pioneers of this technology and have already constructed numerous solar power towers including PS10 as discussed earlier. summit powerOne by-product of the suns energy that has yet to be mentioned is that it supplies energy into the atmosphere causing temperature and pressure differences, this produces a bulk movement of air molecules resulting in the wind. The wind is a much more exploited energy source compared to solar power, with wind power producing 2.5% of the worlds electricity11.Wind power generates electricity in a very similar manner to a conventional power generator, but instead of using water as a nomadic to turn a turbine, the wind is the fluid that turns the turbine. Although there is a earthshaking amount of power available in the wind not all of it can be extracted and a theoretical limit has been calculated for the amount of energy that can be 12. Th is limit means that 59.3% of energy in the wind can be used for energy generation. In realism much less than this is extracted because wind is not a uniform median(a) and as such suffers from intermittency issues similar to solar power, in that wind is not a constantly accessible resource.Hydroelectric PowerOne already established form of renewable energy is Hydroelectricity, the generation of energy using the conversion of gravitational potential energy of falling water through a turbine. Its currently the 4th largest form of power generation stooge coal, gas and nuclear power producing 20% of the worlds current electricity demands 13. Interestingly though Hydroelectricity has been exploited in the 1st world, with almost all possible sites being developed for hydroelectricity, its only in the developing world where hydroelectricity could be utilized to improve renewable energy generation, this would explain why it is the 4th largest energy provider 13.Unlike wind power and solar power, hydroelectric power does not suffer from intermittency issues. The idea behind a hydroelectric dam is that it uses the water at a higher gravitational potential to fall through a turbine generating electricity. When there is a smaller demand for electricity the flow rate can be reduced and the reservoir can be used to store excess water, this provides the dam with water on demand, which is a unique feature of hydroelectric power.Three gorges dam in china is a fantastic example of a 21st century hydroelectric plant, for reference it is capable of producing 22500MW 14 this is great than 100 times the amount of energy produced by a solar power tower, and 5 times more energy than the largest nuclear power stations, so obviously hydroelectric dams are useful and utilizable replacement for fossil fuels.Hydroelectricity does have its environmental faults, and is probably the most hazardous of the renewable power sources. In localise to construct a hydroelectric plan a large enoug h volume of water is required with a big enough drop for potential energy conversion to kisser building a hydroelectric plant. To do this a river must be dammed which upriver will flood a large area of land, this causes huge amounts of destruction to natural habitats, downriver there is a chance that beverage water is contaminated which has obvious human impacts.Conclusion on energy typesWe have discussed the different aspects of nuclear power and many different types of renewable energy sources. It is my opinion that despite certain renewable already being established they have still not reached their potential to replace fossil fuels, especially with certain intermittent issues and as a result are not ready to replace fossil fuels. On the other hand, eon renewable sources develop into a more viable energy source nuclear power is ready to replace fossil fuels in the interim.If we compare energy production it would appear as if hydroelectric dams are the best option, but as discu ssed all sites in the developed world have been exploited and for comparison nuclear power stations are still being built as many possible sites still exist. condescension its safety issues and the non-renewable nature of nuclear fuel, nuclear power is capable of producing a steady supply of power that will meet demands upon request. In populace there is no one replacement for fossil fuels, as a society we have created a huge dependence on them and it is waiver to require a mixture of different power sources in order to develop a secure energy future and as a result our future probably lies with renewable energies and nuclear energies working in conjunction with each other.References1. 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Zook D., County supervisor interested by Brightsource Mega Solar Project Impacts calls for a full review, Best Syndication News, 2011.10. Barth D., discipline of a High Temperature, Long-Shafted, Molten-Salt Pump for Power Tower Applications, Journal of Solar Energy Engineering, 200211. Ragheb M., Wind Power SystemsHarvesting the Wind, College of Engineering University of Illinois, 2011.12. Gijs A.M. van Kuik, The Lanchester-Betz-Joukowsky Limit, Wind Energy Journals, 2007, 10289-29113. Hydropower and the Worlds Energy Future, International energy agency publication, 2000, modify 2009.14. Fabian A., Taming the Yangtze, IET publications, 2009.