Wednesday, December 2, 2009

Nuclear power not sufficient enough?
World must cut down amount of energy gained from fossil fuels, mainly because of global warming problem caused by harmful CO2 emissions, and many people see nuclear energy as the ideal fuel capable to replace dominant fossil fuels. Scientists calculated how nuclear energy production should increase by more than 10 percent each year in period from 2010-2050 in order to satisfy all future energy demands and successfully replacefossil fuels. But is this possible and is this acceptable or not? According to a report published in Inderscience's International Journal of Nuclear Governance, Economy and Ecology this rather high growth rate demands greater improvement in nuclear power efficiency, otherwise each new power plant will simply cannibalize the energy produced by earlier nuclear power plants. There are many additional problems that still don't justify dominance that nuclear energy currently has against renewable energy projects and seems like the real solution.

Costs of building such high-power nuclear projects would be too big since it would require tremendous energy input just to build so many newnuclear power plants. Nuclear power plants are also producing lots of heat as byproduct and though today this is relatively small effect, with future nuclear projects of greater magnitude this would additionally warm up already warm Earth and cause even bigger impact to already serious global warming problem.Manynuclear energy proponents think that nuclear energy is emission free but as Physicist Joshua Pearce of Clarion University of Pennsylvania explained "each stage of the nuclear-fuel cycle including power plant construction, mining/milling uranium ores, fuel conversion, enrichment (or de-enrichment of nuclear weapons), fabrication, operation, decommissioning, and for short- and long-term waste disposal contribute to greenhouse gas emissions".
However he doesn't suggest abandoning nuclear power option and he considers much more efforts should be mainly done to improve nuclear power efficiency and this could be achieved by orienting to dominant use of only the highest-concentration ores, and switch to fuel enrichment based on gas centrifuge technology, which is much more energy-efficient than current gaseous diffusion methods.

However there are also encouraging results accomplished by researchers at the U.S. Department of Energy's Idaho National Laboratory as they managed to reach a burnup level of fuel in nuclear reactor of astonishing 9 percent, without any fuel failure which is already described as nuclear power achievement milestone, and could significantly improve nuclear power efficiency. Raising a burnup level of fuel in nuclear reactor is important from many different reasons: first and most important it reduces the amount of fuel needed to produce certain amount of energy, it also reduces the volume of used fuel that gets generated, which significantly improves efficiency of total nuclear reactor system. However this 9 percent achievement isn't looking to be final goal for this year as this team plans to achieve a 12-14 percent burnup later this year. A burnup is measure of the neutron irradiation of the fuel and higher burnup allows more of the fissile 235U and of the plutonium bred from the 238U to be utilized, reducing the uranium requirements of the fuel cycle and increasing its efficiency.

This basically means that nuclear energy with current efficiency levels isn't enough to substitute dominant fossil fuels in the next 40 years and that there needs to be much more research efforts, mainly to improve efficiency in order to make nuclear energy solution capable to replace fossil fuels. However with such optimistic results of projects like the one researchers at the U.S. Department of Energy's Idaho National Laboratory carried out, efficiency can be improved significantly, of course with enough given time and sufficient funding, andnuclear energy could turn out to be possible and efficient alternative to fossil fuels.

More about nuclear energy you can read here.

Nuclear power plant - Steam towers are generally the buildings that people
associate with nuclear power plants.

Nuclear energy

Nuclear energy advantages:
Nuclear technology is mature and safe
Nuclear technology produces high amount of energy
Nuclear energy is sustainable

Almost two billions of people across the globe don’t have access to electrical energy and this problem will become even worse since Earth's population is growing. Global relying on fossil fuels and huge hydro-electrics will remain trend at least to year 2020, but that won't be enough to satisfy constant and ever-growing humanity needs. As one of the possible solutions of this problem,nuclear energy isolates itself. In the last three decades nuclear energy has significant part in electrical energy production. Momentarily with the help of the nuclear energy, 16% of total world's electrical energy production is generated. Strong burst of nuclear energy can be related with its purity and almost non greenhouse gases' emission. Well constructed nuclear power plants showed to be reliable, safe, economically acceptable and ecologically benign. Till this date more than 9000 reactor-year work was accumulated, so necessary experience in using thenuclear energy was also summoned

Environment influence and radioactive waste

Consequences of Chernobyl’s nuclear disaster. Radioactive gasses got even at Germany and Italy.
Like every other process of energy production from non renewable sources, nuclear power plants are producing waste as well, in this case radioactive waste and hot water. Since nuclear power plants are not producing the carbon dioxide, its use isn't increasing greenhouse effect. Radioactive waste is generally divided in to a two main categories: low-radioactive and high-radioactive waste. Majority of nuclear waste is low-radioactive waste. Those are usually: junk, equipments, protective suits and others. That waste is contaminated with small level of radioactive dust or particles, and must be safely kept in order not to get in contact with outside materials.
Real problem concerning the nuclear power plants is remain of the used fuel which is high-radioactive waste and must be stored in special pools (water freezes nuclear fuels acting as radiation shield) or in dry containers. Older, less radioactive fuel is stored in dry warehouses where is sealed in special containers made of a ferro concrete.

Nuclear power plants, despite being harmless for environment if everything is played by the rules, still present great threat to environment in possibility of nuclear disaster during irregular use. Two major nuclear disasters happened during the peacetime: Chernobyl and Island Three Miles. The biggest disaster that ever happened innuclear power plants was in Chernobyl, former SSSR, now Ukraine, on 26th April of 1986. Reactor number four exploded in power plant forming radioactive cloud which spread to a big part of Europe (picture). 27% of rescuers that went to a contaminated area became invalids and 200.000 of them went inside. During explosion, reactor's active zone was devastated, with 10 days and 10 nights lasting active level of disaster, accompanied with intensive release of radioactive elements. Radioactive elements' release was finally stopped after reactor had been stored in to a concrete "sarcophagus" in November of 1986. Total radioactivity under the "sarcophagus" surpasses two millions Curie.

Less damaging disaster for people and environment was the on Island Three Miles on 28th March of 1979 in Pennsylvania. There, because of the series of mistakes and security failures, one of the nuclear reactors overheated and partly dissolved, which resulted with smaller emission of radioactive substances in to an atmosphere. For time being, no harmful consequences of that radiation were noticed on the people, but that event had great influence to conception ofnuclear energy safety. In days that followed, there was large interest of media for this accident and nuclear energy demonstrators have finally gotten good reason for huge anti-nuclear campaign in the media. That campaign got its additional side effect in media because of the movie "China Syndrome" which started showing in cinemas just couple of weeks before the Island Three Miles' accident. In that movie, because of the series of safety failures nuclear reactor was almost dissolved, so even today nuclear reactor's melting is colloquially called "China Syndrome". All those happenings have not only convinced US government to increase nuclear installments' safety, but also to decrease the number of newly buildnuclear power plants.

Working principle

Procedure of releasing the nuclear energy. Uncontrolled process is called atomic bomb, and controlled process is a nuclear reactor.
Nuclear power plants are using as a fuel isotope of uranium U-235 which is very suitable for fission. In nature can be found uranium with more than 99% U-238 and only about 0.7% U-235. While U-238 is absorbing fast neutrons, U-235 on the other hand, when bombarded with slow neutrons degrades itself to very radioactive products offission , releasing in this process more fast neutrons (process). Deceleration of these fast neutrons when crashing with molecules of heavy water, which is heating itself in process, makes the nuclear chain reaction possible. Released heat is in fact this desirable energy. In nuclear reactors this process happens all the time in strictly controlled conditions (couple of moments in Chernobyl excluded). Atomic bomb is the result of deliberately caused enormous concentration of free neutrons which are then crashing withfission 's sensible atoms achieving uncontrolled energy explosion in the process. Although there's a significant number of Uranium in nature (hundred times more than silver) U-235 isotopes is very rare. Because of that uranium enrichment procedure becomes necessary. In final, useable faze, nuclear fuel will have a form of two and the half centimeter’s long tablets. One this tablet will be enough to give approximately same amount of energy as one ton of coal. Energy released when bombarding uranium with neutrons is used for the water heating. That water (steam) is then starting generator, and after that it's necessary to cool the water off and put it back to a reactor. To succeed in this, it's necessary to maintain constant and big fluidity of the water around the core of the reactor.

Countries' use of nuclear energy

Country that has the largest share of its electrical energy manufactured in nuclear power plants is France with 75%. Lithuania follows with 73%, and then Belgium with 58%, Bulgaria, Slovakia and Sweden with 47%, Ukraine with 44%, and Republic of Korea with 43%. Ten countries more have more than 25% of its totalelectrical energy produced in nuclear power plants. US is producing 19.8% of its electrical energy in nuclear power plants, but because of the high production range they are having the biggest share in the total electrical energy produced in nuclear power plants with 28%. France is second with 18%, and Japan third with 12%.

With the rising number of countries having nuclear power plants, risk that fuel from nuclear power plants will get in the hands of individuals that won't use it for peaceful intentions increased as well. Lately terrorism is being very alluring and terrorists with nuclear technology in their dispose could cause huge nuclear disaster. Politicians and scientists must take certain measures to protect us from this malicious use ofnuclear energy . International organizations, specifically because of this problem imposed the safety rules for 140 countries across the globe. Problems with storage of the nuclear fuel (and radioactive waste as well) is momentarily mostly expressed in poor countries, former members of SSSR

Consequences of Chernobyl’s nuclear disaster. Radioactive gasses got even at Germany and Italy

Nuclear energy facts

Nuclear energy facts. Nuclear energy is non-renewable energy source. Read some interesting facts about nuclear energy.

1Nuclear energy is energy that is released either by splitting atomic nuclei or by forcing the nuclei of atoms together.

2)Nuclear energy comes from mass-to-energy conversions that occur in the splitting of atoms. Albert Einstein’s famous mathematical formula E = mc2 explains this. The equation says: E [energy] equals m [mass] times c2 [c stands for the speed or velocity of light]. This means that it is mass multiplied by the square of the velocity of light.

3 )Nuclear energy is produced by a controlled nuclear chain reaction and creates heat—which is used to boil water, produce steam, and drive a steam turbine.

4)Nuclear power can come from the fission of uranium, plutonium or thorium or the fusion of hydrogen into helium. Today it is almost all uranium. The basic energy fact is that the fission of an atom of uranium produces 10 million times the energy produced by the combustion of an atom of carbon from coal.

5)Nuclear power plants need less fuel than ones which burn fossil fuels. One ton of uranium produces more energy than is produced by several million tons of coal or several million barrels of oil.

6)In France, nuclear power is the most widespread, supplying 80 percent of the country's electricity. A protest movement exists, called Sortir du Nucléaire, or "Get Out of Nuclear," but it appears to have made little headway.

7)Nuclear energy was first discovered accidentally by French physicist Henri Becquerel in 1896, when he found that photographic plates stored in the dark near uranium were blackened like X-ray plates, which had been just recently discovered at the time.

8)As of 2004, nuclear power provided 6.5% of the world's energy and 15.7% of the world's electricity, with the U.S., France, and Japan together accounting for 57% of nuclear generated electricity.

9)Nuclear energy (nuclear power) accounts for about 19 percent of the total electricity generated in the United States, an amount comparable to all the electricity used in California, Texas and New York, three most populous states.

10)There are 104 commercial nuclear generating units that are fully licensed by the U.S. Nuclear Regulatory Commission (NRC) to operate in the United States. Of these 104 reactors, 69 are categorized a pressurized water reactors (PWRs) totaling 65.100 net megawatts (electric) and 35 units are boiling water reactors (BWR) totaling 32.300 net megawatts (electric).

More nuclear energy facts:

On June 27, 1954, the USSRs Obninsk Nuclear Power Plant became the world's first nuclear power plant to generate electricity for a power grid, and produced around 5 megawatts electric power.

Russia has begun building floating nuclear power plants. The £100 million ($204.9 million, 2 billion руб) vessel, the Lomonosov, to be completed in 2010, is the first of seven plants that Moscow says will bring vital energy resources to remote Russian regions.

The International Nuclear Event Scale (INES), developed by the International Atomic Energy Agency (IAEA), is used to communicate the severity of nuclear accidents on a scale of 0 to 7.

The Chernobyl disaster in 1986 at the Chernobyl Nuclear Power Plant in the Ukrainian Soviet Socialist Republic (now Ukraine) was the worst nuclear accident in history and is the only event to receive an INES score of 7.

Nuclear energy is released by three exothermic processes:
Radioactive decay, where a proton or neutron in the radioactive nucleus decays spontaneously by emitting a particle
Fusion, two atomic nuclei fuse together to form a heavier nucleus
Fission, the breaking of heavy nucleus into two nuclei

The sun uses nuclear fusion of hydrogen atoms into helium atoms. This gives off heat and light and other radiation.

Nuclear energy is really making a comeback because nuclear energy has virtually none greenhouse gases emission and therefore isn't warming the planet and causing global warming like some other energy sources.

Building trust and increasing confidence in the use of nuclear energy are vital elements for public acceptance in democratic societies.

Nuclear energy is now very safe source of energy because safety measures are taken to its maximum so new Chernobyl is very unlikely to happen.

Compared to other non-carbon-based and carbon-neutral energy options, nuclear power plants require far less land area. For a 1000 MW plant, site requirements are estimated as follows: nuclear, 1-4 km2; solar or photovoltaic park, 20-50 km2; a wind field, 50-150 km2; and biomass, 4.000-6.000 km2.

Nuclear power is the only energy industry which takes full responsibility for all its wastes, and costs this into the product.

Nuclear energy would be dominant source of energy by now if it hadn't been Chernobyl and Three Miles island (nuclear disasters).

Nuclear energy can be very destroying. Hiroshima and Nagasaki are to date the only attacks with nuclear weapons in the history of warfare. The bombs killed as many as 140.000 people in Hiroshima and 80.000 in Nagasaki by the end of 1945, roughly half on the days of the bombings.

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