Nuclear reactions and their applications
You can find uranium-235 in nature, but only in uranium-238. To split this uranium-235 from uranium-238 is very expensive, because their chemical properties are the same so it is not possible to split them in a chemical way. A nuclear bomb like this can have an explosion force of 20 kilotons (20000 tons). This means that an explosion of such a bomb is as effective as the explosion of 20 kilotons of TNT. Hydrogen bombs can reach an explosion force of 20 megatons (20 million tons). This bombs are also knows as three-phase fuzes. The fission like in a nuclear bomb is only the first phase. In the second phase there is a fusion between deuterium and tritium. The temperature in the second phase behaves 200 to 300 million degrees Celsius (much hotter than the core of the sun). The third phase is the fission of uranium-238 that is of the outer side of the bomb. Under these conditions, the fission of uranium-238 is possible. The principle of power plants is the same like in nuclear bombs, but without using TNT. The reason why nuclear power plants do not explodes is that there are control rods to control the number of the neutrons in the reactor. This is a controlled nuclear chain reaction in the opposite of the uncontrolled nuclear chain reaction in nuclear bombs. The nuclear power plants in the future will be fusion reactors that do not crack heavy atomic nucleus, but fuses light atomic nucleus. Fusion is possible today but energy, which you need for a fusion, is higher than the energy you get and this is not the sense of nuclear fusions. With fusion, the last elements of the "Periodic table of the elements" have been created, because they are not on earth. In 1999 a few physicists thought that they have discovered the element 118 but two years later in 2001 they said that it was a mistake, so element 114 is the last know element. There is fusion also happening in the stars. In our sun, it is the proton cycle which you can find on the website of astronomy and astrophysics. Now I will give an answer why we get energy from this nuclear reaction. We must begin with Einstein's famous formula: E=mc2 (E stands for energy, m stands for mass and c stands for the speed of light in the vacuum). This formula makes it possible transform mass into energy. Atomic nucleus has got different binding energy. The binding energy is the energy that holds the nucleons together. Because of this fact there is in every atomic nucleus a mass defect. A free proton and a free neutrons weighs more than deuterium (heavy hydrogen, consists of one proton and one neutron). Iron has got the highest binding energy and stands in the middle of the "Periodic table of the elements". When somebody goes closer to this middle with fissions or fusions a part will be transformed into energy. Nuclear chemistry Nuclear chemistry deals with radioactivity, nuclear processes and nuclear properties. It is the chemistry of radioactive elements such as the actinides, radium and radon together with the chemistry associated with equipment (such as nuclear reactors), which are designed to perform nuclear processes. This includes the corrosion of surfaces and the behaviour under conditions of both normal and abnormal operation (such as during an accident). An important area is the behaviour of objects and materials after being placed into a waste store or otherwise disposed of. The radiation chemistry controls much of radiation biology as radiation has an effect on living things at the molecular scale, to explain it another way the radiation alters the biochemicals within an organism, the alteration of the biomolecules then changes the chemistry which occurs within the organism, this change in biochemistry then can lead to a biological outcome. As a result nuclear chemistry greatly assists the understanding of medical treatments and has enabled these treatments to improve. Nuclear safety Nuclear safety includes the actions taken to prevent nuclear and radiation accidents or to limit their consequences. This covers nuclear power plants as well as all other nuclear facilities, the transportation of nuclear materials, the use and storage of nuclear materials for medical, power, industry, and military uses. In addition, there are safety issues involved in products created with radioactive materials. Some of the products are legacy ones (such as watch faces), others, like smoke detectors, are still being produced. Nuclear weapon safety, as well as the safety of military research involving nuclear materials, is generally handled by separate agencies than civilian safety, for various reasons, including secrecy. Atomic nucleus The atomic nucleus has protons with positive charge, and neutrons that are electrically neutral. The protons and neutrons are kept together by a new kind of force that we do not encounter in our everyday life, the so-called strong force. It is called so because it is so strong that it can keep the atomic nucleus together even though the protons are repelled by each other due to the electromagnetic force. With the help of only three building blocks, the proton, the neutron, and the electron, as well as their electromagnetic and strong interactions we can form all the atoms in the periodic system. Protons and neutrons are equally affected by the strong force, but not all particles are. One such example is the electron. The particles that are affected by the strong force are called hadrons and today we know of several hundred different kinds of hadrons. Today we also know that the hadrons are not fundamental particles, but instead they are built up of quarks. The first proofs that the proton has an inner structure came in the end of the 1960's from an experiment done at Stanford Linear Accelerator Center in the USA. By irradiating protons in a fixed target with high energy electrons and studying how the electrons were scattered one concluded that protons have an inner structure, the quarks. Already earlier one had hints that protons and neutrons have an inner structure based on their magnetic dipole moments that do not at all agree with what one expects from a point like particle. Education and Training As with any engineering discipline, college preparation should include mathematics training through the beginnings of calculus, as well as introductory courses in physics and chemistry. Undergraduate coursework should begin with a foundation in mechanics and dynamics of particle motion, thermodynamics, introductory computer programming, college level physics and chemistry, and a rigorous training in mathematics through differential equations. Midway through undergraduate training a nuclear engineer must choose a specialization within his or her field that he or she will further study. Further coursework in a nuclear engineering program includes but is not limited to fluid mechanics, reactor physics, quantum mechanics, thermal hydraulics, linear circuits, radiation effects, and neutron transport. Specialization in fission includes the study of nuclear reactors, fission systems, and nuclear power plants; the primary teachings deal with neutronics and thermal-hydraulics for nuclear generated electricity. A firm foundation in thermodynamics and fluid mechanics in addition to hydrodynamics is a must. Specialization in nuclear fusion includes electrodynamics and plasmas. This area is very much research oriented and training often terminates with a graduate level degree. Specialization in nuclear medicine includes courses dealing with doses and absorption of radiation in bodily tissues. Those who get competency in this area usually move into the medical field. Many nuclear engineers in this specialization go on to become board licensed medical physicists or go to medical school and become a radiation oncologist. Research is also a common choice for graduates. Professional Career Areas Nuclear Fission Nuclear Fission is the disintegration of a fissionable atom nucleus into two different elements nucleus. An approximate number of ~2.4 neutrons are scattered around per fission. There are two types of nuclear fission. 1-Fast Fission 2-Thermal fission. Generally, thermal fission is used in commercial reactors, if we disregard the Fast Breeder Type of Nuclear Reactors. The United States gets about 20% of its electricity from nuclear power. This is a massive industry and keeping the supply of nuclear engineers plentiful will ensure its stability. Nuclear engineers in this field generally work, directly or indirectly, in the nuclear power industry or for government labs. Current research in industry is directed at producing economical, proliferation resistant reactor designs with passive safety features. Although government labs research the same areas as industry, they also study a myriad of other issues such as: nuclear fuels and nuclear fuel cycles, advanced reactor designs, and nuclear weapon design and maintenance. A principal pipeline for trained personnel for US reactor facilities is the Navy Nuclear Power Program. Nuclear Fusion and Plasma Physics Research areas in nuclear fusion and plasma physics include high-temperature, radiation-resistant materials, and plasma dynamics. Internationally, research is currently directed at building a prototype tokamak called ITER. The research at ITER will primarily focus on instabilities and diverter design refinement. Researchers in the USA are also building an inertial confinement experiment called the National Ignition Facility or NIF. NIF will be used to refine neutron transport calculations for the US stockpile stewardship initiative. Nuclear Medicine An important field is nuclear medicine. From x-ray machines to MRI to PET,among many others, nuclear medicine provides most of modern medicine's diagnostic capability along with providing many treatment options. Nuclear Materials and Fuels Nuclear materials research focuses on two main subject areas, nuclear fuels and irradiation-induced modification of materials. Improvement of nuclear fuels is crucial for obtaining increased efficiency from nuclear reactors. Irradiation effects studies have many purposes, from studying structural changes to reactor components to studying nano-modification of metals and semiconductors using ion-beams or particle accelerators. Radiation Measurements and Imaging Nuclear engineers and radiological scientists are interested in the development of more advanced ionizing radiation measurement and detection systems, and using these to improve imaging technologies. This includes detector design, fabrication and analysis, measurements of fundamental atomic and nuclear parameters, and radiation imaging systems, among other things. Nuclear Engineering Career Opportunities The median salaries annual earnings of mining and geological engineers, including mining safety engineers, were $61,770 in 2002. The middle 50 percent earned between $48,250 and $77,160. The lowest 10 percent earned less than $36,720, and the highest 10 percent earned more than $93,660. Nuclear engineers were employed in around 16,000 jobs. Half of these were in the utilities sector, one-quarter were employed by professional, scientific, and technical services firms, and 14 percent were hired by the Federal Government. A large number of nuclear engineers employed by the Federal Government work as civilians in the U.S. Navy, while the remaining were employed by the U.S. Department of Energy. It is predicted that profitable job opportunities are available for nuclear engineers because the small quantity of nuclear engineering graduates are expected to equal the number of job openings. Due to the fact that nuclear engineering is a relatively small occupation, the predicted increase in employment will open some avenues for jobs but job opportunities will mainly be a result of retirement and transfers of existing engineers. Nuclear engineering organizations
The American Nuclear Society (ANS) It is an international, not-for-profit 501(c)(3) scientific and educational organization consisting of approximately 11,000 engineers, scientists, educators, students, and others with nuclear-related interests. Approximately 900 members live outside the United States in 40 countries. There are 51 U.S. and nine non-U.S. local sections, 24 nuclear plant branches and 34 student sections. ANS members represent more than 1,600 corporations, educational institutions, and government agencies. On December 11, 1954,the Society was established. It's been a leader in the development of nuclear consensus standards since 1958. Its main objective is to promote the advancement of science and engineering relating to the atomic nucleus. Other purposes are to integrate the many nuclear science and technology disciplines, encourage research, establish scholarships, disseminate information through publications and journals, inform the public about nuclear-related activities, hold meetings devoted to scientific and technical papers, and cooperate with educational institutions and government agencies The International Atomic Energy Agency (IAEA) It seeks to promote the peaceful use of nuclear energy and to inhibit its use for military purposes. Media often refer to the IAEA as "the UN's Nuclear Watchdog". While this describes one of the Agency's roles, it is by no means the only one. The IAEA has its headquarters in Vienna, Austria. Two "Regional Safeguards Offices" are located in Toronto, Canada; and Tokyo, Japan. The IAEA has two liaison offices, located in New York, USA; and Geneva, Switzerland. In addition, it has laboratories in Seibersdorf and Vienna, Austria; Monaco; and Trieste, Italy. Institution of Nuclear Engineers The Institution of Nuclear Engineers is a learned society and the only qualifying body concerned solely with the advancement of nuclear engineering technology and their allied field. The Institution acts as consultant to government, professional and statutory bodies in the formulation of decisions affecting the nuclear industry and is recognized as the representative of the profession. The Institution is a Nominated Body of the Engineering Council. As such, it is able to register suitably qualified nuclear engineers as Chartered or Incorporated Engineers and also registers Engineering Technicians. Membership of the Institution represents the best of a highly qualified, innovative profession, internationally recognized and respected. The governing council is drawn from all sectors of the industry and associated academic institutions. |
