Ada Genavia
Jun 12, 2012
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Energy sustainability: Taking a step in the nuclear fusion direction

The interior of a Tokamak reactor used for research at MIT. The ITER reactor will have a similar design, but with numerous tehcnological improvements. Scientists considered Nuclear power a prominent energy alternative. It is more environmentally beneficial solution since it emits significantly less greenhouse gas during electricity generation than coal or other traditional power plants. Nuclear power is widely regarded as somewhat dangerous and potentially problematic. Nevertheless, it is also deemed as a manageable source of electricity. Additionally, it is not dependent on fossil fuels, such as coal or natural gas. This energy can be utilized to power homes, businesses and to supply electricity to large numbers of people. Nuclear fusion -- a reaction that occurs, for example, when two hydrogen atoms combine to produce one helium atom -- is one means of harnessing nuclear power. Controlling this type of technology has long been in the experimental stage and could become viable in the future. Well, maybe the future has come sooner than expected.

A fusion reactor is a device which uses nuclear fusion to generate energetic plasma used for the French President Chirac delivers a speech as he toured the future site of the ITER fusion project in Cadarache, France.generation of electricity. Engineers at the University of Tennessee, Knoxville (UT) have successfully developed an experimental reactor that can demonstrate the feasibility of fusion energy for the power grid. This development was built on the idea of nuclear fusion supplying more energy with far fewer risks. This milestone is integral for the ITER project which was founded on the idea of building a fusion reactor that aims to produce ten times the amount of energy that it uses. ITER involves the United States, the European Union and five other nations and its goal is to help bring fusion power to the commercial market. UT researchers accomplished a crucial step for the project by favorably testing their technology that will insulate and stabilize the central solenoid -- the reactor’s backbone.

UT engineering professors and students hope to establish technology that serves to insulate and provide structural integrity to the central solenoid. A tokamak reactor uses magnetic fields to confine the plasma, which is the electrically charged gas that serves as the reactor fuel. The central solenoid consists of six giant coils stacked on top of one another and it ignites and steers the plasma current. The answer to solving the technology was finding the right material and the right process of inserting that material into all of the required spaces of the central solenoid. The material is a glass fiber and epoxy chemical mixture that is liquid at high temperatures and hard when cured. The mixture provides electrical insulation and strength to the heavy structure. The impregnation process moves the material at a certain pace, factoring in temperature, pressure, vacuum and the material’s flow rate. Another determining factor is time --  with the epoxy there are numerous competing parameters. The higher the temperature, the lower the viscosity; however at the same time, the higher the temperature, the shorter the working life of the epoxy. This week, the UT team tested the technology inside its mockup of the central solenoid conductor. Results were positive.

Two years of technology development and two days of the impregnation process were a step in the right direction. This energy can be channeled to do primarily the same job that fossil fuels do: It can heat water to make steam, and the steam is then used to turn the blades of a turbine in a generator. The turning of the turbine runs the generator, producing electricity.

The power generation produces lower carbon dioxide and other greenhouse gas releases. Obviously, this has been a significant problem with fossil fuel use. Therefore, there needs to be alternative energy means other than fossil fuels. The critical issue at stake is trying to reconcile the constant expanding demand of the world’s population to raise their standard of living with the environmental hazards resulting from current energy supply. Large power generating-capacity is able to meet industrial and city needs. Low-power technologies such as solar, although sustainable, meet mostly local or residential needs. Heavy manufacturing would still be a challenge for growing industries.

Nuclear energy has been surrounded with controversy from the very beginning, centering mostly on safety issues. However, UT biomedical engineering professor Madhu Madhukar has confirmed that fusion power is safer and more efficient than nuclear fission power, which was the basis for past nuclear disasters. He states, “There is no danger of runaway reactions like what happened in nuclear fission reactions in Japan and Chernobyl, and there is little radioactive waste.” This recent development in fusion reaction can lead to large changes in terms of energy consumption and the depletion of valuable resources. The benefits begin with the unparalleled energy density of the fuel used for nuclear energy. Just one uranium fuel pellet -- roughly the size of the tip of an adult’s little finger -- contains the same amount of energy as 17,000 cubic feet of natural gas, 1,780 pounds of coal or 149 gallons of oil. More advantages include life-cycle emissions of carbon dioxide, nitrogen oxides and sulfur dioxide that are lower than all fossil fuel forms as well as solar photovoltaic and forestry waste biomass. Additionally, the electrical energy from nuclear power plants is available when needed, not just when the sun is shining or when the wind is blowing. Nuclear power plants could provide a stable base of energy. The electricity production from the plants can be lowered when good wind and solar resources are available and cranked up when the demand is high.

Fossil fuels were the energy source that shaped the 19th and 20th century. However, burning coal, oil and gas has proved highly damaging to the global environment. Carbon dioxide emissions, greenhouse effect gases and fumes all contribute to the disruption of the planet’s climate. The UT research has implemented a positive domino effect for fusion reactors and nuclear energy. A more sustainable planet is what nations have worked tirelessly for and nuclear energy can be a key solution. This type of energy has great prospects in the near future due to its efficiency, and it does not produce any kind of pollution. If nuclear energy is exploited well, resource scarcity could no longer be a problem.