Power to the People - the effectiveness and advantages of nuclear fusion

physicsmeme
physicsmeme
August 02

Introduction

Nuclear fusion is the process in which light atomic nuclei are being joined to create heavier nuclei. This process can happen up to iron-56, after which, the elements become too heavy to fuse together. Due to the loss of mass in the atoms produced, a huge amount of energy is released. Fusion was first theorized in 1928, and ever since it was proven to exist in 1950, the attempts to replicate it on Earth have been happening ever since, but unfortunately, all were unsuccessful. (Understanding the Process) To create nuclear fusion, high energy levels need to be met, so that the elements can combine to create new ones. On Earth, currently, there is no stable way to keep the energy levels very high (up to 108K) constantly, without melting the equipment and the reactor itself. (Freudenrich) Scientists want to control fusion in the next 30 years, as fusion is the cleanest energy in the universe. Unlike fission reactors, it has been theorized that fusion reactors (mainly based on Deuterium) will not produce any kind of nuclear waste, which uranium produces. Due to the effects of climate change, the Earth is getting hotter each century by 1K. (World of Change: Global Temperatures) If fusion can be successfully created and maintained on Earth, the use of any other fuels which produce CO2, will become redundant and Earth could recover from the damage done by humans in the last two centuries. (Fusion: Energy of the Future)

Applying physics

The simplest and most predominant type of fusion is from hydrogen to helium. Stars use this fusion as their fuel, which keeps them ashine. This type of fusion is represented like this:

Figure 1: Fusion of hydrogen into helium at Sun's core<br>
Figure 1: Fusion of hydrogen into helium at Sun's core

Even though this is the most efficient type of fusion, more resources and energy are needed, so that it could be replicated on Earth. The type of fusion which is currently being studied, is the deuterium-tritium fusion, because the least amount of energy is needed for the atoms to fuse together and the resources for it are widely available (D from the sea and T from Li-7) (Fueling the Fusion Reaction)

Figure 2: Deuterium-tritium fusion<br>
Figure 2: Deuterium-tritium fusion

The energy released from fusion is measured in electron volts (eV), which is the kinetic energy a single electron receives, traveling through 1V of energy in vacuum. So, 1eV = 1V × elementary charge or 1eV = 1V × (1.602176565 × 10-19C). (Wallenfeldt) The energy released from this type of fusion is 17.6 MeV, while from the proton-proton fusion releases 26.7 MeV. (Augustyn) Even though, using D-T fusion, produces less energy than proton-proton fusion, it still releases 4 × 106 times more energy than conventional fuel sources, such as oil and coal. (Advantages of Fusion)

The biggest strengths of nuclear fusion, and the reasons why scientists are trying to produce it, is due to it being a clean for the environment, highly efficient, energy source. Research is being done all across the globe to achieve nuclear fusion as fast as possible, so that it can be mass produced and used, before the climate change effects on Earth reach a point when they are no longer reversible. European Union, Japan, USA and other highly economically developed areas, invest huge amounts of money into fusion research. The UK believes that fusion can be achieved by 2040 and “Net Zero emissions” by 2050. This means that the UK plans to create zero energy waste and zero pollution out of the energy sources used. (McGrath) The energy needed to create nuclear fusion is highly abundant, not just on Earth, but in the whole universe. Comparing this to crude oil, or coal, which can only be found on Earth and its resources are limited.

Evaluation

The use of fusion reactors and its implication to the world will interact with the environmental factor to a great extent. Unlike fission nuclear reactors, which are currently in use all around the globe, a fusion reactor, called a tokamak (toroidal chamber with magnetic coils), will create zero nuclear waste. (Tokamak) Nuclear reactors create around 2 × 10^6g of nuclear waste (such as 228Ra and 99Tc) a year, in the United States alone. (Biello) The only side product of nuclear fusion that will be used on Earth, as an energy source, is a neutron, which cannot harm the environment in any way, shape or form. The conditions met in a tokamak, do not allow the disasters and nuclear fall-outs to happen, such as in Chernobyl or Fukushima. The plasma created in a tokamak can be cooled down in mere seconds. Since there is no energy stored in the tokamak, a chain reaction cannot ensue, since all the energy has been sent out of the machine and into the energy supply system. (Advantages of Fusion)

The use of nonrenewable energy sources has started rapidly rising since the Industrial Revolution and the yearly CO2 emissions have been rising coinciding with that. As can be seen on Figure 3, there is currently no slowing down of the CO2 emitted into the Earth’s atmosphere, but fusion will change that. Carbon dioxide is a greenhouse gas which is by far, mostly released into Earth’s atmosphere.

Figure 3: Yearly CO2 emissions from 1970 to 2012<br>
Figure 3: Yearly CO2 emissions from 1970 to 2012

There is one great economical disadvantage of using nuclear fusion, rather than conventional energy resources. The cost of building a sustainable fusion power plant is very high, and “ITER [International Thermonuclear Experimental Reactor] estimates the cost of design and construction at about 20 billion euros...” (Fountain) This number is an estimate for only one fusion reactor. Comparing this to the average cost of a medium-sized fission reactor, which is 660 million euros, the cost for a fusion reactor is 30 times more expensive to build and the fusion reactor might not even work as intended. (Fehrenbacher) Another problem that the fusion reactor has is that the predicted amount of energy produced by the fusion reactor is around the same as the fission reactor (around 1 GW). (Advantages of Fusion)

Conclusion

Nuclear fusion and its use have only advantages towards the environment and once nuclear fusion is achieved, the use of energy sources which harm the environment; the ones which produce CO2 and other deadly toxins, will rapidly go to zero. The stoppage of the use of the nonrenewable energy sources will drastically lower the changing of the climate and the rises in temperature. Humans depend on energy and if the use of nonrenewable sources continues, they will eventually run out. The switch to the renewable and clean sources has already started, with the use of wind power, solar power, geothermal energy, and more, but when the use of fusion becomes worldwide, the cost of energy will go down, since the materials used to create fusion are all-abundant, and the energy produced by a tokamak will be much greater than the energy being currently produced by conventional energy production plants.

Bibliography

“Advantages of Fusion.” ITER, 2020, www.iter.org/sci/Fusion

“Fueling the Fusion Reaction.” ITER, 2020, www.iter.org/sci/FusionFuels.

“Fusion: Energy of the Future.” Iaea.Org, 31 July 2001,  link

“Tokamak.” ITER, 2015, www.iter.org/mach/Tokamak.

“Understanding the Process.” NobelPrize.Org, 2020, .

“World of Change: Global Temperatures.” Nasa.Gov, NASA Earth Observatory, 29 Jan. 2020, earthobservatory.nasa.gov/world-of-change/global-temperatures.

Augustyn, Adam. “Proton-Proton Cycle | Astronomy | Britannica.” Encyclopædia Britannica, 2020, see here.

Biello, David. “Spent Nuclear Fuel: A Trash Heap Deadly for 250,000 Years or a Renewable Energy Source?” Scientific American, 28 Jan. 2009, more .

Conn, Robert W. “Nuclear Fusion - Fusion Reactions in Stars | Britannica.” Encyclopædia Britannica, 2020, more here.

Fehrenbacher, Katie. “Nuclear Power By the Numbers.” Gigaom.Com, Gigaom, 19 Feb. 2010, gigaom.com/2010/02/19/nuclear-power-by-the-numbers/.

Fountain, Henry. “A Dream of Clean Energy at a Very High Price.” The New York Times, 27 Mar. 2017, more here.

Freudenrich, Craig Ph. D. “How Nuclear Fusion Reactors Work.” HowStuffWorks, 11 Aug. 2005, science.howstuffworks.com/fusion-reactor2.htm

McGrath, Matt. “Nuclear Fusion Is ‘a Question of When, Not If.’” BBC News, 6 Nov. 2019, www.bbc.com/news/science-environment-50267017.

Wallenfeldt, Jeff. “Electron Volt | Unit of Measurement | Britannica.” Encyclopædia Britannica, 2020, more here.

Images used

Figure 1: Self-made,adapted from “Nuclear Fusion in the Sun - Energy Education.” Energyeducation.Ca, 2015, - img.

Figure 2: Self-made, adapted from “File:Deuterium-Tritium Fusion.Svg - Wikimedia Commons.” Wikimedia.Org, 7 May 2007, - img link .

Figure 3: Edited and adapted from “CO2 Emissions (Kt) | Data.” Worldbank.Org, 2017,  - link .

Power to the People - the effectiveness and advantages of nuclear fusion

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