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| Fig. 1: Watts Bar PWR in use. (Source: Wikimedia Commons). |
Nuclear power, also known as nuclear energy, is a method that many different countries use to create electricity worldwide. The potential for nuclear power was first realised after Earnest Rutherford, a New Zealander, split the atom which released a large amount of heat energy. [1] The very first nuclear power plants were developed in the 1950s and 60s. [2] Nuclear power plants have the potential to produce energy relatively cleanly, but they can also be dangerous. Yet even with the potential danger, 14% of the world's power was still generated from nuclear energy in 2011. [3] But how does nuclear energy exactly work and why can it be so dangerous?
Now that we know that nuclear power is energy produced from splitting an atom, let us look at how it is actually implemented. The most common type of nuclear reactor that is used to produce nuclear power is a pressurised water reactor, also known as a PWR. [4] A PWR in use can be seen in Fig 1. In a PWR when the uranium atom is split, known as nuclear fission, heat is produced. This heat is then absorbed by the water which immediately surrounds the uranium which heats the water to "temperatures over 300°C," but "this water is kept liquid under high pressure." [5] The heat from this water is then used to heat and boil a second water circuit which turns into steam which turns the turbine. [5] Finally the steam in the second water circuit is cooled and recycled in the second circuit. [5] As a result of this process electricity is produced, through the turning of the turbine, which can be used to power cities and countries.
If a PWR is run properly, there is little danger due to inbuilt safety features. However, events such as earth quakes and tsunamis can cause damage to nuclear reactors that can override and destroy safety features. This is what occurred in the 2011 Fukushima Nuclear Disaster, caused by an earthquake and subsequent tsunami. The earthquake and tsunami caused numerous districts of Fukushima to lose power which ultimately lead to the "failure of the cooling system in TEPCO's Fukushima Daiichi nuclear power plant", which resulted in a "series of nuclear meltdowns and hydrogen-air chemical reactions that caused a release of highly radioactive material into the environment surrounding the plant." [6] Since the 2011 Fukushima Nuclear Disaster "approximately 9 × 1015 Bq of radioactive substances have been released" which has affected nearly "1800 square kilometres of land in Japan." [7] Such a large amount of radiation has the potential to seriously harm a lot of people. When humans are exposed to radioactive materials that emit radiation, "there is a risk that it causes chemical changes in cells which can kill or makes cells abnormal," which is why is what makes nuclear power so dangerous. [8]
Although nuclear power doesn't produce any green house gases like alternative energy production methods, such as burning fossil fuels, it does have the potential to be dangerous in its own way. Therefore as we move forward in looking for methods to produce renewable and clean energy that don't damage the climate, we must be sure to look at the risk-benefit ratio.
© Emma Alderton. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
[1] G. Nagendrappa, "Ernest Rutherford The Man Who found Nucleus in the Atom," Resonance 16, 1007 (2011).
[2] "An introduction to Nuclear Power Science, Technology and UK Policy Context," Sustainable Development Commission, March 2006.
[3] "A Nuclear-Powered World," National Public Radio, 16 May 11.
[4] G. Tuayev-Deane, "A Brief Overview of Common Nuclear Reactor Technologies," Physics 241, Stanford University, Spring 2018.
[5] K. Agyeman, "Differences Between BWRs and PWRs," Physics 241, Stanford University, Winter 2018.
[6] D. Sarkisian, "Effect of Fukushima Nuclear Disaster on Japanese Ecosystems ," Physics 241, Stanford University, Spring 2017.
[7] A. Barr, "Fukushima: A Comparison to Other Nuclear Accidents," Physics 241, Stanford University, Spring 2015.
[8] H. Shimp, "Effects to the Human Body From Nuclear Fallout," Physics 241, Stanford University, Winter 2017.
