Talking about nuclear energy sparks controversy. From nuclear power plant disasters to the radioactive fallout after those events, nuclear power’s reputation is polarized. It is the second cleanest energy source (after hydropower) as it has zero emissions and high performance; but at the same time, it produces radioactive waste and when power plants malfunction, bad things happen.
Nuclear power is the use of nuclear reactions to generate energy. There are three technologies that can be used to achieve it: nuclear fission, nuclear decay and nuclear fusion. Most nuclear reactors in operation today use fission. Fission is the splitting of atoms to release energy. Uranium is the most popular fuel for fission reactions; however, there are alternative fuels like plutonium and thorium.
Even though fission power plants today follow the highest safety standards to avoid accidents like the ones in the past; people are still skeptical regarding nuclear. Disasters like the one in Three Mile Island, Chernobyl, or more recently Fukushima have really left a mark on society and are the cause of nuclear power’s bad reputation among lots of people. After the Fukushima event, countries like Switzerland and Spain have stopped or banned construction of new reactors; and Germany is in a process of nuclear power phase-out. For other countries however, nuclear power still constitutes a big portion of their electricity generation. In the U.S., nuclear power plants generate about 20% of the country’s electricity. The U.S. also generates more nuclear power than any other country, followed by France, Russia, China and South Korea.
Nuclear fusion in contrast to fission, is the merging of small atoms into larger ones to release energy. Hydrogen nuclei collide and fuse turning into helium atoms, releasing tremendous amounts of energy in the process. It is the energy source of stars and the sun. Almost all the research under development is directed at producing power from the deuterium-tritium (DT) reaction as it has been found to be the most efficient one, producing the highest energy gain at the “lowest” temperatures. Do not be fooled, extremely high temperatures are still needed to achieve fusion conditions (around 150,000,000° Celsius, way higher than the temperature of the sun). There are two more requisites for fusion: sufficient plasma particle density and sufficient confinement time to hold plasma within a defined volume.
One of the pros of fusion is that it releases more energy than fission. In addition, fission carries the risk of a meltdown and creates radioactive waste; but fusion promises to be a meltdown-proof and waste-free abundant energy source. That promise makes it one of very few sustainable options in the quest of replacing fossil fuels as the world’s primary source for energy generation.
No one has created a fusion reactor that generates more energy than it uses, yet. One project underway is ITER, a collaboration between the European Union, China, India, Japan, Korea, Russia, and the United States that plans to be powered on at the end of 2025. Another one is Norman by TAE Technologies, a 100-foot-long prototype nuclear fusion reactor. Fusion is not ready for the market. We are going to have to keep dreaming of this energy source for decades before a commercial fusion reactor exists; but scientist keep building prototypes and working to overcome their limitations. If a stable nuclear fusion reactor is developed, it would completely revolutionize the future of energy as it uses hydrogen and there are no harmful products.
Will fusion have the same bad reputation as current fission nuclear reactors? I do not know; but the technology looks promising and if innovation overcomes all the current hurdles, it may be the answer we have been waiting for. Generating clean and abundant energy is THE dream; and even though renewables are important in achieving sustainability goals, those will be very difficult to achieve without nuclear. We just have to be patient and wait for these prototypes to work efficiently and at an appropriate scale.
S. Cowley. The quest for fusion power (2016), U.S. Energy Information Administration, Forbes, Iter.org
Featured image: Yale Climate Connections