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| Fig. 1: Types of radiation exposure and their respective level measured in mSv (millisieverts). [7,8] (Image Source: J. Santos) |
Nuclear waste includes not only byproducts of nuclear energy production (from reactors, research facilities, etc.), but also any waste generated after the decommissioning of such facilities. It is usually divided into the categories of high-level and low-level waste. This report will focus primarily on high-level waste (HLW). It derives from spent Uranium fuel from a nuclear reactor. It no longer produces electricity but is extremely radioactive.
The danger of such waste is chiefly due to fission products such as Cs-137 and Sr-90. These two isotopes generate most of the heat and penetrating radiation of HLW. Pu-239 is also dangerous, not because it produces penetrating but because of its long decay time and chain of radioactive decay daughters. While Sr-90 and Cs-137 have half-lives of about 30 years, Pu-239 has a half-life of 24,000 years. [1]
To understand how HLW would affect a person, Fig. 1 shows different levels of radiation that occur in our daily lives, as well as the lethal dose if delivered in one hour. For HVW removed from a reactor, after ten years, the surface dose rate is higher than 100,000 mSv/hour. As shown in Fig. 1, this is well above the fatal dose for any human being.
While as many as sixteen European countries contribute to the continent's nuclear waste, either from power plant operation, spent fuel management, or decommissioning, the three countries that clearly stand out as being the main contributors (excluding Russia and Slovakia) by the end of 2016 were France, the United Kingdom, and Germany, in order of the most significant contributor. [2] By December 31, 2016, the World Nuclear Waste Report showed that out of the 60,500 tons of spent nuclear fuel stored across Europe, the three countries mentioned above account for close to 50 percent of the total. Fig. 2 shows how much nuclear energy was a part of these three countries' total energy produced. It also includes data from Spain, the fourth biggest contributor.
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| Fig. 2: Comparison of nuclear energy percentage of total energy production between Europe's top four biggest nuclear waste contributors. Image Source: J. Santos, after the IEA. [3-6] |
According to the 2021 Energy Policy Review, France, the biggest European nuclear energy and waste contributor, has a total of 56 nuclear reactors (all of which are PWR, pressurized water reactors). [3] These generated 354 TWh (Terawatt-hours) in 2020. France relies so heavily on nuclear energy that it accounted for 67% of total electricity generation in 2020. [3] While many countries in Europe are focused on decommissioning all their reactors in response to public pressure, France is currently finishing construction of a brand new PWR in Normandy. [3]
Despite being Europe's second highest nuclear energy producer, the United Kingdom only has 15 reactors operational (based on IEA's 2019 report) a significant difference from France's 56. [4] In 2017, its nuclear plants generated 70.3 TWh, which amounted to 10.4% of the UK's total primary energy supply (TEPS) and 21.0% of their total energy generation. [4] Like France, the UK also has two ongoing new nuclear reactors under construction. These aim to have a grid connection by 2030.
Germany, based on the values provisionally reported in 2018 in the 2020 Energy Policy Review, has seven active reactors. [5] These produced 76.0 TWh, or 11.8% of the country's total electricity generation. [5] Despite contributing to approximately 30% of the total power generation in 2011, after the Fukushima Daiichi accident the German government made the decision to phase out all nuclear power generation by 2022. Since then (up to 2018), Germany has shut down ten of its plants.
Nuclear waste storage is typically done in one of two ways: wet storage in reactor cooling pools or dry storage in casks. [2] These cooling pools store spent fuel rods and are typically made of thick reinforced concrete and are over 40 feet deep. Once the spent fuel rods have been cooled for at least five years (but normally around ten years), they can be moved into dry cask storage, made of stainless steel on the inside and concrete on the outside. [1]
The current issue with the HLW in Europe is that it is primarily stored in cooling pools (wet storage), which is considered more dangerous than dry storage. The World Nuclear Waste Report in 2019 recommended that in most cases it would be safer to transfer this spent nuclear fuel (SNF) into dry storage facilities. In 2019, 60,000 tons of SNF existed in Europe, with France holding 25 percent, Germany having 15 percent, and the United Kingdom having 15 percent. [2] As the decommissioning of nuclear facilities continues, the need for SNF storage will increase rapidly. The current storage facilities in Europe are reaching capacity.
© Joana Santos. 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] "Radioactive Waste," U.S. Nuclear Regulatory Commission, January 2024.
[2] "World Nuclear Waste Report 2019," Focus Europe, November 2019.
[3] "France 2021: Energy Policy Review," International Energy Agency, November 2021.
[4] "Energy Policies of IEA Countries: United Kingdom 2019 Review," International Energy Agency, June 2019.
[5] "Germany 2020: Energy Policy Review," International Energy Agency, February 2020.
[6] "Spain 2021: Energy Policy Review," International Energy Agency, May 2021.
[7] N. E. Bolus, "NCRP Report 160 and What It Means for Medical Imaging and Nuclear Medicine," J. Nucl. Med. Technol. 41, 255 (2013).
[8] Z. Jaworowski, "Radiation Risk and Ethics," Physics Today 52, No 9, 24 (1999).