Nuclear Waste Definition, Types, Sources, Problems, Explained
Nuclear waste is unwanted material that contains radiant energy due to long-term radioactive exposure, or potent radionuclide content. This article discusses nuclear waste definition, types, sources, and problems, as outlined below;
-Nuclear Waste Definition: 5 Ways to Define Nuclear Waste
-Why Nuclear Waste is a Problem
Nuclear Waste Definition: 5 Ways to Define Nuclear Waste
Nuclear waste refers to any useless and/or discarded material that is capable of emitting harmful radiation into its surroundings.
The above is a simplistic and basic definition of nuclear waste, which highlights its most definitive attributes. Below is an alternative nuclear waste definition that sheds light on its sources;
Nuclear waste is hazardous waste material that is derived as a byproduct of radioactive elements and processes such as the utilization of uranium isotopes as fuel to produce nuclear energy for electricity generation, and the development or deployment of nuclear weapons [1].
Next, the nuclear waste definition is given in terms of the basic composition of these waste materials;
Nuclear waste is any hazardous useless material that contains traces of radioisotopic elements like plutonium, thorium, radium and uranium, alongside others like germanium, iodine, zinc, silver and iron [3].
The effects of nuclear waste are crucial toward understanding its attributes, and especially the threat which it poses to the natural ecosystem.
Another definition of nuclear waste is given below, which highlights some of these effects;
Nuclear waste refers to useless and/or discarded radioactive material, which can be hazardous to the ecosystem, with effects such as; environmental pollution, genetic mutation in animals and plants, and health problems like cancer, cataracts and cardiovascular disease in humans [8].
Lastly, the definition of nuclear waste is given within the context of its management, as follows;
Nuclear waste is a form of hazardous waste that is capable of emitting harmful radiation into the environment, and which can be managed using various measures like recycling, immobilization, storage and disposal.
Types of Nuclear Waste
Types of nuclear waste are; low-level waste (LLW), intermediate-level waste (ILW), high-level waste (HLW), mill railings, and transuranic waste.
Of these, the three main types of nuclear waste are; high-level, intermediate-level, and low-level wastes. These three are classified based on their level of radioactivity, which is proportional to the severity of their effect on the environment.
Mill tailings and transuranic nuclear wastes are classified based on their compositional characteristics.
Below is a brief explanation of each nuclear waste type respectively;
1). Low-level Waste (as one of the Types of Nuclear Waste)
Low-level waste refers to non-radioactive material that has acquired radioactive properties through exposure to nuclear radiation, and/or contamination by radioactive materials.
Examples of low-level waste are; cleaning materials, medical equipment, nuclear treatment effluent, components of nuclear reactors, laboratory implements, and protective gear from nuclear power plants.
These materials become 'nuclear waste' through exposure to radioactive conditions, for significant periods of time.
Very low-level waste is a subtype of low-level waste, which is harmful to the environment, but does not require intensive measures for its disposal [9].
Often, shallow landfill-burial is suitable for effective disposal of very low-level wastes, and the duration of their hazardous effect is shorter than that for other types of nuclear waste.
Specific materials or items that can be described as low-level nuclear waste include; wood, cleaning rags, ion exchange resins, filters, shoes, clothing, syringes, and organic biomass.
2). Intermediate-level Waste
Intermediate-level waste (ILM) is produced from active involvement in, and close proximity to, nuclear reactions.
Types of intermediate-level waste include nuclear reactor core components, and none-core components.
Examples of intermediate-level waste are; radioactive fuel cladding (reactor core component), and ion-exchange resins (none-core component).
In a comparison of LLW vs ILW, the intermediate-level waste scores higher in its radioactive content and potency. However, both types of nuclear waste are derived from power plants, laboratories and other points of possible exposure to (and interaction with) radioactive materials [5] [7].
Intermediate-level waste is disposed by long-term burial in geologic formations. The duration for total detoxification of such waste materials ranges from several hundred to hundreds of thousand years, depending on specific size, composition and concentration.
3). High-level Waste (as one of the Types of Nuclear Waste)
High-level waste is made of spent nuclear fuel (SNL), and it is created by the utilization and reprocessing of nuclear fuel in a reactor [2].
An example of high-level waste is control rods from the core of nuclear reactors.
It is called 'high-level' waste because this type of nuclear waste is capable of emitting significant amount of radiant energy, and can be very harmful to both biotic and abiotic components in its surroundings.
High-level waste is the most hazardous type of nuclear waste, requires intensive measures for its effective disposal, such as isolation under non-reactive conditions, at significant subsurface depth.
4). Mill Tailings
Mill tailings, or uranium mill tailings (UMT) are produced from the processing of uranium ore to produce nuclear fuel.
These materials occurs as small-grained residue from uranium ore milling (grinding) and chemical concentration. They usually constitute a sandy mass that contains mainly uranium and heavy metals, among other elements.
Other forms of mill tailings can comprise of radioactive decay products, or other primary radioisotopes.
Radium mill tailings is the sandy radioactive waste derived from the processing of radium.
It must be noted that mill tailings are different from high-level waste or spent fuel, which is gotten from nuclear reactor cores after radiant energy has been extracted from radioisotopes.
Mill tailings are usually disposed by impounding the waste in inert environments, on the surface [6].
5). Transuranic Waste (as one of the Types of Nuclear Waste)
Transuranic means beyond Uranium.
For transuranic waste, this type of nuclear waste comprises dominantly of elements that are heavier than uranium, having a higher mass number.
Nuclear waste becomes transuranic when it contains significant amount of these alpha-emitting elements [4]. In most cases, the transuranic elements are manmade.
Transuranic waste has a high level of toxicity and requires long-term isolation from the environment for its disposal.
Sources of Nuclear Waste
Sources of nuclear waste are;
1). Nuclear reactors
2). Hospitals
3). Nuclear fuel processing facilities
4). Nuclear research facilities
5). Nuclear weapons like the atomic bomb
Activities that can lead to the production and/or release of nuclear waste include;
1). Mining
2). Fuel processing
3). Nuclear plant decommissioning
4). Weapon development or detonation
5). Nuclear medical implementation
Why Nuclear Waste is a Problem
Nuclear waste is a problem because it emits harmful radiant energy, that can be very destructive and hazardous to all components of its surrounding. This implies that it is a very dangerous form of industrial waste.
Nuclear waste is dangerous as a result of its capability to release such harmful radiation, and the risk which it poses to the ecosystem.
The problems or dangers of nuclear waste are;
1). Harmful radiant energy emission
2). Long-term potency
3). Polluting effect on soil, water and air
4). High risk during transport
5). Damaging effect on plant and animal matter
Also, the problems of nuclear waste are made more serious by the difficulty of their effective disposal; where methods like burial and vitrification can be very challenging (technically and financially) and are still prone to devastating errors.
Conclusion
Nuclear waste is any useless material that is capable of emitting harmful radiation as a result of exposure to, or contamination by radioisotopes.
Types of nuclear waste are;
1. Low-level Waste
2. Intermediate-level Waste
3. High-level Waste
4. Mill Tailings
5. Transuranic Waste
Sources of nuclear waste are; nuclear reactors, hospitals, nuclear fuel processing facilities, nuclear research facilities, nuclear weapons like the atomic bomb, and activities like mining, fuel processing, nuclear plant decommissioning, weapon development/detonation, and nuclear medical implementation.
Nuclear waste is a problem because it poses a major threat to soil, water, and air quality, as well as plant and animal health.
The problems or dangers of nuclear waste are; harmful radiant energy emission, long-term potency, polluting effect on soil, water and air, high risk during transport, and damaging effect on plant and animal matter.
References
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3). INTERNATIONAL ATOMIC ENERGY AGENCY (2003). "Combined Methods for Liquid Radioactive Waste Treatment." IAEA-TECDOC-1336, IAEA, Vienna (2003). Available at: https://www.iaea.org/publications/6583/combined-methods-for-liquid-radioactive-waste-treatment. (Accessed 4 February 2023)..
4). Joyce, M. (2018). "Nuclear Engineering. A Conceptual Introduction to Nuclear Power." Available at: https://www.sciencedirect.com/book/9780081009628/nuclear-engineering. (Accessed 4 February 2023).
5). Kónya, J.; Nagy, N. (2012). "Nuclear and Radiochemistry." Available at: https://doi.org/10.1016/C2011-0-06943-0. (Accessed 4 February 2023).
6). Landa, E. R. (2004). "Uranium mill tailings: nuclear waste and natural laboratory for geochemical and radioecological investigations." J Environ Radioact. 2004;77(1):1-27. Available at: https://doi.org/10.1016/j.jenvrad.2004.01.030. (Accessed 4 February 2023).
7). Yim, M. S. (2022). "Management of Low and Intermediate Level Waste." In: Nuclear Waste Management. Lecture Notes in Energy, vol 83. Springer, Dordrecht. Available at: https://doi.org/10.1007/978-94-024-2106-4_13. (Accessed.4 February 2023).
8). Zlobina, A.; Farkhutdinov, I.; Carvalho, F. P.; Wang, N.; Korotchenko, T.; Baranovskaya, N.; Farkhutdinov, A. (2022). "Impact of Environmental Radiation on the Incidence of Cancer and Birth Defects in Regions with High Natural Radioactivity." Int J Environ Res Public Health. 2022 Jul 15;19(14):8643. Available at: https://doi.org/10.3390/ijerph19148643. (Accessed 4 February 2023).
9). Zohuri, B. (2020). "Nuclear fuel cycle and decommissioning." Nuclear Reactor Technology Development and Utilization (pp.61-120). Available at: https://doi.org/10.1016/B978-0-12-818483-7.00002-0. (Accessed 4 February 2023).
