By Nitika Varadh
Introduction to Nuclear Waste Disposal:
Nuclear waste is essentially the toxic and radioactive byproduct generated from nuclear reactors, fuel processing plants, and nuclear medicine, resulting in small amounts of waste, known as fission products. It is a reflection of the vast use of technology and our inability to effectively manage humanity’s own advances. The disposal of such toxic waste is what we call Nuclear Waste Disposal. Nuclear waste is created everyday by humans, beginning 1896, when scientist Henri Becquerel discovered radioactivity. For the first few decades since its discovery, no law was enacted to manage nuclear waste disposal. However, on January 7, 1983, the Nuclear Waste Policy Act finally came into effect, permitting the use of deep geologic repositories for the safe storage and disposal of nuclear waste. The materials scientist of State University of Ohio, Gerald S. Frankel claims that, “regardless of whether [one supports the use of] nuclear power [or not], the radioactive waste is already here, and we have to deal with it, implying that immediate action must be taken towards safely disposing nuclear waste to protect our environment (Frankel 2020).
Types of Nuclear Waste:
Nuclear waste can be distinguished into three categories based on their levels of radioactivity: low-level waste, intermediate-level waste, and high-level waste. The majority of nuclear waste produced daily is composed of low-level waste items that make up 90% percent of the total radioactive waste. In contrast, high-level waste accounts for a mere 3 percent of the total waste we encounter.
Technology Used and Safety Issues:
The most common disposal methods are through storage via steel cylinders, vitrification, or deep and stable geologic formations. “Dry cask storage uses steel cylinders along with inert gas or water to seal the radioactive waste” (Xie 2013). These casks are typically steel cylinders that are either welded or bolted closed. Dry cask storage has proven to have released no radiation that affected the public or contaminated the environment, they are also a wonderful method to store away this waste safely, although they do have some minimalistic drawbacks such as leaks which could jeopardize public health and safety. On the other hand, the process of vitrification simply blends waste materials with a glass precursor and locks the harmful constituents in the glass matrix. And lastly, the use of geographic repositories requires the selection of appropriate geologic locations using conventional mining technology to dispose of harmful waste in landfills and areas far away from the general public. Additionally, although numerous safety precautions are taken prior to disposal, mistakes are prone to happen. If nuclear waste is disposed or stored improperly, even the most minute leakage could be severely damaging to the environment by ruining all air, water and soil quality, because of the longevity of nuclear waste. The nuclear decay of the waste produces many small particles of protons, neutrons, and electrons, that are capable of tearing through the tissue and damaging genetic material, leading to serious health concerns such as cancer.
Vitrification in depth and my standpoint:
Vitrification allows nuclear waste to stabilize and be encapsulated. First, “the waste is mixed with another substance that will crystallize when heated and then calcined. Calcination removes water from the waste which is later transferred into a heated furnace and mixed with fragmented glass. Upon mixing, the nuclear waste is bonded to the glass material and the melted product is poured into the vitrification plants/encapsulation container, which is ultimately sealed and stored away in an inaccessible area” (Diaz 2012). Vitrification causes immobilization in waste containing radioisotopes such as Tc-99, Se-79, and I-129, for the next thousands of years. However, despite vitrification being one of the safest methods of nuclear waste disposal, it does have its drawbacks:
High investment cost
High operational cost