Waste management infrastructure for nuclear power plants is crucial because reactors produce waste that can be extremely harmful if not handled properly.
Nuclear power plants are known for being efficient and clean sources of energy, but they also generate radioactive waste that can be deadly if mismanaged. Therefore, having proper disposal infrastructure in place is essential.
Nuclear power plants primarily produce lower and intermediate levels of radioactive waste during routine cleaning activities. However, they also produce high-level waste through the burning of uranium fuel.
High-level waste (HLW) can emit fatal radiation doses during short periods of direct exposure, necessitating specific disposal procedures to be in place.
Lower and intermediate levels of radioactive waste are less dangerous compared to HLW. While their disposal procedures may not be as extensive, they are still crucial for ensuring safety.
Disposal procedures for lower-level radioactive waste typically involve contaminated equipment from nuclear power plants such as clothing, mops, and tools. This waste does not require shielding during handling and transport and can be disposed of near the surface.
On the other hand, intermediate-level waste (ILW), which includes outer jackets of fuel rods, requires some shielding. Therefore, smaller and non-solid waste is solidified in concrete or bitumen before disposal.
Furthermore, near-surface repositories may not be sufficient for certain ILW, which may require a deeper deposit similar to high-level waste.
In terms of high-level waste management, multi-barrier geological deposits are internationally recognized as the most effective method. This involves immobilizing waste in insoluble material like borosilicate glass and sealing it in a corrosion-resistant material such as stainless steel.
The waste is then isolated from people and the environment in a stable underground structure. In wet repositories, containers are surrounded by impermeable backfill to prevent radiation migration.
Cooling is an essential step before burying high-level waste to prevent an increase in temperature. Spent fuel from nuclear reactors is stored in specialized ponds made from reinforced concrete and steel liners for cooling.
After a period of cooling, some fuel may be stored in dry casks or concrete shielding without air circulation. Structured groups of fuel rods may be held in sealed steel casks or multi-purpose canisters to transport and dispose of the spent fuel.
Reprocessing spent fuel is another method to manage high-level waste by recovering and converting spent uranium and plutonium into mixed oxide (MOX) for fueling reactors. This process can extract more energy from uranium ore and reduce the volume of HLW significantly.
The waste left after recycling is fission products, which decrease in radiation level over a shorter period compared to plutonium and uranium. Recycled HLW takes only 9,000 years to decay to the same radiation level as the original ore, affecting waste disposal management.
In real-world examples of nuclear waste management, France leads in nuclear energy with a significant portion of its electricity generated by nuclear power reactors. The French approach focuses on recycling spent fuel to increase efficiency and fuel security while minimizing HLW.
However, the construction cost of reprocessing plants can be substantial, as seen in Japan’s Rokkasho Reprocessing plant. The United States, on the other hand, does not reprocess its spent fuel, making waste management more complex due to varied reactor types.
In contrast, Australia banned nuclear power in 1998 but has the largest uranium reserves globally. Despite the ban, Australia has a nuclear reactor in Lucas Heights used for academic and medical purposes and is preparing its workforce for nuclear submarine operations under the AUKUS agreement.
Efforts to lift the ban on nuclear power in Australia have been unsuccessful, but there is a growing push against the ban, notably by Opposition leader Peter Dutton, who advocates for establishing nuclear power in the country.
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