What are the main challenges and risks of nuclear waste management and disposal?

Mixed Waste (Low and High-level Waste combined) also exists and has segregation and code of federal regulation requirements associated with disposal. For example, the Mixed Waste cannot be buried with the Low-Level Waste for disposal.

The classification of nuclear waste is crucial in determining its management and disposal. It's worth noting that while low-level waste comprises the majority of the volume, its radioactivity is minimal. Conversely, high-level waste, though small in volume, carries the most significant risk due to its high radioactivity and longevity. This highlights the importance of focusing on efficient and safe disposal methods for high-level waste, despite its smaller volume.

Wait, what waste? Only France & Russia have tiny amounts of waste, everyone else has 96-99% Stored Nuclear Fuel. So, mostly still fresh fuel, that must Not be thrown away because it contains30-170x as much energy as the first use. We musn't waste perfectly good fuel. It violates IAEA Guidelines on Sustainability!

No human institution has lasted long enough to ensure safety of fission products stored on earth. Use thorium SMR, recycle waste to lower levels. High level waste in fuel rods containing Transuranium Actinides have half lifes exceeding the time since the first human civilization.

In my experience as nuclear engineer, High Level Radioactive Waste (HLRW) is the main challenge of rad. waste management. One of the proposed approaches is by underground repository in a stable rock formation for over 1000 years. The multiple containment system (canisters & basalt rock) facilitates the decay of long-lived radionuclides & their heat. One thing I've found important is the choice of an ocean island to build repository facility. Sea water dilution contributes to safety measures prior to waste exposures to human. I've estimated from a study at Genting Island (Ivan Affandi et. all, 1997) of the 11 nuclides w/ various retardation factors, C-14, Tc-99 & I-129 showed the dominant release rate of 100, 61.6 & 7.67 Ci/a consecutively.

The process of nuclear waste management is complex and requires meticulous planning. The categorisation and conditioning of waste are critical steps to ensure safety. However, the choice of containers and their materials is equally important, as they must withstand various stresses for an extended period. Moreover, the interim storage period can pose challenges due to the long half-life of some radioactive materials. It's crucial to continually develop and improve technologies for waste treatment and storage to minimise risks.

The management of nuclear waste indeed presents a multifaceted challenge. It's important to highlight that the development of advanced nuclear technologies can potentially reduce the volume and toxicity of nuclear waste. Also, international cooperation can play a significant role in sharing best practices, research, and technology to address these challenges. Lastly, public acceptance is often overlooked but is crucial in the decision-making process for nuclear waste disposal.

There needs to be content added on how to design nuclear technologies and activities up front in direct consideration of prevention and mitigation of wastes from the outset. This is an incremental cost that pays dividends in the future. For example, use materials that result in reduced activation, collect contaminants in places where they can be concentrated and packaged, think about how to keep systems (and the plant) clean, design facilities to accommodate efficient decommissioning sequences, recovery of materials and even recycling. All of these can reduce dose to workers, reduce wastes to be managed and reduce environmental impacts.

Despite decades of effort, the nuclear industry does not yet have a working solution for managing spent fuel and high level waste, the most radioactive products generated by nuclear power plants. Although many scientific and technical bodies have endorsed geological disposal as the preferred solution to this problem, there remain significant uncertainties about the long-term performance of repositories and behavior of the nuclear wastes to be stored in these facilities. Apart from a minority of countries, most countries have not chosen any sites for a repository. Further concerns about the long-term safety of repositories arise from the experiences of failures and accidents at pilot facilities.