What is the problem with controlled fusion?

Controlled fusion, the process of harnessing energy from nuclear fusion reactions, faces several significant challenges:

Key Challenges

1. Fuel Supply and Tritium Production:

   • Tritium Availability: Fusion reactions typically require deuterium and tritium as fuels. Tritium is not naturally abundant and must be produced artificially, often using fission reactors, which introduces additional safety and proliferation concerns1.
   • Tritium Recovery: In magnetic confinement reactors, only a small fraction of injected tritium is burned before it escapes, necessitating complex recovery processes1.

2. Plasma Instability and Control:

   • Plasma Stability: Maintaining stable plasma conditions is crucial but difficult due to various instabilities, such as tearing modes, which can disrupt the reaction2.
   • Use of AI: Recent advancements involve using AI to predict and mitigate these instabilities in real-time, improving plasma control2.

3. Energy Efficiency and Parasitic Power Drain:

   • Parasitic Power Consumption: Fusion reactors consume a significant portion of their generated power for maintaining plasma stability and other operational needs, reducing net energy output1.
   • Economic Viability: To be economically viable, fusion reactors must operate at very high power levels to minimize the impact of parasitic power drains1.

4. Radiation Damage and Waste:

   • Neutron Radiation: Fusion reactions produce high-energy neutrons that cause radiation damage to reactor components, leading to structural degradation and the need for frequent replacements1.
   • Radioactive Waste: Although the radioactivity per unit mass is lower than in fission reactors, the total volume of waste can be much larger1.

5. Coolant and Water Demands:

   • Cooling Requirements: Fusion reactors require substantial cooling systems, which demand large amounts of water, potentially straining local resources1.

6. Capital Costs and Economic Challenges:

   • High Capital Costs: The construction and operation of fusion reactors are extremely costly, making them less competitive with other energy sources unless heavily subsidized1.

These challenges highlight the complexity and difficulty of achieving controlled fusion as a viable energy source.