Why is nuclear fusion considered a safer alternative to nuclear fission?

Nuclear fusion is considered a safer alternative to nuclear fission primarily because it cannot launch chain reactions. In nuclear fission, heavy atomic nuclei are split into smaller parts, which can lead to a cascade of further splits, creating the potential for uncontrollable reactions and meltdowns if not managed properly. This characteristic makes fission reactions inherently riskier, as they rely on the maintenance of precise conditions to avert runaway reactions.

In contrast, fusion involves combining light atomic nuclei, such as hydrogen isotopes, to form heavier nuclei, like helium. This process requires extremely high temperatures and pressures to overcome the electrostatic repulsion between the positively charged nuclei. If the conditions for fusion are not maintained, the reaction simply stops, preventing any uncontrolled release of energy. This fundamental difference in reaction behavior is a significant factor in the safety aspect of fusion compared to fission.

Furthermore, while fusion does produce energy, it generates far fewer radioactive byproducts than fission. This reduces the long-term waste disposal issues associated with nuclear power and lowers environmental risks. The requirement for fuel in fusion is also less, but this factor is secondary to the safety aspect related to chain reactions. Thus, the inability of fusion to sustain chain reactions is a key reason why it is viewed as