Everyone says that fusion is a clean energy. Tokamak is the most successful and promising fusion confinement device developed by scientists. The doughnut-shaped vacuum vessel is designed to hold a plasma suspended by powerful magnetic fields. If the very hot plasma were to touch the walls of the vacuum vessel, it would lose its heat or become contaminated with metal atoms, or both. A large current, up to several million amperes, flows through the plasma.
Fusion power is attractive from the environmental viewpoint.
Clearly, the first fusion power reactors will not be free from radiation. The strong neutron flux in the reactor core will contaminate the reactor walls and blanket, and long-time storage will be required for this material.