Question

Why is fusion nuclear energy currently not widely used as a source of electricity?

Fusion reactions have not yet been achieved.
Fusion reactions cannot be controlled.
Fusion reactions require very high temperatures and pressure.
Fusion reaction energy cannot be converted into electricity.

Answer 1

Correct answer: Fusion reactions require very high temperatures and pressure.

Explanation:
- It is not true that fusion reactions have never been achieved — fusion has been produced in laboratories (tokamaks, inertial confinement experiments, and in thermonuclear weapons).
- It is also not true that fusion cannot be controlled — controlled confinement methods (magnetic and inertial) exist, but sustaining them stably and economically is very hard.
- Energy from fusion can in principle be converted to electricity (via heat to drive turbines or by direct conversion); conversion is not the fundamental barrier.

The reason fusion isn’t widely used for electricity today is that achieving the combination of temperature, pressure (or density) and confinement time required for net, sustained, economically useful energy (the Lawson criterion) is extremely difficult. Additional practical challenges include neutron-induced damage to materials, tritium breeding and handling, reactor engineering complexity and cost.