Can Nuclear Fusion Reactors Save The World?

What It Covers

Stuff You Should Know examines nuclear fusion as a potential global energy solution, covering the ITER project in France, the physics of plasma containment, two primary reactor designs — magnetic and inertial confinement — and the key technical barriers preventing commercially viable fusion power from reaching the grid.

Key Questions Answered

• •Energy output ratio: Nuclear fusion produces 4 times more energy per kilogram of fuel than fission and 10 million times more than coal. This ratio makes fusion the most energy-dense power source humans have identified, meaning far less fuel is needed to generate electricity at civilization-scale output.
• •ITER project scale: The International Thermonuclear Experimental Reactor in Aix-en-Provence requires 70 megawatts of input power to initiate a reaction but is designed to yield 500 megawatts of output — a net gain of 430 megawatts. The $50 billion multinational project, delayed to 2034, represents the current benchmark for fusion viability.
• •Plasma containment via Tokamak design: The Russian-developed Tokamak — a donut-shaped chamber wrapped with electromagnetic rings — remains the standard containment method. Alternating electromagnetic fields trap plasma heated to 100 million Kelvin, roughly six times hotter than the sun's core, compensating for Earth's lack of gravitational pressure.
• •Fuel progression from tritium to deuterium: Current reactors use deuterium-tritium reactions, but tritium is radioactive and sourced from rare lithium. The target fuel cycle is deuterium-deuterium reactions, extractable from seawater in near-limitless quantities and non-radioactive at any stage, eliminating the primary waste and scarcity concerns of the current approach.
• •Inertial confinement via lasers: Lawrence Livermore's National Ignition Facility focuses 192 laser beams delivering 1.8 million joules onto a pea-sized deuterium-tritium pellet inside a 10-meter chamber. This approach bypasses electromagnetic containment entirely and is projected to yield 50 to 100 times more energy output than input, exceeding the ITER ratio.