Fusion Energy Calculator

D-T fusion requires plasma temperatures of 100-150 million Kelvin (about 10 times hotter than the Sun's core) because fusion reactors cannot rely on the gravitational pressure that confines solar plasma. At these temperatures, quantum tunneling through the Coulomb barrier enables fusion at a practical rate.

Tritium is produced by neutron bombardment of lithium: n + Li-6 → He-4 + T + 4.78 MeV. Fusion reactors will be surrounded by a lithium blanket where this breeding reaction occurs. Natural lithium contains 7.5% Li-6, and enriched Li-6 targets can achieve breeding ratios above 1.0, ensuring tritium self-sufficiency.

Ignition occurs when the alpha particles (He-4) produced in D-T fusion deposit enough energy into the plasma to maintain its temperature against all losses, without external heating. This is quantified by the Lawson criterion: the plasma must achieve sufficient density-temperature-confinement time product (nTτ).

On December 5, 2022, the National Ignition Facility achieved fusion ignition for the first time: 2.05 MJ of laser energy delivered to the target produced 3.15 MJ of fusion energy — an energy gain greater than 1. This milestone, while using a pulsed approach different from power plant designs, demonstrated that fusion ignition is physically achievable.

D-T fusion produces no plutonium or long-lived fission products. The primary radioactive waste is the tritium itself (half-life 12.3 years) and the activated structural materials from neutron bombardment. Most fusion waste would be safe within 100 years, compared to thousands of years for fission waste.

ITER (Latin for 'the way') is the world's largest fusion experiment, under construction in Cadarache, France, with contributions from 35 countries. It is designed to produce 500 MW of fusion power from 50 MW of heating — a Q factor of 10. It will not generate electricity but will demonstrate the scientific and technical feasibility of fusion power.

Muon-catalyzed fusion can occur at room temperature, where negatively charged muons replace electrons in hydrogen molecules, shrinking the nuclear separation enough for fusion. However, muons are expensive to produce and each can only catalyze about 300-400 fusions before decaying, making it currently energy-negative overall.

Magnetic confinement (MCF), used in tokamaks like ITER and JET, uses powerful magnetic fields to confine hot plasma in a torus shape. Inertial confinement (ICF), used at NIF, compresses a small fuel pellet with lasers until fusion ignites. Both approaches have demonstrated significant milestones and are pursuing different paths to practical fusion power.

Seawater contains approximately 33 mg of deuterium per liter (1 in 6,400 hydrogen atoms is deuterium). The world's oceans contain about 4.6 × 10¹⁶ kg of deuterium. If D-D fusion were achievable, this represents essentially an inexhaustible fuel supply — enough to power human civilization at current consumption rates for billions of years.