Chain Reaction: A History of Nuclear Power

Marie Curie founded the science of radioactivity that later made nuclear power possible, discovering polonium and radium in 1898. She never worked on a reactor herself, since fission was not understood until after her death, but every stop that follows traces back to the door her work opened.

Enrico Fermi led the team that turned that opened door into an engineered reaction, directing the first self sustaining nuclear chain reaction in 1942. His name marks the hinge between nuclear physics and nuclear power.

Under a squash court beneath the stands of Stagg Field, Chicago Pile-1 went critical on 2 December 1942 under Fermi's direction, the first controlled chain reaction in history. Energy from the atomic nucleus moved that afternoon from theory to engineering, though it would be another twelve years before a reactor lit a light bulb.

On 26 June 1954 the reactor at Obninsk in the Soviet Union sent electricity to a public grid for the first time, a modest five megawatts that opened the era of civilian nuclear power. Calder Hall in England, the next stop on this walk, would claim the larger prize of commercial scale two years later.

Calder Hall in west Cumbria opened in 1956 as the world's first commercial scale nuclear power station and ran for 47 years. Its claim to being first is different from Obninsk's, since Obninsk fed a grid earlier but at a fraction of the output, and the early Magnox reactors at Calder Hall also made military plutonium alongside civilian power.

A cooling malfunction melted part of the reactor core at Three Mile Island in 1979, the most serious accident in American commercial nuclear power. No injuries were recorded and the radioactive release was small, but the accident helped halt new American nuclear construction for a generation.

Reactor 4 at Chernobyl exploded in 1986 during a botched safety test, the worst nuclear accident in history, contaminating large areas of Ukraine, Belarus and beyond. It reshaped nuclear safety practice and public opinion on nuclear power worldwide, a shift this trail cannot walk past.

The 2011 Tohoku earthquake and tsunami knocked out power and cooling at Fukushima Daiichi, melting three reactor cores. Japan idled its reactor fleet and Germany legislated a full exit from nuclear power in response, showing how one accident can redirect energy policy on the far side of the planet.

Plant Vogtle's Units 3 and 4, completed in 2023 and 2024, are the first new American nuclear reactors finished in decades, built years late and far over budget. Their completion made Vogtle the largest nuclear power plant in the country, passing Palo Verde in Arizona, and stands as nuclear power's most recent attempt to answer the questions the earlier stops on this trail raised.