Nuclear fuel

History of nuclear energy

History of nuclear energy

To explain the history of nuclear energy, we could distinguish three major stages:

  • Scientific physical and chemical studies of the elements.

  • The development of the nuclear bomb during World War II.

  • Use of nuclear energy in the civil sphere.

Scientific studies encompass this entire period from when the first Greek philosophers began to define atoms, until the development of the first nuclear bomb. In this process, different scientists discover the presence of electrons, neutrons, and protons

In this period, the first atomic theories are established, and radioactivity is discovered.

During World War II, the US drove the first nuclear bomb. Seeing the danger of nuclear weapons, treaties began to be established to regulate their development and promote nuclear energy in the civil sphere. 

At this time, the first nuclear power plants for electricity generation began to appear.

Who discovered the atom?

Democritus of Abdera was the first in history to speak of the concept of the atom.

The name of nuclear energy comes from “nucleus”. Specifically, it refers to an atom’s nucleus, so sometimes people use the atomic energy’s concept.

Throughout history, various scientists have made their research and progress. We list the most important discoveries:

  1. The Greek philosopher Democritus of Abdera was the first to define the atom: the smallest constituent part of the matter.

  2. John Dalton affirmed that the elements were formed from certain combinations of atoms and that all the atoms of the same element were identical. 

  3. In 1897, JJ Thompson announced the discovery of a negatively charged particle that he called the electron.

  4. In 1896, the French physicist Antoine-Henri Becquerel discovered natural radioactivity by chance.

  5. Frédèric Joliot and Irene Curie were the discoverers of artificial radioactivity. They were the ones who realized that it was possible to obtain radioactivity artificially.

  6. Rutherford proposes the atomic model that bears his name: Rutherford's atomic model. According to this model, the atom has a positive nucleus and particles with negative charges orbit around it.

  7. Max Planck formulated that small individual units emitted energy. He discovered a universal constant known as Planck's constant.

  8. Einstein proposes the famous theory of relativity.

  9. Danish physicist Niels Böhr proposes Böh's atomic model. In this model, the atom is divisible. This characteristic opens doors to specific energy manifestations and nuclear energy.

  10. James Chadwick, in 1932, discovered the neutron. With his discovery, Chadwick obtained a "projectile" of ideal characteristics to cause nuclear reactions.

When was nuclear energy discovered? 

In 1938, a team of German researchers discovered nuclear fission. At that time, we were on the threshold of the Second World War.

The reaction that is currently used in all nuclear power stations to produce electricity. The team consisted of Otto Hahn, Fritz Strassmann, Lisa Meitner, and Otto Frisch.

History of nuclear energyOtto Hahn and Lise Meitner found an intermediate atomic number in a uranium sample bombarded with neutrons.

They deduced that by bombarding enriched uranium with neutrons, the uranium atom captured a neutron and split into two fragments. Besides, the reaction emitted a large amount of energy.

Who invented nuclear power?

Enrico Fermi was the first to build a nuclear reactor (Chicago Pile-1). 


Chicago Pile-1 (CP-1) is the world's first artificial nuclear reactor. It was built in 1942 at the University of Chicago. The director of the project was Enrico Fermi. It was part of the work that later became the basis of the Manhattan Project.

The purpose of CP-1 reactor design was to test the possibility of a controlled nuclear chain reaction. They wanted it to produce plutonium for the bomb.

Who invented the atomic bomb?

The theoretical physicist J. Robert Oppenheimer is the inventor of the atomic bomb. He was the director of the Manhattan Project, where the nuclear bomb was developed.

What was the Manhattan Project?

The Manhattan Project was named the top-secret operation (from 1942 to 1946) led by the United States. The project counted on Canada and the United Kingdom’s help. This project allowed the United States to develop the atomic bomb during World War II.

In 1939, at the beginning of World War II, Albert Einstein warned President Franklin D. Roosevelt with a letter. It was possible to obtain nuclear chain reactions and the possibility that the nazis could get the nuclear bomb.

Roosevelt increased research on the national security implications of nuclear fission and created the Manhattan Project. Several exceptional nuclear physics worked on it. Oak Ridge was the production site for the Manhattan Project.

On July 16, 1945, the plutonium atomic bomb’s first test was successfully carried out in the Alamogordo desert(New Mexico).

The uranium and plutonium atomic bombs were ready at the same time.

When was the atomic bomb dropped?

On August 6, 1945, the USA dropped Little Boy bomb Hiroshima; three days later, on August 19, the United States dropped Fat Man Nagasaki.

History of nuclear energyHistory of nuclear energy

After the detonation on Hiroshima, Einstein commented: "I should burn the fingers with which I wrote that first letter to Roosevelt."

What happened to nuclear energy after World War II?

After World War II, it existed many complex issues around the military and civil uses of nuclear energy. Consequently, it was imperative to set rules and laws to regulate it at all levels. 

In 1946, the United States presented a plan at the United Nations. The project consisted of a gradual liberation of secrets, factories, and nuclear bombs. The United States proposed to give up all this information in exchange for international control and inspection. The former Soviet Union objected, and it was a failure.

At the same time, the Soviet Union built the H-Bomb. The destructive capacity of this bomb was much more significant. The H-bomb combines uranium nuclei with nuclear fusion.

The Soviets finished the H-bomb in 1952. Its power turned out to be 700 times that of the Hiroshima atomic bomb.

Nuclear energy for peaceful uses, electricity generation

The international community projected a series of Besidesconferences about the technical nature of nuclear energy’s peaceful uses.

Taking advantage of the new situation, US President Eisenhower then presented his international cooperation program "Atoms for Peace" at the United Nations. 

The speech proposed an agreement between the great powers to stop and reduce the manufacture of nuclear weapons. In addition, the creation of regulatory bodies was favored.

Definitive Nuclear Non-Proliferation Treaty

In 1967, the IAEA started to work on the Nuclear Non-Proliferation Treaty and its contents. The signatory countries agreed not to transfer nuclear weapons or collaborate in their manufacture, and they undertook to establish the necessary safeguards for their compliance.

The development of nuclear energy was promoted by the interest aroused about the production of electricity using this energy source.

Civil nuclear renaissance

Throughout the 1960s and 1970s, various countries launched several nuclear programs. Today, there are more than 450 operational nuclear reactors around the world, generating electricity. The most are using enriched uranium as nuclear fuel.

In the early 2000s, the nuclear industry expected a nuclear renaissance. This development was due to concerns about carbon dioxide emissions.

It is currently expected for each country to require design changes to satisfy the various national regulatory bodies.

What are the worst nuclear accidents in history?

The worst nuclear disasters in the world so far are the following:

  • The explosion of the Chernobyl nuclear power plant, Ukraine.

  • Earthquake and tsunami in central Fukushima, Japan.

  • Kyshtymin, Russia.

  • Goiânia, Brazil.

  • Radioactive particle emission in Three Mile Island Nuclear Power Plant, USA.

Publication Date: July 13, 2011
Last Revision: September 29, 2020