Discover the science of the cosmos harnessed on Earth. From the splitting of the atom to the burning of the stars.
Nuclear fission occurs when a heavy atomic nucleus, such as Uranium-235, absorbs a neutron. This makes the nucleus highly unstable, causing it to split into two smaller, lighter nuclei.
This split releases a massive amount of energy in the form of heat and radiation, along with more neutrons. These new neutrons can go on to split other nuclei, creating a controlled chain reaction.
1 pellet of Uranium = 1 ton of coal.
Natural mined uranium contains two main isotopes: ~99.3% U-238 and only ~0.7% U-235. However, U-235 is the critical isotope needed to sustain a nuclear chain reaction.
Most enrichment processes exploit the slight mass difference between U-235 and U-238. The uranium is converted into a gas (uranium hexafluoride) and fed into cylindrical centrifuges.
By spinning the gas at incredibly high speeds, the slightly heavier U-238 is pushed to the outer walls, while the lighter U-235 gathers near the center to be extracted.
A nuclear reactor is essentially a highly sophisticated way to boil water. The fission process generates immense heat inside the reactor vessel.
During the Cold War, the United States and the Soviet Union developed vastly different philosophies for commercial nuclear power.
Water Moderated & Cooled
The US focused on Light Water Reactors. Water acts as both the coolant and the moderator (the substance that slows down neutrons).
Graphite Moderated
The USSR developed the RBMK reactor. It used water as a coolant, but solid graphite blocks as the moderator to slow neutrons.
The intersection of nuclear enrichment capabilities and global security remains a highly volatile issue.
The International Atomic Energy Agency (IAEA) monitors global nuclear activity. The 2015 Joint Comprehensive Plan of Action (JCPOA) set strict limits on Iran's nuclear enrichment to prevent the creation of nuclear weapons.
Currently, Iran claims its program is for peaceful purposes. However, they possess a sufficient amount of enriched uranium for those needs, leading the IAEA to express grave concerns over why Iran continues to enrich more uranium past the JCPOA limits.
Iran has accumulated 440 kg of uranium enriched to 60%. Because of the non-linear "work curve" of centrifuges, this is dangerously close to the 90% required to manufacture a nuclear weapon.
Prior to recent efforts by the US to neutralize their supply, Iran relocated much of its stockpile to Isfahan. Iran has since halted all cooperation with the IAEA. While recent strikes have damaged certain facilities, Iran's deep underground enrichment sites remain a major global concern.
Unlike fission which splits atoms, fusion merges light nuclei (like hydrogen isotopes) together to form a heavier nucleus. This is the exact process that powers the Sun.
No greenhouse gases. The only byproduct is inert helium.
Isotopes can be sourced from seawater, lasting millions of years.
No risk of meltdown. If containment fails, the plasma simply cools and halts.
Scroll horizontally to explore the evolution of nuclear technology.
German chemists Otto Hahn and Fritz Strassmann discover that bombarding uranium with neutrons splits the atom, verified theoretically by Lise Meitner.
Enrico Fermi leads the team that creates the first artificial self-sustaining nuclear chain reaction under the stands of Stagg Field at the University of Chicago.
The Experimental Breeder Reactor I (EBR-I) in Idaho becomes the first nuclear reactor to generate electricity, lighting up four 200-watt lightbulbs.
The Soviet Union connects the AM-1 reactor to the electrical grid in Obninsk, becoming the world's first nuclear power plant to generate electricity for commercial use.
The first full-scale commercial pressurized water reactor (PWR) opens in Pennsylvania, heavily influencing global commercial reactor design.
The National Ignition Facility (NIF) achieves a historic milestone: a fusion reaction that produced more energy than was absorbed by the fuel to initiate it.
A letter outlines a goal to dismantle Iranian enrichment facilities. During April's under-the-radar "Muscat and Rome talks" in Italy, Iran offers to slow enrichment, but the US demands a complete halt.
Israel conducts "Operation Rising Lion," a 12-day air raid campaign targeting nuclear sites. Shortly after, the US intervenes, striking Iranian nuclear sites directly for the first time. Iran officially suspends IAEA cooperation.
The UN reapplies 2015 sanctions, contributing to an economic collapse in Iran by December. The US and Israel coordinate "Operation Epic Fury," a large-scale strike, though deep underground facilities remain a concern.