View a list of the worst nuclear meltdowns before 2013

View a timeline of the Chernobyl disaster

The 1986 Chernobyl meltdown, caused by a combination of poor safety design and human error, is the worst nuclear accident in history. At least three dozen people died in the direct aftermath, and experts believe thousands suffered premature cancer deaths from radiation exposure.

Watch an animated, step-by-step reconstruction of the Chernobyl explosion

This video shows how a 1986 safety test at Chernobyl spiraled out of control—leading to a massive rise in temperatures, an explosion and reactor meltdown that produced the largest civilian nuclear disaster in history.

The Chernobyl disaster prompted a sharp decline in public confidence in nuclear power

A Gallup poll from two months after the disaster showed 73% of respondents opposed building a nuclear plant near their homes—up from 45% in 1976. Chernobyl and other nuclear accidents remain in the public consciousness today in debates about nuclear power.

As of 2024, there are 90,000 tons of nuclear waste stored at 100+ sites in 39 states

Over 315,000 bundles of spent nuclear fuel rods are stored in water pools and over 3,800 dry storage casks in concrete vaults above ground. Corrosion from saltwater spray threatens waste containers of reactors near oceans.

Chernobyl pushed the world to create rapid-alert systems for nuclear accidents

In the aftermath of the disaster, nations adopted new agreements requiring immediate international notification of nuclear accidents. They coordinated emergency assistance—efforts led by the International Atomic Energy Agency to prevent future disasters from being concealed when radiation emergencies occur.

Experts argue that nuclear war is more likely than is commonly believed

The podcast highlights that many of the world's roughly 12,000 nuclear weapons—capable of triggering global collapse and nuclear winter—remain on high alert. Experts warn that this status, combined with limited public awareness, makes nuclear war disturbingly plausible.

Explore the decommissioning work at the Fukushima Daiichi Nuclear Power Station

This virtual tour explores the nuclear disaster site, which resulted from a magnitude 9.1 earthquake and tsunami on March 11, 2011, and the various processes underway to remove debris, fuel, and contaminated water.

The Chernobyl disaster released more radioactive material than the Hiroshima bomb.

Over a lifetime, the average American's nuclear power usage creates a hockey puck of nuclear waste

Spent nuclear fuel remains hot and highly radioactive for long periods, requiring submersion in cooling pools before being stored in dry casks and deep underground repositories. The potential recycling of nuclear waste is impeded by security concerns and dangerous reprocessing methods, particularly when obtaining fresh uranium is often easier.

Methods for disposing of nuclear waste include melting it into a liquid to create glass, dumping it into graphite blocks, storing it in lead-lined rooms, and submerging it in deep pools of water.

The 'Elephant's Foot' in Chernobyl is part of the largest documented mass of corium

The nuclear disaster produced around 200 tons of nuclear fuel that mixed with the surrounding melted reactor core materials. As of 2025, corium has been naturally formed four other times in history: once during the Three Mile Island accident and three times at the Fukushima Daiichi plant disaster.

See where the 94 nuclear reactors in the continental US are located

In 2023, these reactors—located in 53 plants across 28 states—prevented 437 million tons of carbon dioxide emissions. A single fingertip-sized uranium pellet generates as much electricity as a ton of coal, enough for one household's annual electricity.

An imbalance in nuclear reactivity factors caused Chernobyl's reactor to explode

The initial explosion resulted from excessive steam pressure that had built up in a runaway manner due to design flaws and violations of safety protocols. Once exposed to atmospheric oxygen, the hot graphite in the control rods underwent a combustion reaction, resulting in a secondary explosion.

Exposure to ionizing radiation from nuclear accidents can damage DNA

The damage can increase the risks of cancer, cataracts, heart disease, and other illnesses based on exposure times and intensities. Contaminated food, water, air, or soil from near nuclear accidents can further prolong one's exposure.

NUKEMAP lets you model the effects of a nuclear detonation anywhere on Earth

The tool was built by Alex Wellerstein, a historian of nuclear technology at the Stevens Institute of Technology in New Jersey. NUKEMAP uses declassified weapons data to calculate blast radius, thermal radiation, fallout patterns, and estimated casualties for any nuclear device dropped on any city. More than 50 million people have used it since its 2012 launch.

Watch an American news report of the Chernobyl disaster

Americans first heard about the Chernobyl nuclear disaster two days after the event, once abnormal radiation was detected in nearby countries. This forced Soviet officials to acknowledge the catastrophe publicly for the first time a few days after it occurred.

Explore illustrative depictions of Chernobyl in comic books

Pieces related to the location since the nuclear disaster have told stories about radioactive vampires and monsters, accounts of bureaucratic corruption and creed, and visual retellings of experiences those in the region lived through before and after the event.

Visualizing the chemistry of nuclear weapons

Nuclear weapons have devastating effects, but the science of how they work is atomically small. There are two main types of nuclear reaction: fission and fusion. The fission bomb produces immense energy by splitting an atom, the result of firing a...

Chernobyl's remaining reactors kept running for 14 years after the explosion

Due to energy shortages in Ukraine, Chernobyl's other undamaged reactors continued operating for years. Units 1 and 2 operated until 1996 and 1991, respectively, while Reactor 3 remained online until December 15, 2000, when Ukraine finally shut down the plant.

Data from 2020 suggests that fossil fuels are the most dangerous and least clean energy sources, causing the most deaths and emitting the most greenhouse gases per unit of energy generated.

Nuclear weapons in WWII

This 14-minute interactive documentary broaches the subject of the human cost of nuclear warfare. Comparing the number of deaths during World War II with the projected deaths of a nuclear exchange, the video can be paused to delve deeper into individual statistics, historical tidbits, and more data that shows the terrible price humanity would pay.

Visualize what happens to atoms during nuclear fission and how the process produces energy

Nuclear fission occurs when an unstable, often massive, atomic nucleus splits into smaller ones—daughter atoms—and releases energy. Within a nuclear reactor, these daughter atoms can collide and combine with neighboring atoms, destabilizing them and triggering a chain reaction of atomic splitting.

Misleading measurements and fear-based reporting often exaggerate radiation risks

Daily exposure to radioactivity is common but occurs in low doses outside of locations near nuclear accidents like Chernobyl and Fukushima. Researchers have detected radiation in tuna, bananas, and the human body due to increasing instrumental sensitivity, not rising concentrations.

The oldest nuclear fission reactor on Earth formed naturally in West Africa about 2 billion years ago, where groundwater enabled atoms in uranium deposits to split, releasing energy.

The first nuclear reactor was built three years after nuclear fission was discovered

After learning that large atomic nuclei release energy upon being split apart, scientists quickly researched how to control the reaction to make electricity. Fusion—combining small atomic nuclei—generates massive energy in stars and hydrogen bombs.

Simulations of atmospheric transport have shown that radioactive material released from potential strikes to US nuclear missile silos would reach everyone in the continental US.

Small modular reactors can provide nuclear power with reduced risks and logistics

Their factory-built design allows them to be quickly installed underground, reducing their exposure to future extreme weather. They can provide power to small towns and major cities with much smaller start-up costs and reduced siting requirements.

Nuclear batteries generate electrical currents using radioactive materials

Rather than using electrochemical reactions to produce the electrons that flow through a circuit, isotopes like nickel-63 undergo beta decay—emitting electrons—which a semiconducting material can absorb to establish a charge imbalance that generates current. Such batteries could provide low-power energy for decades.

For decades, the US has considered building a permanent nuclear waste repository

All nuclear waste would have been stored at Nevada's Yucca Mountain, but the Obama administration indefinitely stalled the project after intense community backlash. Spent fuel is now stored at more than 80 locations in 36 states, raising safety concerns.

Microreactors are 100 to 1,000 times smaller than traditional nuclear reactors but still generate thermal energy for heating or electricity by splitting atomic nuclei.

Russia's invasion of Ukraine has destabilized safety and oversight at Chernobyl

Russian forces cut power and disabled monitoring of the decommissioned nuclear power plant in 2022, endangering operators at Chernobyl. In February 2025, a Russian drone struck the confinement structure—part of broader efforts to pressure Ukraine's energy infrastructure—punching a hole in the containment shell.

In nuclear reactors, water acts as a coolant and moderator, slowing neutrons produced in nuclear reactions so they are more likely to interact with nuclear fuel and generate sustainable energy.

Cold War nuclear tests exposed thousands to atomic blasts

After World War II, nuclear powers conducted thousands of weapons tests. This video pairs archival footage with interviews of veterans who witnessed Pacific test explosions, capturing the scale, shock, and human experience of being near a nuclear detonation.

Nuclear power supplies almost half of US carbon-free energy

As of 2023, nearly 20% of US electricity comes from nuclear power, but most reactors were built from 1971 to 1990. Expansion slowed due to safety concerns, high costs, and competition from natural gas.

Study pinpoints where to hide during a nuclear blast

There’s no surviving the fireball of a nuclear bomb, but beyond that, there are certain spots indoors where you can try avoid the destructive shockwave.

View a photographic timeline of the building of Chernobyl's containment structures

The first structure—built to last 20 to 30 years—served as a covering for the exploded reactor and was built from about 16 million pounds of steel. In 2016, a new containment shell was constructed nearby and rolled onto the previous structure before being finalized in 2019.

During the Cold War, a mid-air fire led to a nuclear bomber crash in Greenland that left a piece of a hydrogen bomb missing to this day.

Explore an interactive map of volcanoes, earthquakes, and tsunamis from 2150 BCE to the present.

Mining of rare earth elements risks leaking radioactive wastewater

The extraction and processing of REEs requires significant amounts of water, and poorly regulated projects can contaminate groundwater with acids and heavy metals. Toxic waste spills have paused work in several US mines since the 1980s, despite growing REE demand.

Like nuclear power, US geothermal power plant construction stalled for decades

Development and investment into geothermal energy took off in the 1960s. However, by the 1980s, companies repeatedly failed to find reservoirs of hot water when exploring new locations, and investors lost interest in the expensive drilling required. By the 2020s, technological advancements had finally helped mitigate exploration risk and expand viable drilling locations.

Limited transparency soon after Chernobyl made it a source of conspiracy theories

Some rumors about the event became perceived as more reliable than the Soviet mass media, which had omitted key information during the early days of uncertainty. The resulting theories included CIA involvement in the disaster, three-headed birds, aliens, and a weaponized earthquake.

View the 10 biggest volcanic eruptions in recorded history

The Mount Tambora eruption in 1815 was the deadliest and released so much sun-blocking ash and gas that 1816 became known as “the year without summer.” The resulting global food shortages are estimated to have killed over 71,000 people.

Learn about ionizing radiation and see the most radioactive places on Earth

The average person is exposed to radiation every day, though most of it is either harmless non-ionizing radiation or ionizing radiation at doses too small to significantly affect an individual. The highest doses of ionizing radiation are received by smokers due to the radioactive polonium and radioactive lead in tobacco products.

Isodope is the world's first nuclear energy influencer

Isabelle Boemeke, a Brazilian fashion model and social media personality, began promoting the benefits of nuclear electricity in 2015. She now debunks common objections to it through her TikTok persona Isodope—which has more than 34,000 followers.

Watch a visualization of a fission chain reaction

When a neutron collides with an atom, it is absorbed into the nucleus. If the resulting nucleus is unstable, it can undergo a series of decays that turn it into a less massive nucleus while releasing energy and other particles.

If, not when: An earthquake is destined to destroy the Pacific Northwest.

When the Cascadia fault line ruptures, it could be North America’s worst natural disaster in recorded history. Read a deep dive into the history of the region and the potential impact of the eventual seismic boom.

The global nuclear arms regime has slowly eroded over the past few decades

Both Russia and the United States have withdrawn from key Cold War-era arms-control pacts. Russia's 2022 invasion of Ukraine marked a turning point, as it suspended its participation in inspections and data-sharing agreements.

A nuclear reactor's characteristic blue light is produced from superluminal particles

When light travels through water, its effective speed is 25% lower than its speed in a vacuum. Just as sound waves bunch up and produce a sonic boom when objects move faster than the speed of sound, particles moving faster than this reduced speed generate a shock wave of light, visible as a blue hue.

Build atomic nuclei to explore their instability and resulting radioactive decay

In this simulation, users can add protons and neutrons to create an atomic nucleus, view its half-life and decay options, and identify patterns in how specific combinations of particles create extremely stable nuclei, from which the nuclear shell model of stability emerged.

More than 500,000 people worked to contain Chernobyl's fallout, many with very little radiation protection.