Nuclear North Korea

North Korea is suspected to have conducted its fifth and largest nuclear test to date. A seismic tremor was detected in an area around the country’s main nuclear test site.

Nuclear facilities

Sources: Union of Concerned Scientists; Atomic Heritage Museum; National Nuclear Security Administration; Global Security; Nuclear Threat Initiative; Federation of American Scientists; Center for Nonproliferation Studies; South Korean defence ministry; International Atomic Energy Acency; World Nuclear Association; Reuters
By Simon Scarr, Christian Indon, Wen Foo | REUTERS GRAPHICS

North Korea claims the country has previously tested a miniaturised hydrogen bomb, also known as a thermonuclear device, a step up from the earlier and less powerful atomic bombs they have tested. However, outside experts are skeptical and believe the bomb could be a “boosted” device, and not a full-fledged H-bomb.

Plutonium device

Explosive charges compress the plutonium fissile core causing fission to occur, producing an explosion.

Uranium device

Known as a gun-type fission device, it fires a mass of uranium into another to create a supercritical mass.

Boosted device

Hydrogen isotopes are incorporated in the fissile core to accelerate fission upon detonation.

Hydrogen isotopes are incorporated in the fissile core to accelerate fission upon detonation of the device.

Thermonuclear

The most advanced warhead. A primary component is detonated which triggers a secondary fusion explosion.

The most advanced warhead. A primary component is detonated which triggers a secondary explosion.

North Korea claims the country has previously tested a miniaturised hydrogen bomb, also known as a thermonuclear device, a step up from the earlier and less powerful atomic bombs they have tested. However, outside experts are skeptical and believe the bomb could be a “boosted” device, and not a full-fledged H-bomb.

Plutonium device

Explosive charges compress the plutonium fissile core causing fission to occur, producing an explosion.

Uranium device

Known as a gun-type fission device, it fires a mass of uranium into another to create a supercritical mass.

Boosted device

Hydrogen isotopes are incorporated in the fissile core to accelerate fission upon detonation of the device.

Hydrogen isotopes are incorporated in the fissile core to accelerate fission upon detonation.

Thermonuclear

The most advanced warhead. A primary component is detonated which triggers a secondary fusion explosion.

underground testing

A vertical shaft is drilled to a depth of 600 to 2,500ft, depending on the yield of the device. After the device is lowered, layers of material such as sand and tar seal the hole along with a diagnostics canister to record data.

Milliseconds after detonation, temperatures of several million degrees and high pressure vaporise the nearest rocks.

A melt cavity is produced and molten rock begins to harden into a glass puddle on the cavity’s floor. Fracturing occurs.

As the pressure in the cavity decreases, rubble fills the cavity. This can take seconds to as long as hours.

This 'rubble chimney' may extend to the ground surface, forming a subsidence crater.

Sources: Union of Concerned Scientists; Atomic Heritage Museum; National Nuclear Security Administration; Global Security; Nuclear Threat Initiative; Federation of American Scientists; Center for Nonproliferation Studies; South Korean defence ministry; International Atomic Energy Acency; World Nuclear Association; Reuters
By Simon Scarr | REUTERS GRAPHICS

Nuclear testing is part of a process that moves Pyongyang closer to miniaturising nuclear warheads to mount on intercontinental ballistic missiles. North Korea has well over 1,000 missiles of various ranges.

North Korea’s estimated ballistic missile ranges

Nuclear testing is part of a process that moves Pyongyang closer to miniaturising nuclear warheads to mount on intercontinental ballistic missiles. North Korea has well over 1,000 missiles of various ranges.

Sources: Union of Concerned Scientists; Atomic Heritage Museum; National Nuclear Security Administration; Global Security; Nuclear Threat Initiative; Federation of American Scientists; Center for Nonproliferation Studies; South Korean defence ministry; International Atomic Energy Acency; World Nuclear Association; Reuters
By Simon Scarr, Christian Indon, Wen Foo | REUTERS GRAPHICS