What is a nuclear bomb?
A Nuclear Bomb is an explosive device that utilises the huge energy potential of nuclear fission (atomic bomb) or a combination of fission and nuclear fusion (hydrogen bomb) to deliver a bomb with great destructive force.
The destructive force of a nuclear bomb is such that a single bomb can provide the force which would require an equivalent of over 1m ton of TNT to replicate. The destruction is not limited to the initial blast, nuclear bombs also release huge amounts of radiation, causing radiation sickness and links to further illnesses.
KEY TAKEAWAYS - A Nuclear Bomb is an explosive device that uses the power of nuclear energy to generate a destructive force. - There are two main types of nuclear bombs; the A-Bomb (Nuclear Fission only) and H-Bomb (Nuclear Fission and Nuclear Fusion). - Hiroshima and Nagasaki, killing 129,000 and 226,000 people respectively, are the only nuclear bombs to be deployed in warfare. - 13 Countries openly admit to having nuclear bombs at their disposal. Israel are believed to have nuclear bombs but have never openly admitted to having so.
Nuclear Explosion Power Comparison
How does a nuclear bomb work?
There are a number of types of nuclear bombs with the two main categories being nuclear fusion bombs and nuclear fission bombs. Although all types of nuclear bombs include nuclear fission, those that use only nuclear fission are referred to as atomic bombs (A-Bombs).
There are a couple of designs of A-Bombs (gun-type and implosion-type) but the basic principal is that uranium or plutonium is forced to go supercritical creating a nuclear chain reaction creating a huge amount of energy which is reported to be 15,000-20,000 times that of TNT. The critical function of the nuclear bomb is to ensure that there is a significant fraction of the fuel before the bomb destroys itself.
Fission reactions create fission products which can leave a great amount of radioactive contamination which is often referred to as a nuclear fallout. This is further enhanced by the free nuclei that are realised which can collide into surrounding materials making those radioactive also.
The second major type of nuclear bomb is nuclear fusion bombs often referred to as Hydrogen Bombs (H-Bombs) or Thermonuclear Bombs. Almost all nuclear weapons deployed today adopt a thermonuclear design due to their efficiency.
The design of a Thermonuclear Bomb utilises a multi-stage reaction with nuclear fission (stage one) being utilised to start a nuclear fusion reaction (stage two) which creates high-speed neutrons that can induce fission in depleted uranium which would otherwise not be prone to fission. When detonated about half of the blast energy comes from depleted uranium as a result of stage two.
Nuclear Fusion does not create such a nuclear fallout as seen with nuclear fission. However, as the design includes nuclear fission as part of their primary stage thermonuclear bombs can leave a similar fallout to a fission only A-Bomb.
How many nuclear bombs have been used?
Most people will immediately think of pictures and video from August 1945 when the US dropped two nuclear bombs over the Japanese cities of Hiroshima and Nagasaki killing 129,000 and 226,000 people respectively. The nuclear bombings were agreed by the UK as per the Quebec Agreement and a gun-type nuclear fission bomb call “Little Boy” was dropped over Hiroshima on 6th August with an implosion-type “Fat Man” being dropped on Nagasaki 3 days later.
These are the only two nuclear bombs that have been dropped in warfare. There have been many instances of nuclear bomb testing with the Tsar Bomba being the largest weapon ever tested by the USSR in 1961 at the height of the Cold War utilising a three-stage design approach. Most bombs now are a lot smaller than this for practicality reasons.
Nuclear Bomb Countries
This is not as easy a question to answer as it should be. There are four categories of Countries that have nuclear weapons being; Treaty on the Non-Proliferation of Nuclear Weapons (NPT) States, States known to have nuclear weapons, States believed to have nuclear weapons and those in the NATO nuclear sharing programme.
The mix of Countries includes China, France, Russia, UK, US in the NPT. India, North Korea and Pakistan in the ‘known’. Israel are believed to have Nuclear Weapons but have never admitted so. Then Belgium, Germany, Italy, The Netherlands and Turkey form the NATO nuclear sharing programme.
The UK, US, Russia, China, France, India and North Korea have also undertaken H-Bombs testing to produce a thermonuclear bomb. However, It is disputed whether India achieved a multi-stage reaction as part of their testing programme and there is major controversy and doubt over the claims of North Korea in 2016.