A Nuclear Glossary

Building a world free from nuclear weapons

The world of nuclear disarmament is full of technical terms, jargon and acronyms. We’ve put together a short nuclear glossary which you can use as a handbook for understanding some of the key terms you’ll hear in the movement. Feel free to use the PDF version as a resource wherever it might be useful.

Atomic Weapons Establishment (AWE)

The Atomic Weapons Establishment (AWE) is the research facility of the Ministry of Defence. It is responsible for the design, manufacture and support of UK nuclear weapons. AWE has its headquarters at Aldermaston in Berkshire, England, and has several other sites across the UK.

Read more about AWE here.

Campaign for Nuclear Disarmament (CND)

The Campaign for Nuclear Disarmament (CND) is one of the most important nuclear disarmament organisations in the UK. It was set up in 1958 and launched with a huge public meeting including high-profile supporters such as JB Priestley and Bertrand Russell. It has been campaigning for nuclear disarmament in the UK and elsewhere for more than 60 years. Youth and Student CND is a specialist section of CND.

Read more about CND here.

Comprehensive Test Ban Treaty (CTBT)

In 1996, the Comprehensive Test Ban Treaty (CTBT) opened for signature. The treaty bans all nuclear explosions on earth, including underground tests, which were allowed under an earlier treaty. 196 states have signed, including many of the nuclear weapons states.

Read more about the CTBT here.


Divestment means taking money out of a particular asset, good, interest or industry. When we ask banks, pension funds and other financial institutions to divest from nuclear weapons, we are asking them to stop providing financial services including loans to companies who produce nuclear weapons or support their maintenance. Some banks and pension funds already invest ethically – does yours?

Read more about divestment here (and take action!). 


Trident is based at HMNB Clyde in Western Scotland. There are two facilities here: the base at Faslane, and an Ordnance Depot.

Two of four submarines of the UK’s nuclear deterrent are stationed at Faslane in the River Clyde.

They’ve been there for more than 50 years, despite polling showing that the majority of Scottish people oppose their presence there.

Read more about Faslane here.

Greenham Common

In 1981, women in the UK’s anti-nuclear movement set up a permanent women’s peace camp outside Greenham Common US Airforce Base in Berkshire, where the first US cruise missiles were going to be placed. The camp remained permanently in place till 2000.

Read more about Greenham Common here.

International Campaign to Abolish Nuclear Weapons (ICAN)

The International Campaign to Abolish Nuclear Weapons (ICAN) was launched in 2007 in Australia and has since grown into an international movement. It is an international coalition of civil society organisations and promotes the Treaty on the Prohibition of Nuclear Weapons, which passed into international law in 2021.

Read more about ICAN here.

Mutually Assured Destruction (MAD)

M.A.D. is short for Mutually Assured Destruction. It was a doctrine used particularly during the Cold War in the 20th Century to justify the buildup of nuclear arsenals.

The theory is that a nuclear attack would never happen, because it would provoke nuclear war on such a massive scale that both the original attacker and the retaliator would be destroyed completely. This theory does not account for non-rational actors or accidental use and leads to dangerous, massive buildup of stockpiles.

Read more about MAD here.


Multilateral means many people, countries or groups taking an action together. Multilateral disarmament is the practice of several countries coming together to agree a programme of disarming together. Proponents of multilateralism say that it is safer (it won’t upset the balance of power) and more politically viable.

Read more about multilateral disarmament here.


NATO stands for the North American Treaty Organisation. It’s also known as the North Atlantic Alliance. NATO is an intergovernmental military alliance between some North American and European states. Nuclear deterrence is, in NATO’s own words, ‘a core component of NATO’s overall capabilities.’ NATO states that it is dedicated to arms control, non-proliferation, and ultimately disarmament. But they have recommitted multiple times to interventionist military strategy which sets the mission of disarmament back.

Read more about NATO here.

Non-Proliferation Treaty (NPT)

The Treaty on the Non-Proliferation of Nuclear Weapons, or NPT for short, is a UN treaty that entered into force in 1970 and was extended indefinitely in 1995.

At the time, the Treaty signified a huge step on the road to nuclear disarmament, and was signed by 191 countries. It aims to limit the proliferation of nuclear weapons around the world. Many of the nuclear weapons states, including the UK, have signed the NPT. The NPT includes a commitment to pursue disarmament.

Read more about the NPT here.

Nuclear disarmament

Nuclear disarmament means reducing or completely eliminating nuclear weapons. We believe that this is the only way to prevent nuclear conflict or accidental use, both of which would constitute a humanitarian, political, and international disaster.

Read more about nuclear disarmament here.

Nuclear fission

All matter is composed of atoms, and all atoms have a nucleus at their centre. Nuclei with more particles are heavy, and during fission, the nucleus splits into lighter nuclei. That releases energy. Fission can be induced by shooting a neutron into the nucleus. This process can be used to create a nuclear weapon.

Read more about nuclear fission here.

Nuclear fusion

Nuclear fusion works by fusing lighter nuclei together. When lighter nuclei are exposed to lots of heat, they fuse together and release energy. This is the same process that powers the sun. The first bomb using fusion was tested in 1952. It made a fireball nearly 5km in diameter.

Read more about nuclear fusion here.

Nuclear power

Nuclear power is a way of producing energy using nuclear reactions.

Nuclear fission is a process which occurs when a neutron splits an atom into smaller atoms. In the right conditions this can produce a chain reaction. This process can be controlled in a nuclear reactor, and the heat released from the chain reaction can be used to produce electricity.

Read more about nuclear power here.

Nuclear testing

In the twentieth century, nuclear powers conducted nuclear testing programmes, often in desert regions of Australia, and on atolls (islands) in the Pacific. Tests have taken place in all sorts of atmospheres and places: underground, underwater, on barges, towers, and in the atmosphere. Nuclear testing is designed to test the strength, yield, and capability of a nuclear weapon.

Read more about nuclear testing here.

Nuclear weapon

Nuclear weapons are extremely powerful explosives. The bombs get their energy from either splitting atoms or joining the particles inside them together.

When a nuclear weapon is detonated it releases huge amounts of radiation, which can cause illness and environmental damage for decades after detonation.

Nuclear weapons have two parts: a warhead and a delivery system (usually a missile).

Today there are nine states with nuclear weapons: the USA, Russia, China, France, the UK, India, Pakistan, Israel (probably) and North Korea. 

There are over 4000 nuclear weapons ready to fire and over 9000 more in stockpiles.

Over 90% of an estimated 13,400 warheads are held by the USA and Russia.

Read more about nuclear weapons here.

Nuclear Weapon-Free Zones (NWFZ)

A Nuclear Weapon-Free Zone (NWFZ) is a regional approach to disarming. It aims to strengthen global non-proliferation and work towards global peace and security. Nuclear Weapon-Free Zones are set up by member states and can be as large as whole continents. It doesn’t stop the states involved pursuing nuclear-related technology, but it does mean that the signatories undertake not to manufacture, acquire, test or possess nuclear weapons. States with nuclear weapons undertake not to use or threaten to use nuclear weapons against NWFZs.

Existing NWFZs include the African Nuclear Weapons Free Zone, created by the Treaty of Pelindaba, and the Treaty for the Prohibition of Nuclear Weapons in Latin America and the Caribbean (Treaty of Tlatelolco).

Read more about NWFZs here.

Nuclear Weapons States

Nuclear Weapons States (NWS) are the five states who are defined as having nuclear weapons under the Nuclear Non-Proliferation Treaty (NPT). These are the USA, Russia (the successor to the USSR), the UK, France, and China. India, Pakistan and North Korea possess nuclear weapons but are not counted as NWS under the NPT. Israel is widely believed to possess nuclear weapons but has never publicly acknowledged this, and is not an NWS under the NPT.

Read more about NWS here.

Past nuclear weapons use

Nuclear weapons have only been used twice in war, both in 1945 at the end of the Second World War. The two bombs were dropped on the Japanese cities of Hiroshima and Nagasaki. Between them, these bombs immediately killed around 215,000 people and have continued to cause deaths from radiation ever since they were dropped.

Nuclear weapons were also repeatedly tested in the 20th century.

Read more about the history of nuclear weapons here.


Nuclear proliferation is the process of more nuclear weapons coming into being. Proliferation is about getting more nuclear weapons, but disarming – actually reducing nuclear arsenals – is tied into this as well.

Most concern is given to horizontal proliferation: that’s the spread of nuclear weapons to states which don’t possess them yet. But there is also vertical proliferation – nuclear weapons states increasing the numbers and dispersion of their arsenals.

Read more about proliferation here.

Radioactive Racism

‘Radioactive racism’ refers to the idea that in general, the burden from various aspects of nuclear programmes falls disproportionately on people of colour.

For example, the UK and the US have both conducted extensive nuclear tests on ex-colonial and indigenous territories, and uranium mining is overwhelmingly conducted on indigenous lands. These activities are seldom approved by local communities, and have caused many health and environmental issues for these communities.

Read more about radioactive racism here.

Treaty on the Prohibition of Nuclear Weapons (TPNW)

The TPNW is a UN treaty which outlaws nuclear weapons. Under the TPNW, states may not develop, test, produce, acquire, possess, stockpile, use or threaten to use nuclear weapons, deploy nuclear weapons, or assist other states in doing any of these things. State parties need to make sure none of this is happening on their soil. 

So far, none of the nuclear weapons states have signed or ratified this treaty. The TPNW passed into international law in January 2021.

Read more about the TPNW here.


Trident is the UK’s nuclear weapons system – often called a ‘nuclear deterrent’. It’s made up of 4 submarines, each with 8 missiles. The missiles can carry five warheads.

These warheads are eight times as destructive as the nuclear bomb dropped on Hiroshima, Japan, in 1945, which has killed more than 200,000 people to date.

There is always a Trident submarine on patrol.

Read more about Trident here.


Unilateral means one person, country or group taking an action or decision on its own, without need for consensus among others. Unilateral disarmament therefore means one state disarming its nuclear weapons without other states agreeing to do the same.

Read more about unilateral disarmament here.