Glossary

National authority

As required under Article III of the Comprehensive Nuclear-Test-Ban Treaty, the body designated by a Member State to be the national focal point for liaison with the CTBTO and with other Member States.

National Data Centre

A data centre, operated and maintained by a Member State, whose functions may include sending International Monitoring System data to the International Data Centre and/or receiving data and products from the International Data Centre.

National Data Centre (NDC) in a box

A standard software package developed by the International Data Centre, giving the NDCs the capability to receive, process and analyse monitoring data.

National Data Centres

Data centres, operated and maintained by a Member State, whose functions may include sending International Monitoring System data to the International Data Centre and/or receiving data and products from the International Data Centre.

National technical means

Satellites, aircraft, and electronic and seismic monitoring devices used by Member States to survey the activities of other States, including military movements and treaty compliance with regard to possible nuclear testing activities.

NATO

The member countries are committed to maintaining and developing their defense capabilities, to consulting on issues of mutual security concern, and to the principle of collective self-defense. As of March 2008, NATO has 26 members, of which 21 are EU member countries. NATO's members are: Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, the United Kingdom and the United States. Representatives of the 26 NATO legislatures agreed to the accession of three more countries—Croatia, the Former Yugoslav Republic of Macedonia, and Albania—to join NATO at the April 2008 summit. Originally meant to deter Soviet aggression, NATO was created as a collective security agreement. The treaty was signed in Washington on 4 April 1949. It created an alliance of 10 European and two North American independent nations committed to each other's defense.

NDC-in-a-box

National Data Centre (NDC)-in-a-box is a standard software package developed by the International Data Centre, giving the NDCs the capability to receive, process and analyse monitoring data.

Negative security assurances

A pledge by a nuclear weapon state that it will not use nuclear weapons against a non-nuclear weapon state. See also “No first use”.

Network processing

A phase in automatic waveform data analysis, when data from different monitoring stations describing the same event are merged to arrive at a possible location for the detected event.

Neutron bombs

In a neutron bomb, high-energy fusion neutrons are not trapped to sustain fission, but are released in a burst of radiation.  The nuclear explosion is in the kiloton range causing mass casualties, but leaving infrastructure mostly intact and not leaving long-lived radioactive fallout. No country is known to currently deploy such weapons, but the United States, Russia, France, and China are all believed to have developed and tested neutron bombs.

Niels Bohr

Danish physicist born in 1885 who made fundamental contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. He developed the Bohr Theory, which established the first sound description of the behaviour of electrons on atoms. Bohr was also part of the team of physicists who worked on the Manhattan Project, the US government's project that culminated in the development of the nuclear bomb.

NNWS

Same as Non-nuclear weapon state

No First Use

A pledge on the part of a nuclear weapons state not to be the first party to use nuclear weapons in a conflict or crisis. No-first-use guarantees may be made in unilateral statements, bilateral or multilateral agreements, or as part of a treaty creating a nuclear-weapons-free zone.

Noble gas

A chemical element that normally occurs as a gas.  Noble gases are inert and rarely react with other chemicals. Noble gases may occur in nature in a number of isotopes, some of which are unstable and emit radiation. Due to their properties, radioactive isotopes of noble gases, i.e. radionuclide noble gases, are especially useful for monitoring. 

Noble gases

Chemical elements that normally occur as a gas. Noble gases are inert and rarely react with other chemicals. Noble gases may occur in nature in a number of isotopes, some of which are unstable and emit radiation. Due to their properties, radioactive isotopes of noble gases, i.e. radionuclide noble gases, are especially useful for monitoring.

Nocturnal boundary layer

A thin layer of cooler air that forms at the surface over land during the night. This stable layer effectively prevents the ambient winds above this layer from reaching the surface. It is related to infrasound monitoring.

Non-nuclear weapon State

Under the nuclear Non-Proliferation Treaty, this is a state that had not detonated a nuclear device prior to January 1, 1967, (that is, all states other than the United States, the Soviet Union [now Russia], the United Kingdom, France, and China).

Non-nuclear weapon States

Under the nuclear Non-Proliferation Treaty, these are states that had not detonated a nuclear device prior to January 1, 1967, (that is, all states other than the United States, the Soviet Union [now Russia], the United Kingdom, France, and China).

Non-party

A state or entity that is not participating in an agreement, convention, or treaty.

Non-proliferation

Preventing, blocking or halting the spread of nuclear weapons knowledge, fissile material and nuclear related technology.

Non-Proliferation Treaty

See the Treaty on the Non-Proliferation of Nuclear Weapons for further information. The Non-Proliferation Treaty (NPT) is a multilateral treaty on the non-proliferation of nuclear weapons, which entered into force on 5 March 1970. The three pillars of the Treaty are non-proliferation, disarmament and the peaceful use of nuclear technology.

Non-strategic nuclear weapons

Short-range nuclear weapons, such as artillery shells, bombs, and short-range missiles, deployed for use in battlefield operations. Also called tactical nuclear weapons.

North Atlantic Treaty Organization (NATO)

The member countries are committed to maintaining and developing their defense capabilities, to consulting on issues of mutual security concern, and to the principle of collective self-defense. As of March 2008, NATO has 26 members, of which 21 are EU member countries. NATO's members are: Belgium, Bulgaria, Canada, the Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Lithuania, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Turkey, the United Kingdom and the United States. Representatives of the 26 NATO legislatures agreed to the accession of three more countries—Croatia, the Former Yugoslav Republic of Macedonia, and Albania—to join NATO at the April 2008 summit. Originally meant to deter Soviet aggression, NATO was created as a collective security agreement. The treaty was signed in Washington on 4 April 1949. It created an alliance of 10 European and two North American independent nations committed to each other's defense.

NPT

Same as Non-Proliferation Treaty

NTMs

Same as National technical means

Nuclear armed state

Those states that are not States party to the nuclear Nonproliferation Treaty but that are know or assumed to have nuclear weapons.

Nuclear armed states

Those states that are not States party to the nuclear Nonproliferation Treaty but that are know or assumed to have nuclear weapons.

Nuclear deterrent

Same as Deterrence

Nuclear energy

The energy liberated by a nuclear reaction (fission or fusion) or by radioactive decay.

Nuclear explosion

An uncontrolled release of energy produced by a fission or a fusion reaction.

Nuclear explosions

An uncontrolled release of energy produced by a fission or a fusion reaction.

Nuclear explosive device

Nuclear explosive device means any nuclear weapon or other explosive device capable of releasing nuclear energy, irrespective of the purpose for which it could be used. The term includes such a weapon or device in unassembled and partly assembled forms, but does not include the means of transport or delivery of such a weapon or device if separable from and not an indivisible part of it.

Nuclear installation

An installation or location in or at which fresh or irradiated nuclear material or significant quantities of radioactive materials are present. These installations include nuclear-power reactors (including sub-critical and critical assemblies), nuclear research reactors, critical facilities, conversion plants, fabrication plants, reprocessing plants, isotope separation plants and separate storage installations.

Nuclear non-proliferation

Preventing, blocking or halting the spread of nuclear weapons knowledge, fissile material and nuclear related technology.

Nuclear Non-Proliferation Treaty

See the Treaty on the Non-Proliferation of Nuclear Weapons for further information. The NPT is a multilateral treaty on the non-proliferation of nuclear weapons, which entered into force on 5 March 1970. The three pillars of the Treaty are non-proliferation, disarmament and the peaceful use of nuclear technology.

Nuclear power plant

An electrical generating facility using a nuclear reactor as its heat source to provide steam to a turbine generator.

Nuclear power plants

Electrical generating facilities using a nuclear reactor as its heat source to provide steam to a turbine generator.

Nuclear reactor

The heart of a nuclear power plant, the reactor is a device in which the nuclear fission chain reaction is sustained and controlled in a self-supporting nuclear reaction. The varieties are many, but all incorporate certain features, including fissionable material or fuel, a moderating material (unless the reactor is operated on fast neutrons), a reflector to conserve escaping neutrons, provisions for removal of heat, measuring and controlling instruments, and protective devices. Applications for nuclear reactors include power generation, experimental research, production of fissile material for military and commercial applications as well as production of medical isotopes.

Nuclear reactors

The heart of a nuclear power plant, the reactor is a device in which the nuclear fission chain reaction is sustained and controlled in a self-supporting nuclear reaction. The varieties are many, but all incorporate certain features, including fissionable material or fuel, a moderating material (unless the reactor is operated on fast neutrons), a reflector to conserve escaping neutrons, provisions for removal of heat, measuring and controlling instruments, and protective devices. Applications for nuclear reactors include power generation, experimental research, production of fissile material for military and commercial applications as well as production of medical isotopes.

Nuclear Suppliers Group (NSG)

A group of states that cooperate to ensure that nuclear exports are made only under appropriate safeguards, physical protection, nonproliferation conditions, and other appropriate constraints. It first met in 1975 in London. Initially the NSG had seven members, Canada, the Federal Republic of Germany, France, Japan, the USSR, the United Kingdom, and the United States. In 1976-77 membership was expanded to 15. Twelve more nations joined up to 1990. Following the collapse of the Soviet Union, a number of former republics were given observer status as a stage towards future membership. The People's Republic of China joined in 2004. In July 2006, the United States Congress allowed U.S. laws to be amended to accommodate civilian nuclear trade with India. This will exert pressure on the Nuclear Suppliers Group to ease restrictions on exports to India. As of 2008, the NSG had 45 members: Argentina, Australia, Austria, Belarus, Belgium, Brazil, Bulgaria, Canada, China, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Japan, Kazakhstan, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, New Zealand, Norway, Poland, Portugal, Romania, Russia, Slovakia, Slovenia, South Africa, South Korea, Spain, Sweden, Switzerland, Turkey, Ukraine, the United Kingdom and the United States.

Nuclear umbrella

Also known as extended deterrence, the term describes security derived through military protection from a nuclear power. A country protected from potential enemies by the nuclear weapons of an ally is said to be under a nuclear umbrella. By coming under a nuclear umbrella, countries allied with a nuclear weapon state hope to deter nuclear attack or threat from other countries.

Nuclear use doctrine

The fundamental principles by which military forces or political leaders guide their decisions regarding the use of nuclear weapons.

Nuclear weapon

A device consisting of a nuclear explosive and a delivery system that releases nuclear energy in an explosive manner as the result of nuclear chain reactions involving the fission or fusion or both, of atomic nuclei.

Nuclear weapon state

China, France, the Soviet Union/Russian Federation, the United Kingdom, and the United States. These are the five states. As defined by Article IX, paragraph 3 of the nuclear Nonproliferation Treaty, that detonated a nuclear device prior to 1 January 1967.

Nuclear weapon states

China, France, the Soviet Union/Russian Federation, the United Kingdom, and the United States. These are the five states. As defined by Article IX, paragraph 3 of the nuclear Nonproliferation Treaty, that detonated a nuclear device prior to 1 January 1967.

Nuclear weapons

Devices consisting of a nuclear explosive and a delivery system that release nuclear energy in an explosive manner as the result of nuclear chain reactions involving the fission or fusion or both, of atomic nuclei.

Nuclear-weapon-free country

Several countries have declared their nuclear-weapon-free status. However, Mongolia's single state nuclear free status is the only one which was endorsed by the United Nations General Assembly. For example, New Zealand established a Nuclear Free Zone Act. Japan also has the three non-nuclear principles, but they are not legally binding.

Nuclear-Weapon-Free Southern Hemisphere and Adjacent Areas

Current existing nuclear-weapon-free zones are all located in the Southern Hemisphere. Since 1996, the United Nations General Assembly has adopted a resolution calling for the creation of a Nuclear-Weapon-Free Southern Hemisphere and adjacent areas.

Nuclear-Weapon-Free Status of Mongolia

 UN General Assembly Resolution 3261 adopted on 9 December 1974, recognized the possibility that a single-state nuclear-weapon-free zone could be established. The Mongolian government declared itself a single-state nuclear-weapon-free zone at the 47th session of the UN General Assembly in 1992. The 55th session of the UN General Assembly (2000) adopted Resolution 55/33S on "Mongolia's international security and nuclear weapon free status”. Like other existing NWFZs, Mongolia's single-state NWFZ, which prohibits nuclear testing, is recognized internationally and contains verification and compliance mechanisms. Although the Law of Mongolia on its NWFZ status provides for verification and compliance mechanisms, the only mechanisms that have been established are Mongolia's comprehensive safeguards agreement with the IAEA and the additional protocol to that agreement.

Nuclear-Weapon-Free Zone

A geographical area in which nuclear weapons are not allowed to be built, possessed, transferred, deployed or tested.

Nuclear-Weapon-Free Zone Protocol

Provides for the obligations and rights of non-parties to the zone and of the nuclear weapon states with reference to those states that are party to the NWFZ and the region covered. Protocols may include assurances by the NWS not to use or threaten to use nuclear weapons against contracting parties within a NWFZ.

NWFZ

Same as Nuclear-Weapon-Free Zone

NWS

Same as Nuclear weapon State