The Preparatory Commission for
the Comprehensive Nuclear-Test-Ban Treaty Organization
The Preparatory Commission
The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO Preparatory Commission) is an international organization established by the States Signatories to the Treaty on 19 November 1996. It carries out the necessary preparations for the effective implementation of the Treaty, and prepares for the first session of the Conference of the States Parties to the Treaty.
The Preparatory Commission consists of a plenary body composed of all the States Signatories, and the Provisional Technical Secretariat (PTS). Upon signing the Treaty, a State becomes a member of the Commission. Member States oversee the work of the Preparatory Commission and fund its activities.
The Commission’s main task is the establishment of the 337 facility International Monitoring System and the International Data Centre, and the development of operational manuals, including for on-site inspections.
The Comprehensive Nuclear-Test-Ban Treaty (CTBT) is a cornerstone of the international regime on the non-proliferation of nuclear weapons and an essential foundation for the pursuit of nuclear disarmament. Its total ban of any nuclear weapon test explosion will constrain the development and qualitative improvement of nuclear weapons and end the development of advanced new types of these weapons.
The Comprehensive Nuclear-Test-Ban Treaty was adopted by the United Nations General Assembly, and was opened for signature in New York on 24 September 1996. It has achieved strong worldwide support.
The Treaty will enter into force after it has been ratified by the States listed in its Annex 2. These 44 States formally participated in the 1996 session of the Conference on Disarmament, and possess nuclear power or research reactors.
History of the Comprehensive Nuclear-Test-Ban Treaty (CTBT)
Arms control advocates had campaigned for the adoption of a treaty banning all nuclear explosions since the early 1950s, when public concern was aroused as a result of radioactive fall-out from atmospheric nuclear tests and the escalating arms race.
Over 50 nuclear explosions were registered between 16 July 1945, when the first nuclear explosive test was conducted by the United States at Alamogordo, New Mexico, and 31 December 1953.
Prime Minister Nehru of India voiced the heightened international concern in 1954, when he proposed the elimination of all nuclear test explosions worldwide.
However, within the context of the cold war, scepticism in the capability to verify compliance with a comprehensive nuclear-test ban-treaty posed a major obstacle to any agreement.
Partial Test Ban Treaty, 1963
Limited success was achieved with the signing of the Partial Test Ban Treaty in 1963, which banned nuclear tests in the atmosphere, underwater and in space. However, neither France nor China, both nuclear weapon States, signed the PTBT.
Non-proliferation Treaty, 1968
A major step towards the non-proliferation of nuclear weapons came with the signing of the Nuclear Non-proliferation Treaty (NPT) in 1968. Under the NPT, non-nuclear weapon States were prohibited from, inter alia, possessing, manufacturing or acquiring nuclear weapons or other nuclear explosive devices. All signatories were committed to the goal of nuclear disarmament.
Negotiations for the CTBT
Given the political situation prevailing in the subsequent decades, little progress was made in nuclear disarmament until 1991. Parties to the PTBT held an amendment conference that year to discuss a proposal to convert the Treaty into an instrument banning all nuclear-weapon tests; with strong support from the UN General Assembly, negotiations for a comprehensive test-ban treaty began in 1993.
Adoption of the CTBT, 1996
Intensive efforts were made over the next three years to draft the Treaty text and its two annexes, culminating in the adoption of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) on 10 September 1996 by the United Nations General Assembly in New York.
The CTBT, which prohibits all nuclear test explosions, was opened for signature in New York on 24 September 1996, when it was signed by 71 States, including the five nuclear-weapon States.
Summary of the Comprehensive Nuclear-Test-Ban Treaty (CTBT)
The Comprehensive Nuclear-Test-Ban Treaty bans all nuclear explosions. It comprises a preamble, 17 articles, two annexes and a Protocol with two annexes.
The preamble outlines the significance of the Treaty.
Article I stipulates the basic obligations of the Treaty, and prohibits State parties from carrying out any nuclear explosion.
Article II provides for the establishment of the Comprehensive Nuclear-Test-Ban Treaty Organization in Vienna to ensure the Treaty's implementation as well as providing a forum for consultation and cooperation.
Article III focuses on national implementation measures.
Article IV elaborates on the global verification regime to monitor compliance with Treaty provisions. The regime is to comprise a global network of monitoring stations (the International Monitoring System), an International Data Centre in Vienna, a consultation and clarification process, On-site Inspections, and confidence-building measures.
Article V outlines measures to redress a situation which contravenes CTBT provisions and to ensure compliance with the Treaty.
Article VI deals with the settlement of disputes that may arise concerning the application or the interpretation of the Treaty.
Article VII is concerned with amendments to the Treaty.
Article VIII stipulates when a review of the Treaty will take place after its entry into force.
Article IX states that the Treaty is of unlimited duration.
Article X deals with the status of the Protocol and the annexes.
Article XI is concerned with signature of the Treaty.
Article XII deals with ratification of the Treaty.
Article XIII is about accession to the Treaty.
Article XIV is about the Treaty's entry into force. This will take place 180 days after the 44 States listed in Annex 2 to the Treaty have all ratified.
Article XV specifies that the Treaty shall not be subject to reservations.
Article XVI refers to the Depositary of the Treaty.
Article XVII deals with the authenticity of Arabic, Chinese, English, French, Russian and Spanish Treaty texts.
Annex 1 to the Treaty lists States by geographical regions for the purposes of elections to the Executive Council.
Annex 2 to the Treaty lists the 44 States that must ratify the Treaty for it to enter into force.
Protocol Part I describes the functions of the International Monitoring
System (IMS) and the International Data Centre (IDC).
Protocol Part II sets up the procedures for on-site inspections.
Protocol Part III deals with confidence-building measures.
Annex 1 to the Protocol lists the facilities comprising the IMS network.
Annex 2 to the Protocol lists the characterization parameters for IDC standard event screening.
Comprehensive Nuclear-Test-Ban Treaty (CTBT)
•The Comprehensive Nuclear-Test-Ban Treaty is open for signature by all States prior to entry into force.
•The steps leading to signature of the Treaty are as follows:
1.A Government decides to sign the Treaty, and who will sign it on behalf of the State.
2.Any representative other than the Head of State or Government or the Minister for Foreign Affairs will need to possess or be issued with full powers to sign the Treaty. These powers can be delegated by the Head of State or Government or the Minister for Foreign Affairs.
3.Signature is accomplished when the authorized representative of a State signs the Treaty at the United Nations Headquarters in New York.
•The Chief of the Treaty Section of the Office of Legal Affairs of the United Nations should be contacted in order to make an appointment to sign the Treaty.
•Ratification of the Comprehensive Nuclear-Test-Ban Treaty is a two-step process, which has to be secured first at the national level and then at the international level.
•The CTBT stipulates that it should be ratified according to a State's constitutional processes.
•The ratification process differs from State to State. Approval is generally required by the legislature or the executive of a State, or both.
•Advice on national constitutional requirements and the domestic procedures necessary to ratify the Treaty can be obtained from the responsible government office, usually the Ministry of Foreign Affairs.
•The instrument of ratification must be signed either by the Head of State or Government or the Minister for Foreign Affairs or by an official with full powers to sign the instrument. This signature validates the instrument of ratification.
•Unsigned instruments of ratification in the form of notes verbales are not acceptable.
•The instrument of ratification must indicate the title of the person who has signed it and its date and place of issue.
•The instrument of ratification should bear the name of the Treaty.
•It must contain an unambiguous expression of the will of the Government, acting on behalf of the State, to recognize itself as being bound by the Treaty and to implement its provisions.
•The ratification process is completed by depositing the instrument of ratification with the Secretary-General of the United Nations. This indicates the consent of the State to be bound by the Treaty.
•The deposit of an instrument of ratification at United Nations Headquarters is carried out:
- either by the representative of the Government concerned delivering the instrument of ratification to the Secretary-General, or to his representative (the Legal Counsel or the Chief of the Treaty Section of the Office of Legal Affairs);
- or by sending the instrument of ratification to the Secretary-General by mail.
Entry into Force
•The CTBT will enter into force 180 days after it has been ratified by the 44 Sates listed in its Annex 2.
•These 44 States all formally participated in the 1996 session of the Conference on Disarmament, and possess either nuclear power or research reactors.
Overview of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization Establishment
•The Preparatory Commission for the Comprehensive
Nuclear-Test-Ban Treaty Organization (CTBTO Preparatory Commission) was established on 19 November 1996 by a Resolution adopted by the Meeting of States Signatories at the United Nations in New York.
•The Preparatory Commission was established to prepare for the Treaty's entry into force. This will occur 180 days after the Treaty has been ratified by the 44 States listed in its Annex 2. Following the first conference of the States Parties to the CTBT, the Preparatory Commission will cease to exist and the CTBTO will be established.
•The Preparatory Commission is a cost-effective, results-oriented international organization financed by the CTBT States Signatories.
•It has a strong technical focus, with some 80 per cent of its budget dedicated to the establishment of the global verification regime.
•In June 2000, a relationship agreement between the United Nations and he Preparatory Commission was signed and entered into force.
•The Preparatory Commission consists of the States Signatories. Upon signing the CTBT, a State becomes a member of the Commission.
•The Preparatory Commission consists of two organs: A plenary body composed of all the States Signatories (also know as the Preparatory Commission), and the Provisional Technical Secretariat (PTS).
•Ambassador Volodymyr Yelchenko, Permanent Representative of Ukraine, is the Chairperson of the Preparatory Commission for 2006.
•The PTS started its work in Vienna on 17 March 1997 under Executive Secretary Wolfgang Hoffmann. As of 1 August 2005, Tibor Tóth is the Executive Secretary of the Preparatory Commission.
•Only nationals of States Signatories may serve in the Provisional Technical Secretariate.
•The activities of the Preparatory Commission are:
1.Establishment of a global verification regime to monitor compliance with the comprehensive ban on explosive nuclear testing.
2.Promotion of Treaty signature and ratification for early entry into force.
•States Signatories participate actively in the work of the policy-making organs of the Preparatory Commission, as well as provide the necessary financial backing.
•Payment of assessed contributions is an important barometer to gauge this commitment and support. As of 19 October 2006 the collection rate for 2005 stands at 88% and for 2006 at 77%.
•The budget for 2006 is $51,804,400 and €44,421,
The Structure of the CTBTO Preparatory Commission
The Preparatory Commission comprises two main organs:
•A plenary body of all the States Signatories, which is also known as the Preparatory Commission.
•Ambassador Ana Teresa Dengo, Permanent Representative of Costa Rica is the Chairperson of the Preparatory Commission for 2007.
•The Provisional Technical Secretariat.
•Tibor Tóth of Hungary is the Executive Secretary of the Preparatory Commission and the head and chief administrative officer of the Provisional Technical Secretariat.
The plenary body has three subsidiary bodies:
1.Working Group A, which deals with budgetary and administrative matters, such as the annual budget, financial and staff regulations and rules, and legal issues.
Ambassador Abdulkadir Bin Rimdap of Nigeria is the Chairperson of Working Group A.
2.Working Group B, which deals with the examination of verification issues.
Dr. Hein Haak of The Netherlands is the Chairperson of Working Group B.
Both Working Groups make proposals and recommendations for consideration and adoption by the Preparatory Commission.
3.An Advisory Group, which advises the Commission and its subsidiary bodies on financial, budgetary and associated administrative matters. The Advisory Group consists of experts from States Signatories, who are of recognized standing and experience in financial matters at the international level.
Mr. André Gué of France is Chairperson of the Advisory Group.
The Provisional Technical Secretariat
•The Provisional Technical Secretariat (PTS) of the Preparatory Commission started work in Vienna on 17 March 1997.
•The PTS is multinational in composition. As at 9 October 2006, it comprised 259 staff members from 65 States Signatories.
An Overview of the Verification Regime
•In order to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty, a global verification regime is being established.
•This is the main task of the Preparatory Commission, which needs to ensure that the regime is operational by the time the Treaty enters into force.
The verification regime consists of the following elements:
An International Monitoring System Consultation and clarification process
The International Monitoring System comprises facilities for seismological, hydroacoustic, infrasound and radionuclide monitoring including certified laboratories, and respective means of communication. This system is supported by the International Data Centre.
The International Monitoring System (IMS)
•The International Monitoring System (IMS) comprises a network of 321 monitoring stations and 16 radionuclide laboratories that monitor the earth for evidence of nuclear explosions in all environments. The system uses four verification methods, utilizing the most modern technology available.
•Seismic, hydroacoustic and infrasound stations are employed to monior the underground, underwater and atmosphere environments, respectively.
•Radionuclide stations can detect radioactive debris from atmospheric explosions or vented by underground or underwater nuclear explosions.
Location of stations
•The establishment of the IMS poses engineering challenges unprecedented in the history of arms control, with many stations located in remote and inaccessible parts of the globe.
Certification of IMS stations
•Once established and certified as meeting all technical requirements, monitoring stations are provisionally operated by local institutions under contracts with the PTS.
The International Data Centre (IDC)
The IMS is supported by the International Data Centre, which is based at the headquarters of the Preparatory Commission for the CTBTO in Vienna.
•The IDC supports the verification responsibilities of the States Parties by providing objective products and services necessary for effective global monitoring.
Transmission of data to the IDC
•Over 100 stations are already transmitting data to the IDC, many of them continuously.
•Global coverage is being ensured through the Global Communications Infrastructure (GCI), which receives and distributes data and reporting products relevant to Treaty verification. Data are received and distributed through a network of three satellites.
•The GCI became functional in mid-1999.
•Five GCI hubs have been installed and GCI terminals have so far been set up at 46 IMS stations, national data centres and development sites.
•The GCI hubs are connected via terrestrial links to the IDC in Vienna.
Processing of IMS data at the IDC
•The data, which the IDC uses to detect, locate and analyse events, are processed immediately, with the first automated products being released within two hours.
•The products comprise lists of seismoacoustic events and radionuclides that have been detected by the stations.
•Analysts subsequently review these lists in order to prepare quality-controlled bulletins.
Transmission of data to States Signatories
•The IDC has been providing IMS data and IDC products to States Signatories on a test basis since 21 February 2000.
• Around 50 secure signature accounts have been established, which allow States Signatories to access these data and products.
•IDC software is state-of-the-art, in line with technical and scientific progress.
•Extensive support is given to the users designated by the States Parties by providing a standard software package, training courses and technical assistance( Visit our training and workshops area for more information).
•The IDC operates the computer infrastructure necessary for the Provisional Technical Secretariat (PTS) to execute its mission effectively.
Seismic equipment at one element of an array station, PS02, in Warramunga, Australia
•The seismological monitoring system detects and locates seismic events.
•The CTBT seismic network is composed of 50 primary stations, which send their data in real time to the International Data Centre (IDC) in Vienna, and 120 auxiliary stations that make their data available upon request from the IDC.
•The principal use of the seismic data in the verification system is to locate seismic events and to distinguish between an underground nuclear explosion and the numerous earthquakes that occur around the globe.
There are two different types of seismic stations:
1. Three-component stations have sensors at a single site to measure the three components of the waves (up/down, east/west and north/south) caused by seismic events including earthquakes and explosions.
PS21, a three component seismic station located near Tehran, Islamic Republic of Iran
2. Array stations are sets of 9-25 geometrically arranged seismic sensors distributed over an area of up to 500 km². Seismic array stations have an enhanced detection capacity and independently measure the direction of and distance to the source of an event.
Verification Technologies: Hydroacoustics
Hydroacoustic monitoring detects acoustic waves produced by natural and man-made phenomena in the oceans.
•The CTBT hydroacoustic network comprises eleven stations and cover
s the world's oceans, which make up 70% of the surface area of the earth.
•Few stations are required because of the very efficient propagation of acoustic energy in the oceans.
•The network comprises two different types of stations: "hydrophone" stations and "T-phase" (seismic) stations.
•The CTBT's six hydrophone stations use underwater microphones (hydrophones) that capture signals underwater and then transmit them via cable to the shore station. Hydrophone stations are extremely sensitive and pick up acoustic waves from underwater events, including explosions, occurring very far away.
•Such stations are expensive to install and costly to maintain, so the network also consists of five T-phase (seismic) stations. These stations are located on oceanic islands and use seismometers to detect the acoustic waves that are converted to seismic waves when they hit the island.
•The data from the hydroacoustic stations are used in the verification system to distinguish between underwater explosions and other phenomena, such as sub-sea volcanoes and earthquakes, which also propagate acoustic energy into the oceans.
Verification Technologies: Infrasound
•The CTBT infrasound network of 60 stations uses microbarographs (acoustic pressure sensors) to detect very low-frequency sound waves in the atmosphere produced by natural and man-made events.
•These stations are arrays of 4-8 sensors which are located 1 to 3 km apart.
•The IDC also uses the data to locate and to distinguish between atmospheric explosions and natural phenomena such as meteorites, explosive volcanoes and meteorological events and man-made phenomena such as re-entering space debris, rocket launches and supersonic aircraft.
Verification Technologies: Radionuclide
Radionuclide Station RN23 in the Cook Islands. The air sampler and the satellite communications dish are in the foreground
•The radionuclide network of 80 stations uses air samplers to detect radioactive particles released from atmospheric explosions and vented from underground or under water explosions.
•The relative abundance of different radionuclides in these samples can distinguish between materials produced by a nuclear reactor and a nuclear explosion.
•The associated radionuclide laboratories are used to analyse samples that are suspected of containing radionuclide materials that may have been produced by a nuclear explosion.
•The presence of specific radionuclides provides unambiguous evidence of a nuclear explosion.
•Half of the stations in the radionuclide network also have the capacity to detect noble gases. The presence of noble gases can indicate if an underground explosion has taken place.
Under CTBT, a global system of monitoring stations, using four complementary technologies, is being established to record data necessary to verify compliance with the Treaty.
Supported by 16 radionuclide laboratories, the network of 321 monitoring stations will be capable of registering shock waves emanating from a nuclear explosion underground, in the seas and in the air, as well as detecting radioactive debris released into the atmosphere.
The location of the stations has been carefully chosen for optimal and cost-effective global coverage.
The monitoring stations will transmit, via satellite, the data to the International Data Centre (IDC) within the CTBTO Preparatory Commission in Vienna, where the data will be used to detect, locate and characterize events.
These data and IDC products will be made available to the States Signatories for final analysis
The Reference section provides a gateway to a variety of reference materials on the Comprehensive Nuclear-Test-Ban Treaty Organization.
All published information materials are available as electronic downloads here. Materials in languages other than English are available where possible.
A biannual newsletter on the activities of the CTBTO Preparatory Commission.
Agreements concluded by the Commission
Pursuant to paragraph 7 of the Text on the Establishment of the Preparatory Commission, the Commission has authority to enter into international agreements. The Commission concludes many agreements and arrangements with States and other international organizations. These agreements and arrangements include the following:
IMS Facility Agreements and Arrangements
IMS facility agreements and arrangements regulate the activities of the Preparatory Commission in establishing international monitoring facilities, including the conducting of site surveys, installation or upgrading work, the certification of facilities and provisional operation and maintenance. To date, 32 facility agreements or arrangements have been concluded with States hosting monitoring facilities, of which 24 have entered into force and 2 are being applied provisionally. IMS facility agreements and arrangements that have entered into force are published as documents of the Commission.
The Preparatory Commission became related to the United Nations following the entry into force, on 15 June 2000, of the Agreement to Regulate the Relationship between the United Nations and the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization. The Commission has also concluded agreements with the United Nations Development Programme (UNDP), the World Meteorological Organization (WMO), the Agency for the Prohibition of Nuclear Weapons in Latin America and the Caribbean (OPANAL), the European Centre for Medium-Range Weather Forecast (ECMWF) and the Association of Caribbean States (ACS).
Agreement to Regulate the Relationship between the United Nations and the CTBTO Preparatory Commission
Agreement between the CTBTO Preparatory Commission and UNDP on the Provision of Support Services
Agreement between the CTBTO Preparatory Commission and the WMO
Agreement between the CTBTO Preparatory Commission and OPANAL
Agreement between the CTBTO Preparatory Commission and ECMWF
Agreement between the CTBTO Preparatory Commission and ACS
Host country agreement with Austria
The Agreement between the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization and the Republic of Austria Regarding the Seat of the Commission was concluded on 18 March 1997 and entered into force on 1 November 1997.
Contact CTBTO Preparatory Commission
CTBTO Preparatory Commission
Vienna International Centre
PO Box 1200
A-1400 Vienna, Austria
United Nations, New York, Liaison
Telephone: +43 1 26030 ext. 6200
or any of these extensions 6375/6127/6457/6108/6363
Facsimile: +43 1 26030 5823
Short term contracts
CTBTO Preparatory Commission
Vienna International Centre
Room E0979, PO Box 1200
A-1400 Vienna, Austria
Telephone: +43 1 26030 6210