Comprehensive Nuclear Test-Ban Treaty (CTBT)

Overview

Potential Facility Impacts

Current Activities

Overview

Purpose and Background

The Comprehensive Nuclear Test-Ban Treaty (CTBT) places a global ban on "any nuclear weapon test explosion or any other nuclear explosion." The Treaty relies primarily on a global information collection and monitoring network to verify compliance, but the Treaty’s verification provisions also include confidence-building measures and the right to conduct on-site inspections when necessary to investigate ambiguous events indicating that a nuclear explosion has occurred.

The CTBT will enter into force 180 days after all of the required 44 states ratify the Treaty. The required 44 states are identified as follows:

• the five acknowledged nuclear-weapon states—United States, Russia, United Kingdom, France and China (all have ratified the CTBT except for China and the United States);
  
  
• India, Pakistan and Israel;
  
  
• members of the Conference on Disarmament (CD) as of June 18, 1996, which also participated in the CD's 1996 session; and
  
  
• states possessing nuclear research or power reactors.

All except three of the required 44 states have signed the CTBT. The three exceptions are India, Pakistan, and North Korea. Thirty-five of the 44 required states have also ratified the Treaty. The United States signed the Treaty on September 24, 1996, but the U.S. Senate declined to ratify the CTBT (48 for, 51 against, 1 abstention) on October 13, 1999.

India and Pakistan each tested nuclear devices in May 1998. On February 21, 1999, the two states signed the Lahore Declaration, pledging their intent to take "immediate steps" to reduce the risk of accidental or unauthorized use of nuclear weapons and discuss further confidence-building measures. In the accompanying Memorandum of Understanding (MOU), both sides committed to continue to abide by their unilateral moratoriums on nuclear test explosions, unless deemed necessary for national security reasons.

The Fifth Conference on Facilitating the Entry into Force of the CTBT was held from September 17-18, 2007. The conference was attended by 106 states, including seven of the states whose ratification of the Treaty is required for the CTBT to enter into force. The United States was not represented at the conference.

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Potential Facility Impacts

Key Verification Measures

To verify compliance, the CTBT relies primarily on the International Monitoring System (IMS) and the International Data Center (IDC). The IDC will be accessible to all States Parties and will receive, collect, process, analyze, report and archive data from the IMS stations.

The IMS is designed to include four global monitoring technologies:

• seismological—50 primary stations and 120 auxiliary stations;



• radionuclide—80 stations monitoring particulates (40 of these stations also monitor noble gases) and 16 radionuclide laboratories;



• infrasound—60 stations monitoring very low atmospheric frequency sound waves potentially caused by a nuclear explosion.

As of July 2009, 247 of the 337 planned IMS stations had been certified and integrated into the IMS, which is 73% of the network. An interactive map showing the location, type, and operational status of each IMS station is provided on the CTBTO Website at: http://www.ctbto.org/map/#ims

The Treaty’s verification regime also includes provisions for on-site inspections, consultations, and clarifications, as well as confidence-building measures. On-site inspections may be conducted to determine whether a suspected nuclear explosion—detected either by the IMS or by the national technical means of a State Party—actually occurred.

Treaty provisions specify a maximum inspection area of 1,000 square kilometers and limit the inspection to 60 days, although a 70-day extension is an option. Inspection activities may include:

• overflight/visual observation, photography, multi-spectral imaging, radioactivity measurement, environmental sampling, and passive seismic monitoring for aftershocks;



• active seismic surveys to locate underground anomalies, plus magnetic and gravitational field mapping, ground-penetrating radar surveys, and electrical conductivity measurements; and



• drilling to obtain radioactive samples.

During an on-site inspection, the inspected State Party will have certain rights to protect sensitive installations and locations. Treaty provisions allow the inspected State Party to designate 4-square kilometer maximum exclusion zones and up to a total of 50-square kilometers of restricted-access sites.

In addition, measures allowed under the CTBT to manage access include:

• shrouding sensitive displays, stores, and equipment;



• restricting measurements of radionuclide activity and nuclear radiation to only enable the inspectors to determine the presence or absence of relevant radiation and energies;



• restricting sampling procedures to only allow inspectors to determine the presence or absence of radioactive or other relevant products;



• managing access to buildings and other structures; and



• declaring restricted-access sites.

When implemented, the CTBT is expected to raise few facility security concerns since most of the Treaty’s compliance verification activities will be conducted remotely and passively through the IMS and IDC. IMF sensors will not jeopardize legitimate sensitive information, although, occasionally a naturally occurring event (e.g., an earthquake) or a non-nuclear activity (e.g., mining) could raise questions that would need to be addressed by other means. Consultations, clarifications, and confidence-building measures will reduce the need for an on-site inspection in such instances but, in exceptional cases, an on-site inspection conducted by a team of international inspectors could be necessary.

In the event of an on-site inspection, potential security concerns would arise. Security risk factors to consider at specific sites and facilities include the length of time an inspection team would be physically present on site and the inspection team’s level of access to specific facilities and programs, the instruments and inspection equipment used, and the types of inspection activities conducted. Under the CTBT, these concerns would be somewhat mitigated by the probability that on-site inspections would most likely occur in remote, non-industrial locations.

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Current Activities

Recent Developments

As of August 2009, 148 States Parties have deposited their instruments of ratification and 181 states have signed the CTBT. Lebanon ratified the treaty on November 25, 2008, and Saint Vincent and the Grenadines became the 181st state to sign the treaty on July 2, 2009.

On September 1, 2008, the CTBTO announced the provisional entry into operation of a joint response system with the World Meteorological Organization (WMO). The WMO will provide high-quality global meteorological data from nine specialized stations to assist the CTBTO in improving Atmospheric Transport Modeling (ATM) calculations. These calculations will enable the CTBTO to more accurately locate a potential nuclear explosion.

The CTBTO conducted its first large-scale integrated CTBT on-site inspection exercise, the Integrated Field Exercise (IFE) 2008. This exercises was conducted from September 1-25, 2008, at the former Soviet nuclear test site in Semipalatinsk, Kazakhstan. IFE 2008 involved 40 inspectors and more than 40 tons of equipment.

In March 2008, the CTBTO launched the International Scientific Studies (ISS) Project. Under this project, more than 60 scientists from 30 countries studied and evaluated the effectiveness of the CTBT’s verification regime. Their findings and recommendations were presented at a global scientific conference held in Vienna from June 10-12, 2009. These findings are summarized below.

• System wide performance: Continuing to increase the sensitivity and technological capabilities of the event-detection equipment used throughout the IMF network is important for ensuring the equipment is able to detect progressively smaller events.



• On-site inspection capabilities: Keeping up-to-date on current inspection techniques and equipment is important, particularly with regard to technological developments affecting mobile equipment, especially portable detectors of the active noble gases xenon and argon.



• Performance of the four IMS networks—seismic, hydroacoustic, infrasound, and radionuclide networks—used to monitor the Earth for any sign of a nuclear explosion:


• Seismic stations: Significant improvements during the past few years have enabled IMS seismic stations to have a very high accuracy rate.



• Hydroacoustic stations: Ten of the projected eleven hydroacoustic stations are certified and this network of hydroacoustic stations has a very high detection capability.



• Infrasound stations: Nearly 70 percent of the projected infrasound stations are certified. Ten additional stations are expected to be certified by 2012. The IMS network of infrasound stations is larger and more sensitive than any other previously operating network. To further improve the monitoring capabilities of these stations will require the development of more reliable atmospheric models.



• Radionuclide stations: Nearly 70 percent of the projected radionuclide stations are certified. All technical specifications have been met and the detection capability of the network meets expectations.

• Atmospheric transport modeling (ATM): The ATM is fully functional. The CTBTO is able to access support from the World Meteorological Organization’s (WMO) Regional Specialized Meteorological Centers on a 24-hour basis.



• Information technologies used to analyze and interpret data (particularly in the IDC, which receives up to 9 GB of monitoring data daily for analysis): Ensuring a balance between detection and screening capabilities is important. Useful technologies may include data mining, historical archives, machine learning, pattern recognition, and fusing data from different sources.

The 32nd session of the CTBTO PrepCom took place from June 8-9, 2009, and the 33rd session is scheduled to meet from November 16-19, 2009. The plenary body will be comprised of two working groups and an advisory group, which will meet throughout the year to discuss administrative and verification issues.

In September 2009, the CTBTO will meet for the Conference on Facilitating the Entry into Force of the CTBT (also called the Article XIV Conference) in New York. Consistent with the Obama administrations’ decision to actively pursue U.S. ratification of the CTBT, the United States will send a high-level representative to the Article XIV Conference for the first time since 1999. The plenary body is comprised of two working groups and an advisory group. These groups will meet throughout the year to discuss administrative and verification issues.