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Hiroshima for Global Peace

Hiroshima Report 2018(7) CTBT

A) Signing and ratifying the CTBT

As of December 2017, 166 of the 183 signatories have deposited their instruments of ratification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). No countries newly signed or ratified it in 2017. Among the 44 states listed  in Annex 2 of the CTBT, whose ratification is a prerequisite for the treaty’s entry into force, five states (China, Egypt, Iran, Israel and the United States) have signed but not ratified, ant three (India, North Korea and Pakistan) have not even signed. Among the countries surveyed, Saudi Arabia and Syria, have not signed the CTBT either.

As for efforts to promote CTBT entry into force during 2017, the 10th Conference on Facilitating Entry into Force of the CTBT, or Article XIV Conference, was held on September 20. Participating countries adopted the Final Declaration, in which they, inter alia: conducted by North Korea; urged holdouts to sign and ratify the CTBT without further delay; and called on maintaining the moratorium on nuclear weapons test explosions.145 Prior to this conference, as Co-Coordinators of the Article XIV process on facilitating entry into force of the CTBT, Japanese and Kazakhstani Foreign Ministers, together with the Executive Secretary of the Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO), issued the Joint Appeal for revitalizing efforts for early entry into fore of the treaty.146 In addition, the NPDI proposed at the 2017 NPT PrepCom that “[i]n order to support defusing regional tensions, regionally coordinated ratifications [of the CTBT] could be considered.”147

As for outreach activities for promoting the Treaty’s entry into force, a document, “Activities Undertaken by Signatory and Ratifying States Under Measure (K) of the Final Declaration of the 2015-May 2017,”148 distributed at the Article XIV Conference, summarized activities conducted by ratifying and signatory states. It highlighted:

  • Bilateral activities related to Annex 2 states conducted by Australia, Austria, Belgium, Brazil, Canada, France, Japan, Mexico, New Zealand, Russia, Turkey, UAE, the U.K. and others);
  • Bilateral activities related to non-Annex 2 states (conducted by Australia, Austria, Belgium, Brazil, Canada, France, Japan, Mexico, New Zealand, Russia, Turkey, the U.K. and others);
  • Global-level activities (conducted by Australia, Belgium, Brazil, Canada, France, Japan, Mexico, New Zealand, Russia, Turkey, UAE, the U.K., the U.S. and others); and
  • Regional-level activities (conducted by Australia, Belgium, Brazil, Canada, France, Japan, Mexico, New Zealand, Turkey, UAE and others).
B) Moratoria on nuclear test explosions pending CTBT’s entry into force

The five NWS plus India and Pakistan maintain a moratorium on nuclear test explosions. Israel, which has kept its nuclear policy opaque, has not disclosed the possibility of conducting nuclear tests.

Despite a prohibition of nuclear testing by North Korea under repeated UNSC resolutions, it refuses to declare a moratorium; instead, the North conducted a nuclear test in 2017, as detailed in section E.

C) Cooperation with the CTBTO Preparatory Commission

Regarding the countries surveyed in this study, the status of payments of contributions to the CTBTO, as of 2017, is as follows.149

  • Fully paid: Australia, Austria, Belgium, Canada, Chile, China, Egypt, France, Germany, Indonesia, Israel, Japan, Kazakhstan, South Korea, the Netherlands, New Zealand, Norway, Philippines, Poland, Russia, South Africa, Sweden, Switzerland, Turkey, UAE and the U.K.
  • Partially paid: Mexico and the U.S.
  • Voting right in the Preparatory Commission suspended because arrears are equal to or larger than its contributions due for the last two years: Brazil, Iran and Nigeria

The U.S. National Defense Authorization Act limits funding for the CTBTO, and declares that UN Security Council Resolution 2310 adopted in September 2016 does not “obligate…nor does it impose an obligation on the United States to refrain from actions that would run counter to the object and purpose” of the CTBT. Furthermore, its explanatory statement states that “it is wholly inappropriate for U.S. funds to support activities of the [CTBTO] that include advocating for ratification of the treaty or otherwise preparing for the treaty’s possible entry into force.”150

D) Contribution to the development of the CTBT verification systems

The establishment of the CTBT verification system has steadily progressed. When North Korea conducted a nuclear test in 2017, the International Monitoring System (IMS) detected unusual seismic events.

However, the pace of establishing the International Monitoring System (IMS) stations in China, Egypt and Iran—in addition to those of India, North Korea, Pakistan and Saudi Arabia which have yet to sign the CTBT—has been lagging behind, compared to that in the other signatory countries.151 Regarding China, however, one Radionuclide Station started to operate in December 2016 and another Radionuclide Station was certified in 2017.

In February 2017, Japan announced a voluntary contribution of $2.43 million to the CTBTO “to further boost its verification abilities to detect nuclear explosions anywhere on the planet.” The funding is to be used especially to procure and deploy a mobile noble gas detection system ($1.64 million),152 which will be installed in the northern part of Japan for the first two years.

E) Nuclear testing

After conducting two nuclear tests in 2016, North Korea continued activities which appeared to be in preparation for a further nuclear test.153 Indeed, it conducted its sixth underground nuclear test on September 3, 2017. The IMS of the CTBTO measured 6.0 magnitude. As noted above, the explosive yield of this test far exceeded that of North Korea’s previous nuclear tests.154 On the same day of the test, North Korea announced that it successfully carried out a test of a hydrogen bomb for ICBMs, “the explosive power of which is adjustable from tens kiloton to hundreds kiloton, is a multi-functional thermonuclear nuke with great destructive power which can be detonated even at high altitudes for super-powerful EMP attack according to strategic goals.”155

Although North Korea repeatedly threatened to conduct a nuclear test in the Pacific Ocean, it did not do so in 2017. Meanwhile, it is reported to have continued tunnel work at the West Portal of the Punggye-ri Nuclear Test Site,156 for its future nuclear tests.

Regarding experimental activities other than a nuclear explosion test, the United States continues to conduct various non-explosive tests and experiments under the Stockpile Stewardship Program (SSP), in order to sustain and assess its nuclear weapons stockpile without the use of underground nuclear tests, such as subcritical tests and experiments using the Z machine, which generates X-rays by fast discharge of capacitors, thus allowing for exploring the properties of plutonium materials under extreme pressures and temperatures. The U.S. National Nuclear Security Administration (NNSA), which is part of the U.S. Department of Energy, had released quarterly reports on such experiments, but as of December 2017 has not updated it since the first quarter of FY 2015.

France clarified that it has conducted “activities aimed at guaranteeing the safety and reliability of its nuclear weapons [including] a simulation program and hydrodynamic experiments designed to model materials’ performance under extreme physical conditions and, more broadly, the weapons’ functioning.”157 However, no further detail was reported. Meanwhile, France and the United Kingdom agreed to build and jointly operate radiographic and hydrodynamic testing facilities under the Teutates Treaty concluded in November 2010.158 The status of the remaining nuclear-armed states’ non-explosive testing activities in this respect is not well-known since they do not release any information.

While the CTBT does not prohibit any nuclear test unaccompanied by an explosion, the NAM countries have demanded that nuclear-armed states, inter alia, refrain from conducting nuclear weapon test explosions or any other nuclear explosions, and to close and dismantle, in a transparent, irreversible and verifiable manner, any remaining sites for nuclear test explosions and their associated infrastructure.159

[145] CTBT-Art.XIV/2017/WP.1, September 20, 2017.

[146] “Joint Appeal by Mr. FUMIO KISHIDA, Minister for Foreign Affairs of Japan, Mr. KAIRAT ABDRAKHMANOV, Minister for Foreign Affairs of Kazakhstan and Dr. LASSINA ZERBO, Executive Secretary of the CTBTO PrepCom,” May 2, 2017,

[147] NPT/CONF.2020/PC.I/WP.3, March 17, 2017.

[148] CTBT-Art.XIV/2017/4, September 14, 2017.

[149] CTBTO, “CTBTO Member States’ Payment as at 31-Dec-2017,”

[150] Kingston Reif, “Hill Wants Development of Banned Missile,” Arms Control Today, Vol. 47, No. 10 (December 2017), p. 37.

[151] CTBTO, “Station Profiles,”

[152] “Japan Gives US$ 2.43 Million to Boost Nuclear Test Detection,” CTBTO, February 23, 2017,

[153] For instance, on excavation of underground tunnel at the nuclear test site, see Frank Pabian and David Coblentz, “North Korea’s Punggye-ri Nuclear Test Site: Analysis Reveals Its Potential for Additional Testing with Significantly Higher Yields,” 38 North, March 10, 2017,

[154] A large scale of this nuclear test caused numerous landslides throughout the Punggye-ri nuclear test site and beyond. See Frank V. Pabian, Joseph S. Bermudez Jr., and Jack Liu, “North Korea’s Sixth Nuclear Test: A First Look,” 38 North, September 5, 2017,

[155] “Kim Jong Un Gives Guidance to Nuclear Weaponization,” KCNA, September 3, 2017,

[156] Frank V. Pabian, Joseph S. Bermudez Jr. and Jack Liu, “North Korea’s Punggye-ri Nuclear Test Site: Tunneling atthe West Portal,” 38 North, December 11, 2017,

[157] NPT/CONF.2015/PC.III/14, April 25, 2014.

[158] NPT/CONF.2015/29, April 22, 2015.

[159] NPT/CONF.2015/WP.7, March 9, 2015.

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