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Hiroshima for Global Peace

(10) Verifications of Nuclear Weapons Reductions

Russia and the United States have implemented verification measures, including on-site inspections, under the New START. Since its entry into force, they have conducted on-site inspections as stipulated in the treaty.217 However, as mentioned above, due to the pandemic of COVID-19 which made it difficult for inspectors to enter the other countries in 2020, on-site inspections could only be conducted a number of times far below the maximum limit permitted under the treaty.

One noticeable activity on verification is the “International Partnership for Nuclear Disarmament Verification (IPNDV),” launched by the United States in December 2014. With 28 participating countries (and the EU and the Vatican),218 the IPNDV continues to study verification measures and technologies related to the dismantlement of nuclear weapons, as well as fissile material derived from dismantled nuclear warheads.

During Phase III, which began in 2020, partner countries “build on current working methods and engage in further hands-on activities, including scenariobased discussions, practical exercises and technology demonstrations.”219 The following activities were listed:

➢ Use a scenario-based approach based on a full, representative national case study of a notional nuclear weapon possessing state (Country X), and its nuclear enterprise to demonstrate how concepts and other elements of the overall verification “tool kit” developed in Phases I and II can be implemented;
➢ Continue deeper exploration of issues related to the design of verification, such as irreversibility, transparency and the non-production of nuclear weapons, among others, to build confidence over time;
➢ Address gap areas identified through Phases I and II, such as the detection of the presence or absence of nuclearweapon materials, information barrier concepts and technologies; and
➢ Conduct outreach activities to engage senior political leaders, and the nuclear disarmament verification expert community and maintain focus on nuclear disarmament verification.

The first meeting of Phase III was scheduled to be held in Geneva in March 2020, but was cancelled due to COVID-19, and subsequent meetings related to IPNDV have been conducted virtually.

In the meantime, in April, the three working groups of Phase II (Working Group 4: Verification of nuclear weapons declarations, Working Group 5: Verification of reductions, and Working Group 6: Technology for verification) released reports and other materials summarizing the results of their discussions.220

Among them, the Working Group 6 report mentioned technologies and methodologies that do not currently exist and need to be developed: nondestructive detection of explosives in a closed container; quantification of threshold mass of explosives in a closed container; methods for detecting nuclear weapons in a specific location within a large facility or within a building on a site with many buildings while walking or driving near the location; passive measurement of uranium isotopes and threshold mass in a closed container; and sweeping and absence measurements for HEU. It also listed the following technologies and methodologies that currently exist but need additional development or engineering: methods for detecting explosives in rooms from a distance; additional nuclear weapons template methods beyond radiation-based ones; information barrier methods that can be used with a variety of monitoring methods; and evaluation of potential nuclear weapons intrinsic signatures before and after dismantlement.221

At the 2019 NPT PrepCom, Norway proposed to establish a nuclear disarmament verification trust fund under the auspices of UN Office for Disarmament Affairs (UNODA) for increasing capacity building and diversity.222 In addition, the NAM countries called for the establishment by the 2020 NPT RevCon of a standing committee to monitor and verify the nuclear disarmament steps undertaken unilaterally or through bilateral agreements by the NWS.223

217 The U.S. Department of State, “New START Treaty Inspection Activities,”
218 In addition to three NWS (France, the United Kingdom and the United States), Argentina, Australia, Belgium, Brazil, Canada, Chile, Finland, Germany, Hungary, Indonesia, Italy, Japan, Jordan, Kazakhstan, South Korea, Mexico, the Netherlands, Nigeria, Norway, the Philippines, Poland, Sweden, Switzerland, Turkey, the UAE and others participated in the IPNDV. China and Russia attended in Phase I (2015-2017) as observers, but did not join in Phase II (2018-2019).
219 IPNDV, “Phase III Programme of Work,”
220 See the IPNDV web site (
221 IPNDV Working Group 6, “Technology Gaps Identified,” April 2020.
222 “Statement by Norway,” General Debate, 2019 NPT PrepCom, May 1, 2019.
223 NPT/CONF.2020/PC.III/WP.14, March 21, 2019.

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