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Hiroshima for Global Peace

(11) Irreversibility

(11) Irreversibility

A) Implementing or planning dismantlement of nuclear warheads and their delivery vehicles

As with their previous nuclear arms control agreements, the New START obliges Russia and the United States to dismantle or convert strategic (nuclear) delivery vehicles beyond the limits set in the Treaty, in a verifiable way. The New START does not stipulate that retired nuclear warheads be dismantled, but the two states have partially dismantled retired nuclear warheads as unilateral measures. As mentioned above, the Department of Defense decided not to disclose the information regarding the number of dismantling nuclear weapons. France and the United Kingdom also continue to dismantle their retired nuclear warheads and delivery vehicles.

B) Decommissioning/conversion of nuclear weapons-related facilities

No remarkable activity or progress was reported in 2019 in terms of decommissioning or conversion of nuclear weapons-related facilities.220

In 1996, France became the only country to decide to completely and irreversibly dismantle its nuclear test sites. They were fully decommissioned in 1998.221 As mentioned above, North Korea declared to close its nuclear test site, but whether the “shutdown” is complete and irreversible has yet to be confirmed.

C) Measures for fissile material declared excess for military purposes, such as disposition or conversion to peaceful purposes

In October 2016, Russian President Putin issued a Presidential Decree on suspending implementation of the Russian-U.S. Plutonium Management and Disposition Agreement (PMDA), which entered into force in July 2011. Russia argued that it suspended the PMDA in response to U.S. “hostile actions toward Russia” and a “radical change of circumstances” since the agreement was signed in 2000.222 In 2019, its mixed oxide (MOX) fabrication plant used reactor-grade plutonium while, according to the original plan, the plant was to process weapon-grade plutonium that Russia committed to eliminate under the PMDA.223

In the meantime, the Trump administration, like its predecessor, has sought to end construction of the MOX fuel fabrication Facility (MFFF) at the Savannah River Site in South Carolina, and to pursue the dilution and disposal approach, due to increasing cost and delaying schedule of the MFFF’s construction. The Congress has not approved this approach, and allocated a budget for the construction of the MFFF.224 However, the NNSA formally terminated its construction in October 2018.225 The NNSA is proposing to repurpose the Mixed Oxide Fuel Fabrication Facility (MFFF) to produce plutonium pits.

U.S. nuclear warheads have been dismantled at the Pantex facility in Texas, and there are 54 tons of surplus plutonium stored in Department of Energy facilities around the United States, an amount that is increasing.226 As for surplus highly enriched uranium (HEU), according to the Department of Energy budget request, the United States will complete 162 tons of dilution in fiscal 2019 (159.7 tons have already been diluted).227

220 See also the Hiroshima Report 2017.

221 NPT/CONF.2015/10, March 12, 2015.

222 Maggie Tennis, “INF Dispute Adds to U.S.-Russia Tensions,” Arms Control Today, Vol. 47, No. 5 (June 2017), pp. 29-30. The report by the U.S. Department of State in April 2019 stated: “There is no indication that Russia has violated any of its obligations under the PMDA. Russia’s October 2016 notification of its purported suspension of the PMDA raised concerns regarding Russia’s future compliance with its PMDA obligations.” The U.S. Department of State, “Adherence to and Compliance with Arms Control, Nonproliferation, and Disarmament Agreements and Commitments,” August 2019, p. 22.

223 “Russia Uses Civilian Reactor-Grade Plutonium to Produce MOX Fuel for BN-800,” IPFM Blog, August 29, 2019,

224 Kingston Reif, “MOX Facility to Switch to Plutonium Pits,” Arms Control Today, Vol. 48, No. 5 (June 2018), p. 29.

225 Timothy Gardner, “Trump Administration Kills Contract for Plutonium-to-Fuel Plant,” Reuters, October 13, 2018, for-plutonium-to-fuel-plant-idUSKCN1MM2N0.

226 Scot J. Paltrow, “America’s Nuclear Headache: Old Plutonium with Nowhere to Go,” Reuters, April 20, 2018,

227 “United States to Down-Blend HEU for Tritium Production,” IPFM Blog, October 1, 2018,

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