The Plutonium Management and Disposition Agreement is an agreement between the United States and Russia signed in 2000, wherein both nations agreed to dispose of significant fractions of their "excess" (beyond what they need for their nuclear weapons) weapons-grade plutonium. An amended version was signed in April 2010 and went into effect in July 2011. The US has about 90 tons of weapons-capable plutonium, while Russia has 128 tons. The US declared 60 tons as excess, while Russia declared 50 tons excess. The two sides agreed that each would eliminate 34 tons. The agreement regulates the conversion of non-essential plutonium into mixed oxide (MOX) fuel used to produce electricity. Both sides were required to render 34 tons of weapons grade plutonium, into reactor grade plutonium alongside reaching the spent fuel standard, that is mixed with the other more highly irradiating products within spent fuel. In 2007, the US began constructing the Mixed Oxide Fuel Fabrication Facility (MFFF) on the Savannah River Site. For financial reasons, US president Barack Obama canceled construction of the MFFF in 2016 and proposed that the plutonium be diluted with non-radioactive material and disposed in the underground WIPP facility. However, the dilution could be reversed, and the material reconverted into weapons-grade plutonium. By 2015, Russia was on track and had begun producing MOX fuel at its own MOX facility, for its fast reactor, the BN-800. On October 3, 2016, Russian president Vladimir Putin ordered the agreement to be suspended because the US did not meet their obligations. External links Agreement text: English – Agreement between the Government of the United States of America and the Government of the Russian Federation Concerning the Management and Disposition of Plutonium Designated as No Longer Required for Defense Purposes and Related Cooperation Russian – Соглашение между Правительством Российской Федерации и Правительством Соединенных Штатов Америки об утилизации плутония, заявленного как плутоний, не являющийся более необходимым для целей обороны, обращению с ним и сотрудничеству в этой области Plutonium Disposition Program, National Nuclear Security Administration, 26 June 2013. Anatoli Diakov: Disposition of Excess Russian Weapon HEU and Plutonium, Center for Arms Control, Energy and Environmental Studies, February 2012. References Treaties entered into force in 2000 Treaties of Russia Treaties of the United States Arms control treaties Nuclear weapons policy