What is Plutonium Management and Disposition Agreement (PMDA)?

Why in News ? The Russian Duma has formally ratified a departure from the Plutonium Management and Disposition Agreement (PMDA) with the United States, which is a major nuclear agreement between the U.S. and Russia. Although Russia suspended its activity under the PMDA in 2016, today represents the official and formal end to the PMDA.

The abandonment of the PMDA comes amid heightened tensions on the part of Russia with the West, specifically NATO expansion, sanctions, and the deterioration of U.S.-Russia relations. Russia claims all of these actions have eroded the trust that is required for the PMDA to be effective.

What is the PMDA?

• The PMDA is a bilateral agreement between the United States and Russia which was originally signed in 2000, and amended in 2010 — which began to be enacted in 2011.
• The PMDA required each country to dispose of 34 metric tons of weapons-grade plutonium — enough for thousands of nuclear weapons.
• The idea was to render the plutonium incapable of being repurposed for weapons, either through the production of mixed oxide nuclear reactor fuel (MOX) or through other disposal methods.

Why did Russia withdraw?

• Russia criticized the U.S. for changing its disposal method from turning plutonium into MOX fuel to instead diluting and burying it, which Russia said could be reversible.

• Russia also cited political reasons, such as U.S. sanctions, military buildup near its borders, and what it sees as a hostile stance by the West.

• It argues that the original conditions of trust and cooperation no longer exist.

 Why does this matter?

• The PMDA was one of the few remaining arms control agreements between the two biggest nuclear powers.

• Its collapse marks a major setback for global nuclear nonproliferation and reduces transparency in how nuclear materials are handled.

• It also highlights the broader breakdown of arms control treaties — following other withdrawals like from the INF Treaty and the Open Skies Treaty in recent years.

What is MOX fuel?

• MOX (Mixed Oxide) fuel is a kind of nuclear fuel that is a combination of:
• Plutonium dioxide (PuO₂) — typically from dismantled nuclear weapons or reprocessed waste from reactors
• Uranium dioxide (UO₂) — generally a low enriched or natural uranium
• So rather than simply filling a reactor with uranium (as is done with conventional nuclear fuel), it uses plutonium to generate usable reactor fuel.

Why is MOX fuel utilized?
Recycling weapons plutonium!

• It allows for the safe disposal of weapons-grade plutonium, by converting it to fuel to produce electricity.
• Once plutonium is consumed in a reactor, it is much more difficult (and less desirable) to put it back in a nuclear weapon.

Energy value:

• MOX can substitute 5% to 10% of the fuel of some reactors without require any significant adjustments.
• In reactors specifically designed or modified for MOX, more fuel can be replaced with MOX.

How is MOX fuel fabricated?

• Plutonium is purified from dismantled weapons or spent fuel.
• It is mixed with uranium dioxide powder.
• The mixture is pressed into pellets, then sintered (heated in a furnace), and finally the pellets are put into fuel rods.