The International Panel on Fissile Materials (IPFM) has published Global Fissile Material Report 2011: Nuclear Weapon and Fissile Material Stockpiles and Production (pdf file).

The report provides updated estimates for global and national stockpiles of highly enriched uranium (HEU) and plutonium, the key ingredients in nuclear weapons and recent developments in military and civilian fissile material production capabilities in nuclear weapon states and in the non-weapon states. Accurate information on highly enriched uranium and plutonium production and stocks is necessary to support progress on nuclear disarmament and nonproliferation.

In 2011, the global stockpile of nuclear weapons is estimated at over 19,000 weapons, including operational warheads and warheads awaiting dismantlement, with the United States and Russia together holding over 18,000 of these weapons. All the weapon states are modernizing their arsenals and in some cases building new weapon production infrastructure.

The global stockpile of HEU is about 1440 +/- 125 tons, enough for more than 60,000 simple, first generation implosion fission weapons. About 98 % of this material is held by the nuclear weapon states, with the largest HEU stockpiles being held by Russia and the United States. The global HEU stockpile is shrinking as Russia and the United States each blend down HEU that they have declared to be excess to their military needs. India and Pakistan continue to produce HEU. No other state is believed to be producing HEU.

The non-nuclear weapon states have about 10 tons of HEU, almost all of which was provided to them as research reactor fuel by the weapon states.

The number and capacity of civilian uranium enrichment plants worldwide continues to grow, with the largest expansion of civilian uranium enrichment capacity occurring in the United States.

The global stockpile of separated plutonium in 2011 is estimated at about 495 +/- 10 tons. About half of this stockpile was produced for weapons, while the other half has mostly been produced as part of civilian reprocessing programs in nuclear weapon states. As a result, about 98 per cent of all separated plutonium is in the nuclear weapon states today. Russia, the United States, and the United Kingdom have not begun to dispose of the military plutonium stocks that they have declared excess. France and China have not declared any plutonium as excess to military purposes.

The stockpile of separated plutonium for weapons continues to increase because of production in India, Pakistan, and perhaps Israel. The United Kingdom, France, and Russia and Japan have accumulated the largest civilian plutonium stockpiles. The civilian plutonium stockpile will increase much faster if India and China go forward with their reprocessing programs. There are about 10 tons of plutonium in Japan, the only non-weapon state with a significant program to separate plutonium from spent nuclear fuel today. Japan also owns about 35 tons of plutonium in France and the UK.

This is the sixth Global Fissile Material Report by the International Panel on Fissile Materials.