Nuclear mattersWeapon-grade fissile material in the world could yield 126,500 nuclear bombs

Published 15 April 2010

The nations of the world together have in their possession about 1.6 million kilograms of highly enriched uranium (HEU) and about 500,000 kilograms of plutonium; it takes only about 25 kilograms of HEU or eight kilograms of plutonium to make a crude nuclear bomb; thus the weapon-grade material now available in the world could yield 64,000 HEU-based bombs and 62,500 plutonium-based bombs

The nuclear summit President Barack Obama convened in Washington, D.C. earlier this week focused less on nuclear weapons and more on more poorly guarded nuclear materials that could be used to build nuclear weapons or dirty bombs. The reason for this focus: Obtaining enough plutonium or highly enriched uranium is the most important step toward getting a nuclear weapon.

Robert Gallucci, a former U.S. ambassador-at-large for nonproliferation issues, says it is possible that al Qaeda or some other terrorist group could steal or buy ready-made nukes. The world’s warheads, however, are relatively secure and accounted for. The stockpiles of fissile materials sprinkled around the globe are another matter. “I think the chances of Al Qaeda acquiring fissile material and making its own improvised nuclear device are greater than the chances it will get an already-fabricated weapon and detonate that,” said Galluci, now president of the MacArthur Foundation, in a Monday speech.

Agreements to tighten controls

Christian Science Monitor’s Peter Grier writes that Obama’s summit already has produced some agreements intended to help corral the world’s loose nukes problem. On Monday, Ukraine, Canada, and Malaysia all agreed either to reduce or tighten controls on their stores of highly enriched uranium. On Tuesday, Mexico made a similar commitment.


How much loose nuke material is out there? A lot, writes Grier. The nations of the world together have about 1.6 million kilograms of highly enriched uranium (HEU) and about 500,000 kilograms of plutonium, according to data compiled by Harvard’s Belfer Center for Science and International Security.

Simple division shows the magnitude of the threat this bomb-ready material portends. It takes only about 25 kilograms of HEU or eight kilograms of plutonium to make a crude nuclear bomb.

Fissile material is held at hundreds of locations, with varying levels of security. There are more than 130 research reactors alone that are powered by HEU, some of them in developing or transitional countries, notes the Belfer Center (see William J. Broad, “Research Reactors a Safety Challenge,” 12 April 2010 New York Times).

Vietnam, for instance, has at least 5 kilograms of HEU, according to a list compiled by the Institute for Science and International Security (ISIS). Jamaica has a kilogram. So does Ghana.

Worldwide, many of these locations need better security. Would it be difficult for terrorists to break in and get their hands on fissile material? Not difficult enough. “The threat looms large,” according to Matthew Bunn, a principal investigator at the Belfer Center.

Bunn says that he greatest threat is in Pakistan, which has almost one ton of plutonium plus a smaller amount of HEU. Pakistan’s stockpile is well-guarded, but it confronts “immense threats from both insider theft and outsider attack,” Bunn says.

Terrorist groups known to be seeking fissile material

Grier writes that in the past, al Qaeda has tried to buy nuclear material on the world black market. So has the Japanese group Aum Shinrikyo, which gained notoriety via its 1995 sarin gas attack on the Tokyo subway. Other terrorist groups that have shown interest in acquiring a nuclear capability include the South Asian Islamists of Lashkar-e-Taiba and Chechen separatists.


A series of events in recent years has raised the world’s awareness of the loose nukes problem, according to Tanya Ogilvie-White, a senior lecturer at the University of Canterbury in New Zealand and co-author of a U.S. Council on Foreign Relations report on nuclear security. In 2007, for instance, a group of eight people broke into South Africa’s Pelindaba nuclear reactor and research center (see Ben Frankel, “More Questions than Answers in South Africa’s Nuclear Facility Attack,” 15 November 2007 HSNW; and “IAEA Finds South Africa’s Nuclear Facility Safe,” 29 January 2008 HSNW).

“They actually got into it, and there was enough nuclear material stored there for about 25 nuclear weapons. Luckily, it was stopped by security services,” said Ogilvie-White in remarks posted on the Council on Foreign Relations Web site. Ogilvie-White says she is optimistic that the world will move toward taking better care of its loose nuclear material, now that countries have awakened to the extent of the danger.