Cover Image


View/Hide Left Panel

al-Qa’ida, have voiced this desire, though it is not clear how determined they have been at acquiring the capability. The trends are not encouraging, however: terrorists appear to be seeking ever-increasing levels of destruction in order to increase the impact of each new attack. In addition, increasing ties have been observed between these groups and elements in states that might be able to help the terrorists achieve their goals. Even without state assistance, U.S. nuclear weapons experts agree that some terrorist groups would be technically capable of constructing a primitive nuclear device, if they were able to obtain the necessary fissile materials. Former director of Los Alamos National Laboratory, Siegfried Hecker, has noted that some Russian weapons experts agree that from a technical point of view the construction of the simplest type of first-generation nuclear device is within the capabilities of certain non-state actors.198

In examining the steps for terrorist acquisition of such a device, experts from the U.S. Department of Energy (DOE) have noted that the key difficulty facing such an endeavor is obtaining “access to special nuclear material” – highly enriched uranium (HEU) or plutonium.199 The Department of Homeland Security (DHS) has stated that its experts do not believe that terrorists can enrich uranium or breed plutonium. Therefore, DHS avers that the only way a terrorist could access this material is by theft from a fuel cycle facility, purchase on the black market, or transfer from a state sponsor.200 An additional possible pathway to obtain HEU suggested by a Russian study is the re-enrichment of low-enriched uranium. While this runs contrary to the U.S. view that terrorists do not have access to enrichment technology, re-enrichment might be a risk if non-state actors receive assistance from someone with access to a state program. The Kurchatov Institute study of the risks of the proliferation of various nuclear materials concluded that the risks posed by low-enriched uranium (LEU) exceeded those of HEU by a factor of 39.201 While the underlying assumptions behind this estimate are not made public, it appears that they were assuming that those stealing the nuclear materials had access to enrichment capabilities. It is probable that the study was focusing on proliferation to state actors, not terrorists. While even states have had difficulty creating enrichment capabilities, they clearly have a better chance of doing so than non-state actors at present.

A gun-type device is easier to construct than a nuclear implosive device.202 Since a gun-type bomb that employed HEU would have a yield of 10-15 kilotons, while a similar plutonium-based gun-type device would result in a “fizzle yield” of 10-20 tons, preventing terrorist


Siegfried Hecker, comment made during his presentation of “Toward a comprehensive safeguards system: Keeping fissile materials out of the terrorists’ hands.” Pir Center Conference on G8 Global Security Agenda: Challenges and Interests Toward the St. Petersburg Summit, Moscow, April 22, 2006.


See K. Todd Wilber (National Nuclear Security Administration Office of Emergency Response), “Overview of Radiological/Nuclear Devices and Response,” available at; accessed May 1, 2008.


“Nuclear Smuggling,” Department of Homeland Security Nuclear Assessment Program, available at; accessed May 1, 2008.


See Nikolai Ponomarev-Stepnoi, “Stsenarii razvitiia atomnoi energetiki Rossii v XXI veke” (Scenarios for the Development of Atomic Energy in Russia in the 21st Century), Biulleten’ po atomnoi energii, December 2001, p. 7.


This view is widely held by U.S. experts. Sergey Pertsev, Head of the 12th Central Scientific Research Institute of the Russian Defense Ministry has agreed with this view; conversation with author, October 4, 2007, Moscow. It should be noted that a crude gun-type device would not likely result in an efficient use of the nuclear material, but would create a nuclear yield.

The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement