Nuclear Threats

Recognizing the Nuclear Threat

Detecting Nuclear thrests

“The single biggest threat to U.S. security…would be the possibility of a terrorist organization obtaining a nuclear weapon.”

President Obama, April 2010


“The threat of nuclear terrorism is real, and the global nuclear security system needs to be strengthened in order to counter that threat.”

IAEA Director General Yukiya Amano

The new nuclear threat is terrorism

The modern nuclear threat is no longer missiles launched from cold war enemies. The new threat is terrorism: a non-state actor that accumulates enough nuclear material to build an improvised nuclear device (IND). Even a crude device—made with small amounts of plutonium in an inefficient design—could obliterate a city block, cause tens of thousands of casualties, crash economic markets, and re-shape the global security landscape.



“Well over a hundred incidents of thefts and other unauthorized activities involving nuclear and radioactive material are reported to the IAEA every year. Some material goes missing and is never found.”

 International Atomic Energy Agency (IAEA) Director General Yukiya Amano

  • 9

    Countries with nuclear weapons

  • 8kg

    Plutonium (Pu) —about the size of a grapefruit—needed for a crude nuclear bomb

  • 20kg

    Highly Enriched Uranium —about the size of a 5 lb. bag of sugar—that could make a crude nuclear bomb

  • 25

    Countries with more than 1 kg weapons-usable nuclear material

  • 2000

    Sites around the world where PU and HEU are stored


  • Dirty Bomb

    Dirty Bomb

    A dirty bomb, formally known as a “radiological dispersion device,” is a conventional explosive packed with radioactive material. While often mentioned side-by-side with nuclear bombs, a dirty bomb is actually much less harmful—its destructive power is no greater than an ordinary bomb, and it is unlikely to cause significant radiation contamination. Such a device would cause more economic and psychological damage than physical damage.

  • nuclear-threat

    Nuclear Bomb

    A nuclear bomb harnesses the explosive energy that comes from splitting the atom. A small nuclear device could vaporize a city block and inflict casualties and damage orders of magnitude greater than a regular bomb. Of all the materials that emit harmful radiation, only two can be used to build a nuclear bomb: plutonium, and highly enriched uranium.


Learn More:  Dirty Bomb v. Nuclear Bomb


The best way to stop nuclear terrorism is to secure all nuclear weapons material at their storage sites.




  1. Before
  2. After


About 3,000 radiation detectors are deployed to scan traffic at U.S. border crossings and some key international borders and high-volume shipping ports. This is far from enough: tens of thousands more detectors are needed—to secure weapons-grade nuclear material at storage sites, to monitor international transit routes, and to detect nuclear devices that are smuggled into cities.

Networks of radiation sensors are the key to increased detection. When detectors are linked up and share information, the strength of detection is more than the sum of each individual sensor. Connected radiation sensors are the future of nuclear threat reduction.

Low-cost, large-area radiation detectors are the key to making these networks economically feasible.