Analysis & Opinions - Nuclear Security Matters

Eliminating Potential Bomb Material from Japan’s Fast Critical Assembly

| March 24, 2014

"Today, the United States and Japan announced that Japan would eliminate all the plutonium and highly-enriched uranium at its Fast Critical Assembly (FCA) at Tokai-mura.  This is a tremendous step forward for nuclear security; for terrorists, this would be some of the best material that exists in any non-nuclear-weapon state.  The material includes 331 kilograms of plutonium, most of it weapons-grade, and 214.5 kilograms of weapons-grade HEU.  (The FCA also includes over a ton of material just at the 20 percent U-235 mark that defines HEU.)   The weapons-grade HEU is enough for four simple terrorist “gun-type” bombs or a larger number of trickier-to-build implosion bombs.  The plutonium amounts to more than 40 bombs worth of material..."


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For Academic Citation: Bunn, Matthew.“Eliminating Potential Bomb Material from Japan’s Fast Critical Assembly.” Nuclear Security Matters, March 24, 2014.

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