Blog Post - Nuclear Security Matters

Japanese Nuclear Material Arrives in the United States

| Aug. 25, 2016

This week the National Nuclear Security Administration (NNSA) announced that 546 kilograms of plutonium and highly enriched uranium (HEU) shipped from Japan arrived in the United States.

The 331 kilograms of plutonium and 214.5 kilograms of weapons-grade HEU stored at the Fast Critical Assembly at Tokai-mura was one of the most attractive targets in the world for would-be nuclear thieves. The removal of this nuclear weapons-useable material was an important achievement in reducing the risk of nuclear terrorism (although Japan still possesses 10.8 tons of separated plutonium and 1.8 tons of HEU).

The U.S.-Japanese agreement to ship the material to the United States was first announced at the 2014 Nuclear Security Summit in The Hague. Two years later, in the days leading up to the 2016 Nuclear Security Summit in Washington, D.C., the material was loaded onto the Pacific Egret and Pacific Heron, transport ships bound for the United States.

This effort was not without controversy. The HEU was sent to the Y-12 facility in Oak Ridge, Tennessee, while the plutonium was sent to the Savannah River Site in South Carolina. South Carolina Governor Nikki Haley has repeatedly protested the shipment of nuclear material to her state. In a recent statement, she said, “South Carolina will not be a permanent dumping ground for nuclear waste.” That is currently not the plan. Over the next few years, NNSA intends to dilute the plutonium for eventual long-term storage at the Waste Isolation Pilot Plant in New Mexico, although some question whether this is feasible.

For more information on this publication: Belfer Communications Office
For Academic Citation: Roth, Nickolas.Japanese Nuclear Material Arrives in the United States.” Nuclear Security Matters, August 25, 2016,

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