At the end of last week, Japan Nuclear Fuels Limited (JNFL) announced that it will begin separating plutonium from spent reactor fuel at its new Rokkasho reprocessing plant. Japan will begin "active testing" of the plant in the next few days with actual spent fuel, becoming the first non-nuclear weapons state to operate a plutonium separation facility on an industrial scale. If successful, the test will separate about four metric tons of plutonium over a seventeen-month period; at peak capacity, the plant will be able to separate about eight metric tons annually. Japan currently has a stockpile of more than 40 metric tons of separated plutonium.

The Union of Concerned Scientists (UCS) has warned that the operation of this plant will further erode the nuclear non-proliferation regime and will ultimately increase the risk that terrorists will obtain the materials needed to make nuclear weapons. UCS has criticized the Bush administration for not taking action to stop the Japanese program and has warned that the new U.S. Global Nuclear Energy Partnership (GNEP) will encourage the spread of reprocessing and dangerous stockpiles of weapons-usable plutonium.