Two British ships have arrived in eastern Japan to transport a shipment of plutonium large enough to make dozens of atomic bombs to the US for storage under a bilateral agreement.
Kyodo News agency said the two ships arrived on the coast of Tokai village, north east of Tokyo and home to the country’s main nuclear research facility, the Japan Atomic Energy Agency.
It will take several hours to load the plutonium on to the ships.
The British-flagged ships operated by Pacific Nuclear Transport will take the 730lb of plutonium to a US government facility in South Carolina.
Japan’s massive stockpile and its fuel-reprocessing ambitions for power generation have been a source of international security concerns.
The ships, Pacific Egret and Pacific Heron, will take the plutonium to the Savannah River Site under a pledge made by Japan in 2014.
Japanese officials refused to confirm details, citing security reasons.
Tokyo has accumulated a massive stockpile of plutonium – 11 metric tons in Japan and another 36 tons that have been reprocessed in Britain and France and are waiting to be returned to Japan – enough to make nearly 6,000 atomic bombs.
The latest shipment comes ahead of a nuclear security summit in Washington, and is seen as a step to showcase both countries’ nuclear non-proliferation efforts.
Washington has increasingly voiced concerns about the spent fuel-reprocessing plans by Japan and China to produce plutonium for energy generation, a technology South Korea also wants to acquire, saying they pose security and proliferation risks.
Japan began building a major reprocessing plant with French state-owned company Areva in the early 1990s. The trouble-plagued project has been delayed ever since, and in November its opening was postponed until 2018 to allow for more safety upgrades and inspections.