Two British ships arrive in Japan to transport plutonium for storage in U.S.

AP

Two British ships arrived in eastern Japan on Monday to transport a shipment of plutonium — enough to make dozens of atomic bombs — to the U.S. for storage under a bilateral agreement.

The ships docked at the coastal village of Tokai, Ibaraki Prefecture, which is home to the nation’s main nuclear research facility, the Japan Atomic and Energy Agency, according to Kyodo News and citizens’ groups. Loading the plutonium-filled casks onto the ships, both fitted with naval guns and other protective devices, was expected to take several hours.

The Pacific Egret and Pacific Heron, both operated by Pacific Nuclear Transport Ltd., will take the 331 kg (730 pounds) of plutonium to the Savannah River Site, a U.S. government facility in South Carolina, under a pledge made by Japan in 2014. The plutonium, mostly from the U.S. and some from France originally, had been used for research purposes.

Japanese officials refused to confirm details, citing security reasons.

Japan’s stockpile and its fuel-reprocessing ambitions to use plutonium as fuel for power generation have been a source of international security concerns.

Japan has accumulated a massive stockpile of plutonium — 11 tons in the country and another 36 tons that have been reprocessed in Britain and France and are waiting to be returned — enough to make nearly 6,000 atomic bombs.

The latest shipment comes just ahead of a nuclear security summit in Washington later this month, and is seen as a step to showcase both countries’ nuclear nonproliferation efforts.

Washington has increasingly voiced concerns about the nuclear 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.

Experts say launching the Rokkasho reprocessing plant in Aomori Prefecture will not ease the situation, because Japan has little hope of achieving a spent-fuel recycling program.

Japan’s Monju plutonium-burning fast breeder reactor, suspended for more than 20 years, is now on the verge of being closed due to poor safety records and technical problems, while optional plans to burn uranium-plutonium mixtures of MOX fuel in conventional reactors have been delayed since the Fukushima disaster.

Only two of the country’s 43 workable reactors are currently online.