
A surplus of Japanese plutonium over the next few years could pose significant nuclear dangers for the region and the world unless it is addressed now, a new report released this week by a Washington, D.C.-based think tank has warned.

Japan is the only non-nuclear-weapon state which extracts plutonium from the spent fuel produced in nuclear reactors – a process called reprocessing – to fabricate more fuel, a controversial practice since the plutonium can also be used to make nuclear weapons. While Tokyo has pledged not to produce more plutonium than it consumes, the fallout from the 2011 Fukushima incident makes it likely that Japan will violate that commitment in the next decade, with a plutonium conversion facility still in the works and only a portion of its reactors that consume plutonium likely to be restarted before the reprocessing plant is at full capacity.

Japan’s resulting plutonium glut, argues James Acton, a longtime nonproliferation analyst, must be averted by Tokyo and its partners because it would set a damaging precedent, exacerbate regional tensions and increase the likelihood of nuclear terrorism.

“It would…be shortsighted to conclude that [Japan’s] existing plutonium stockpile, let alone the possibility that it may grow rapidly, does not pose serious security risks,” Acton, now a senior associate at the Carnegie Endowment for International Peace, writes in the report.

To address this, the report argues that the central government – instead of the private sector – should publicly assume responsibility for the plutonium balance given the serious security implications, and that Tokyo should seriously explore the feasibility of shifting to the once-through fuel cycle. Abroad, it urges Japan to collaborate with the United States and other European states managing plutonium, including concluding a side agreement with Washington as part of an extension of their existing nuclear cooperation pact.

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“Given these risks, Japan has a clear interest in ensuring that it lives up to its commitments by not accumulating even more plutonium and, ideally, drawing down its existing stockpile over time,” the report argues.

The report’s recommendations, Acton told The Diplomat in an interview Tuesday, amount to a solution rooted in “realism” that takes into account both Japan’s domestic politics and international obligations. The report does acknowledge, for instance, that local politics “entraps” the Japanese government into supporting reprocessing and makes a complete reversal unlikely. At the same time, it also recognizes that the only way the central Japanese government can adhere to its commitments and avert the risks of a serious plutonium glut is to act decisively now on its own and in concert with partners.

“What unites these recommendations is the need for the central government to take action,” Acton writes in the report.


The report also underscores the urgency of the task at hand. While the coming plutonium glut may be a decade away according to Acton’s projection, he argues that sticking to the current path will only make it more difficult for Tokyo to convince local stakeholders about the need for policy change further down the line and waste the critical time needed to develop a credible plan to manage plutonium.

“Unfortunately, waiting will probably make the problem even more vexing,” Acton warns.

The obstacles to implementing some of these proposals are clear. Efforts to escape the ‘entrapment’ of reprocessing will likely encounter familiar resistance from certain interest groups. Individual proposals, as the report itself acknowledges, may also be difficult to implement such that the government may decide that the costs of reprocessing outweigh the benefits. Even more reason then, perhaps, for Japan as well as its partners like the United States to start seriously thinking about this problem now to navigate past these challenges before the clock begins to run out.