The Nuclear Security Summit Communiqué Statement on Separated Plutonium Is a Step Backward

March 25, 2014 | 3:14 pm
Ed Lyman
Director, Nuclear Power Safety

The communiqués issued at the previous two Nuclear Security Summits said almost nothing about the dangers of separated plutonium. That was a problem. The 2014 Nuclear Security Summit communiqué does say something about plutonium—but the world would have been better off if it had remained silent on the issue.

The communiqué statement, although vague, promulgates the false and very dangerous notion that MOX fuel, a mixture of plutonium and uranium, is much less of a security threat than pure plutonium:

“Furthermore, a considerable amount of HEU has been down-blended to low-enriched uranium (LEU) and separated plutonium converted to mixed oxide (MOX) fuel. We encourage States to minimize their stocks of HEU and to keep their stockpile of separated plutonium to the minimum level, both as consistent with national requirements.”

The problem is that, contrary to the impression this statement gives, converting plutonium into MOX would offer little barrier to theft and subsequent use in producing nuclear weapons.  One MOX fuel assembly contains many bombs’ worth of plutonium, and can be rapidly disassembled, if necessary, to facilitate theft.

The Summit statement implies that converting separated plutonium to MOX fuel has a comparable security benefit to down-blending highly enriched uranium (HEU) to low-enriched uranium. Nothing could be further from the truth. To reverse HEU downblending would require access to uranium enrichment technology—something that is generally out of reach for sub-national groups. To reverse blending of plutonium with uranium would only require a modest capability for chemical processing that could be accomplished in a small-scale and easily concealable glovebox facility.

One of the chief beneficiaries of the communiqué statement is Japan. Japan is facing increased criticism from its neighbors, like China, for its plans to increase its already substantial stockpile of separated plutonium by starting up the Rokkasho reprocessing plant.  This plan is especially problematic given the collapse of Japan’s strategy for using plutonium as MOX fuel in its currently shuttered fleet of nuclear power plants. Since Japan is building a MOX fuel fabrication plant adjacent to Rokkasho, the communiqué statement gives Japan cover for separating additional plutonium provided that it fabricates it into MOX fuel, even if the fuel is stored for decades before it is irradiated in nuclear reactors.

UCS has been working to try to prevent an effort by the U.S. Nuclear Regulatory Commission to downgrade the security requirements for MOX fuel and other forms of plutonium diluted with other materials. The communiqué statement will set back that and other efforts to ensure adequate controls over all materials that are useful to terrorists seeking nuclear weapons.