IS DILUTION THE SOLUTION TO THE PLUTONIUM THREAT?

President Obama said at the April 2010 Nuclear Security Summit that the possibility of nuclear material falling into the hands of terrorists is the \"number one security threat\" in the world, and he has subsequently continued his push to \"secure\" all vulnerable materials within four years. But his words seem to have fallen on deaf ears back home at the Nuclear Regulatory Commission (NRC), which is poised to significantly reduce security requirements for civil special nuclear materials when being transported or stored in certain forms. Specifically, the NRC is considering downgrading the security classification for mixed-oxide (MOX) fuel. MOX fuel assemblies containing 2 or more kilograms of plutonium are considered to be Category I items under current rules, and hence require the highest level of physical protection when transported or stored away from reactors. (The security requirements for MOX fuel at power reactors have already been downgraded under a 2009 rule change.) However, the Department of Energy and the Tennessee Valley Authority have pressed the NRC to downgrade the security classification of MOX fuel when being transported so that it can be shipped in ordinary trucks instead of safe secure trailers (SSTs). The rationale is presumably that MOX fuel is not an attractive material for diversion or theft provided the plutonium is diluted below a certain threshold. In 2009, the NRC staff sent the Commission a paper on this issue, \"Material Categorization and Future Fuel Cycle Facility Security-Related Rulemaking\" (SECY-09-0123). The Commission's response and the votes of two Commissioners were made public, although the paper itself is not. The Commission authorized the staff to develop a material categorization approach that would address, among other things, MOX fuel for the purposes of transportation. In other areas of material protection, control and accounting (MPC&A), the NRC is also authorizing significant deviations from current rules and practices, most notably with regard to the program at the MOX fuel fabrication facility at the Savannah River Site. This paper will examine the domestic and international implications of weakening MPC&A standards for plutonium at a time when the threat of nuclear terrorism is increasing.