Mixed Oxide Plutonium Fuel (MOX) is composed of uranium dioxide and plutonium dioxide powders which are mixed inside of fuel pellets. Because plutonium releases more radioactivity than uranium, this mixed fuel is more difficult to control inside of reactors and requires more safeguards than traditional uranium reactor fuel. In 2008 MOX fuel rods being tested by Duke Energy started warping and Duke withdrew from the Nuclear Regulatory Commission’s testing agreement.
The additional risks posed by MOX plutonium fuel, along with renewed global skepticism about nuclear power in the wake of the Fukushima disaster, have resulted in the world-wide decline of the MOX industry. Japan has cancelled all of its orders for MOX plutonium fuel and the UK has recently closed its MOX plant in Sellafield due to a lack of customers. With no willing customers, the Department of Energy is pressuring the Tennessee Valley Authority (TVA) to use MOX plutonium fuel. Some of the reactors that TVA is considering for MOX have the same Mark I exploding design that failed in Fukushima.
The US MOX program results from the 1998
Agreement on the Management and Disposition of Plutonium with Russia. This agreement designates 54 metric tons of surplus weapons grade plutonium for “immobilization” through irradiation as MOX fuel. Most of this plutonium comes from dismantled warheads. Although MOX is funded as a
nonproliferation program, it actually increases proliferation risks in two ways:
- By transporting dangerous plutonium oxide powder from Los Alamos National Laboratory in New Mexico where the US is currently processing its weapons plutonium to the Savannah River Site in South Carolina where MOX fuel assemblies will be manufactured.
- Encouraging commercial markets for plutonium as reactor fuel.
Today, the Russians have changed their minds about what they will do with their MOX fuel and plan to use it in “breeder reactors” which actually generate more plutonium – hardly a nonproliferation advance. Adding salt to this wounded program is its cost; ballooning from an original estimate of $1.6 billion to $9.7 billion today.