It is carted from plant to dump by truck secretly so as to avoid publicity - and the possibility of hijack. Plutonium is not a natural element. It is created by human skill and effort - and it is indestructible. The presence of gallium in the plutonium complicates its disposition even further. Originally added to keep the plutonium stable over wide ranges of temperature, gallium generates large amounts of radioactive wastewater if it is removed using current known methods - and it must be removed.
Gallium interferes with the conversion itself and causes chemical problems when the MOx is used.
At the high temperatures required to mix plutonium with glass any gallium present becomes a gas which adheres to the sides of the furnace leaving behind a permanent radioactive metal coating. It is clear that if we do not rid ourselves of the idea that nuclear power is the future we will destroy life and contaminate the planet for millions of years to come. Nuclear waste remains - and may be the greatest environmental problem with which we are faced in the new century.