The water removes leftover heat generated by the spent fuel and serves as a radiation shield to protect workers at the site. The operation of nuclear reactors over the last twenty years has substantially added to the amount of radioactive waste in this country. As shown in Figure 1, by the year 2020, the total amount of spent fuel is expected to increase significantly. HLW is the liquid waste that results when spent fuel is reprocessed to recover unfissioned uranium and plutonium. Plans are to solidify these liquids into a form that is suitable for disposal.
Solidification is still in the planning stages.
While currently there are no commercial facilities in this country that reprocess spent fuel, spent fuel from defense program reactors has been routinely reprocessed for use in producing nuclear weapons or for reuse in new fuel. Compared to the total inventory of HLW, the volume of commercial HLW from the reprocessing of commercial spent fuel is almost insignificant, less than one percent. Figure 2 shows the historical and projected volume of defense-related HLW through the year 2020. These facilities have begun programs to solidify and structurally stabilize the waste in preparation for disposal at a national repository. Regulation of Disposal Some elements, such as plutonium, in HLW and spent fuel are highly radioactive and remain so for thousands of years.