The primary goal of this work was to evaluate the efficacy of the chop-leach spent fuel dissolution process, with nitric acid dissolvent, for removing actinides and fission products from Zircaloy cladding to produce a cladding capable of meeting low-level waste (LLW) disposal criteria. Analysis of the cladding shows that actinides are present in the cladding at concentrations 50 to 400 times greater than the acceptable TRU limit in LLW. It appears that the nitric acid used for dissolution (initial concentration 4 M, with 10 M added as the dissolution proceeded) was inadequate for solubilizing the fuel meat. Scanning electron micrographs of the as-sampled cladding surface showed particles of material high in U on the surface of the cut samples, suggesting the fuel meat was not completely dissolved. If the cladding is to meet LLW disposal limits, it is likely that a more robust chemical treatment will be required to more completely digest the fuel meat. Based on the available analytical results, and the interpretation of those results, the following conclusions are drawn. The chop-leach method, as performed initially was inadequate for complete digestion of the fuel meat present in the Dresden-1 fuel samples studied. This failure of the dissolution process resulted in cladding samples that contained TRU actinides about 400 times more TRU content than is allowable in LLW. The inductively-coupled plasma emission spectroscopy (ICP-ES) method appears to overestimate the quantities of a variety of elements, such as Ag, Ce, Gd, La, and Sb. It is believed this phenomenon is related to spectral interferences from d-block and f-block elements. Future studies should be performed to determine the efficacy of leaching to chemically polish the cladding surface and remove undissolved fuel meat. Further analyses of cladding samples, to more thoroughly characterize the nature of the U- and TRU-bearing phases present in the cladding, are recommended.
