The first process step used in nuclear fuel reprocessing. It involves all the process stages of mechanical sectioning of fuel elements in preparation for chemical extraction. This includes feeding the fuel elements into a sectioning machine that cuts the fuel element bundles into roughly 5cm-long pieces. The rod pieces then fall into concentrated nitric acid to dissolve the uranium, plutonium, and fission products. The cladding material of the fuel rods is resistant to the acid. Compare tail end.