Spent fuel was previously used in a reactor to produce electricity, Sellafield received this material for reprocessing from four European countries between 2002 and 2005. A spokesperson for Sellafield Limited said: "The four European countries Sellafield received spent fuel from in this period are Germany, Switzerland, the Netherlands and Italy." Residue produced in reprocessing is returned to overseas customers that sent it as spent fuel. Sellafield's response under environmental information regulations confirmed that the site did not receive spent fuel from European countries between 2018 and 2009. More information about the spent fuel reprocessing process can be found here: https://ukinventory.nda.gov.uk/wp-content/uploads/2014/01/Fact-sheet-spent-fuel-reprocessing.pdf