After the fuel had been in the reactor for about four years, it became depleted and was sent to the spent fuel pool to cool for about year before it was shipped to New York for reprocessing. But fuel reprocessing ended in 1977 when President Carter forbade the transport of spent fuel due to environmental and security concerns. Until then, Big Rock Point's used fuel went out by rail in 70-ton steel casks 17 feet long and 5 feet wide, capable of holding 18 bundles.