The history of nuclear energy economics in the UK is complex. The first Magnox reactors were not built for purely commercial purposes, and later reactors faced delays which inflated costs (culminating in Sizewell B taking seven years from start of construction to entering service, after a lengthy public inquiry). Costs have also been complicated by the lack of national strategy or policy for spent nuclear fuel, so that a mixed use of reprocessing and short-term storage have been employed, with little regard for long-term considerations (although a national repository has been proposed).