2.1 Decommissioning and cleaning up Sellafield will involve completing current commercial operations and decommissioning and demolishing the buildings on site. The highest hazard facilities on the site are the four legacy ponds and silos. The Nuclear Decommissioning Authority's (the Authority's) strategy prioritises making clear progress on these programmes. In this part we address progress at site level, on the legacy ponds and silos programmes, and on the largest projects on the site, many of which are within the legacy ponds and silos programmes.