While the US Navy cuts the reactor block out of its old nuclear submarines and buries it whole in a desert trench, Britain has cut 2,695 tons off a 272-foot Cold War attack submarine in a Scottish dry

Key Points:

• The UK Ministry of Defence (MOD) has begun fully dismantling its first retired nuclear submarine, the Swiftsure, marking a shift from decades of leaving decommissioned vessels largely intact, unlike the US method of removing and burying reactor compartments as sealed blocks.
• Swiftsure, retired in 1992 after 19 years of service, has had over 62% of its material removed by June 2025, including the sail, with the next major task being the extraction of the radioactive reactor pressure vessel, which remains highly radioactive despite fuel removal in 1992.
• The extracted reactor vessel will be stored temporarily at Capenhurst until the UK opens a permanent underground disposal facility, expected not before the 2040s, highlighting the long-term challenges of nuclear waste management.
• The MOD aims to recycle 90% of the submarine’s weight through existing UK disposal routes, with some recovered high-grade steel already repurposed for new Royal Navy submarines, demonstrating a sustainable approach to decommissioning.
• Behind Swiftsure, 22 other retired UK nuclear submarines await dismantling, with many still containing nuclear fuel due to halted defueling operations since 2004; recent contracts are aiming to restart and accelerate this process amid costly ongoing maintenance.