The UK’s new military naval reactor dismantling facility, situated inside HMNB Devonport, is set to begin operations at some point this year, in a significant development of the country’s plan to scrap dozens of decommissioned nuclear-powered submarines that were once in service with the Royal Navy.

Located on 14 Dock, part of UK defence prime Babcock’s own Royal Dockyard – a private industrial enclave inside HMNB Devonport – the new reactor dismantling facility will begin work soon, according to Babcock officials, followed several years of development.

The site is a key part of the Submarine Dismantling Project, which is managed by the Submarine Delivery Agency (SDA) and responsible for the disposal of 27 nuclear submarines; 22 of which are decommissioned and have left service, while five currently continue to be operated by the Royal Navy.

Following two public consultations, the UK Ministry of Defence selected a three-stage approach to dismantling, having also engaged with Nato partners, likely to gather information on processes and recycling practices.

In Nato, the US and France are the only two other operators of nuclear-powered submarines, although countries such as Italy, Sweden, Germany, and Norway, among others, utilise conventionally powered diesel-electric submarines.

In total, seven of the submarines intended to be recycled in Rosyth, with the remaining 20 in Devonport.

UK spends £500m storing decommissioned nuclear submarines

Following a hiatus from the early-2000s, the UK will once again be able to dispose of the remaining reactors still inside decommissioned nuclear submarines, that have been powered down but still require constant observation and cooling to ensure they remain in a safe state.

Babcock expects that one decommissioned nuclear submarine will be able to be dismantled per year, although once nuclear contaminated material had been removed at the 14 Dock facility, the remaining hull or casing of the submarine could be scrapped outside of the Royal Dockyard.

In 2023 the UK’s planned dismantling of decommissioned nuclear-powered submarines in service got underway as the former HMS Swiftsure was dry-docked at Babcock’s shipyard in Rosyth, Scotland, to begin preparations for final disposal.

According to the UK’s SDA, detailing the development in a post on social media, HMS Swiftsure was to be the first nuclear powered submarine to be fully dismantled at the end of 2026, and done so in a way that has “not been attempted by any other nation”.

Around 90% of components, including steel, can be reused for recycling in the process, which will all be undertaken at the Rosyth site. Commissioned into service in 1972, HMS Swiftsure was the lead boat in the Swiftsure-class nuclear-powered submarines (SSN) and operated until its decommissioning in 1992.

The outcome of the work being undertaken to dismantle HMS Swiftsure will in turn provide a better understanding in how to expand the process to HMNB Devonport. According to a 2019 investigation by the UK’s National Audit Office into submarine defuelling and dismantling, the MoD had spent an estimated £500m ($629m) since 1980 on storing and maintaining its retired nuclear submarines.

The UK currently has five of the latest Astute-class SSNs in service or commissioned (Astute, Ambush, Artful, Audacious, and Anson), along with a single remaining Trafalgar-class SSN, HMS Triumph. A further two boats are under construction (Agamemnon and Agincourt), with each boat costing between £1.3-1.6bn and expected to serve for at least 25 years with the Royal Navy.

In addition, the RN operates four Vanguard-class SSBNs (Vanguard, Victorious, Vigilant, Vengeance), which will be replaced by the incoming Dreadnought-class submarines, with the first-in-class currently in manufacture at the BAE Systems yard in Barrow-in-Furness, UK.

The UK has also begun the process to replace the Astute class with the planned AUKUS SSN being developed for use by the Royal Navy and Australia. The class is effectively an evolution of the UK’s SSNR (Submersible Ship Nuclear Replacement) concept originally intended as the Astute-class replacement.

The AUKUS SSN is likely to feature the under-development Pressurised Water Reactor 3 (PWR3) that will be installed on the Dreadnought-class SSBNs and feature a vertical launch system from which to fire surface and land attack munitions.