The Royal Navy operates a total of seven nuclear powered attack submarines (SSNs) in two classes – the Trafalgar Class and the Astute Class. They are capable of continuous patrols at high underwater speed, independent of base support, can circumnavigate the globe without surfacing and are capable of firing Tomahawk cruise missiles. These are in addition to the four Vanguard class nuclear powered ballistic missile submarines (SSBN) each of which are armed with Trident II missiles that make up the UK’s nuclear deterrent force.
Her Majesty’s Naval Base (HMNB) Devonport located west of Plymouth in Devon, is the largest naval base in Western Europe and the sole nuclear repair and refueling facility for Royal Navy SSN and SSBM submarines. The co-located Royal Dockyard Lt (DRDL) is part of the Babcock International Group plc, and the only UK dockyard licensed to do major refits, refuel and decommission nuclear powered submarines. As part of a £5 billion contract to refit the Vanguard class vessels, they are berthed in a specially-converted dock because they are too big for the yard’s other docks at 150m (492ft) long.
Babcock is the sole provider of deep maintenance, in-service maintenance and infrastructure support for the UK fleet of conventional and nuclear powered submarines. Its teams have been instrumental in bringing the Royal Navy’s new Astute Class into service, alongside its role as long-term provider of submarine operator and maintainer training.
In mid-2012 HMS Vigilant rejoined her two older sisters Vanguard and Victorious in the deterrent cycle after completing a £333 million upgrade of her systems when her nuclear reactors were refueled and new reactor cores fitted. In all some 2.3 million man-hours (more than 37½ years) were spent revamping Vigilant before she sailed from Devonport to begin her regeneration.
In March 2012 the MoD awarded Babcock a £350 million contract to refit and refuel HMS Vengeance, the newest of the four Trident-carrying strategic missile submarines. Work on the 15,000-tonne vessel will include a complete overhaul of equipment, improved missile launch capabilities and upgraded computer systems. A new reactor core will also be fitted that will last the submarine until she is decommissioned. The old reactor core and spent fuel rods, all of which are highly radioactive, will be transported to be stored at Sellafield.
Rolls Royce in Derby design and produce the reactors and reactor cores for these and Britain’s other nuclear powered submarines. During refit, the radioactive coolant water from the submarine’s reactor is allowed to be discharged into the local river, the River Tamar. In the past, Devonport has also been the site of several accidental leaks of nuclear waste from RN submarines.
In addition to the recent SSBN refits, refueling will be conducted within the currently planned dry dock maintenance period for HMS Vanguard, which starts in late 2015 and will take more than three years to complete, although the MoD does not expect this to have any impact on deterrent operations. This will be the second time Vanguard’s reactor has been refueled since it entered service in 1993.
Work is currently underway at Devonport on construction of a new Reactor Access House for 14 Dock, which will be used for defuelling laid up submarines currently in the dockyard. The Office of Nuclear Regulation (ONR) has given permission for assembly of the building, subject to the implementation of a number of recommendations.
Five nuclear facilities across the UK have been identified as potential sites to store waste from nuclear-powered submarines that have left Royal Navy service, as part of the MoD’s Submarine Dismantling Project (SDP).
The sites, which do not include Devonport, are either owned by the MoD, the Nuclear Decommissioning Authority (NDA) or industry, and already hold radioactive materials and have been identified as possible locations to store reactor components from the disused submarines.
The MoD has a total of 18 former Royal Navy nuclear submarines currently stored afloat in Devonport and Rosyth, which can only be completely dismantled once the reactor components, which are categorised as radioactive waste, have been safely removed.
The five Trafalgar class and four Vanguard class in-service submarines will also be dismantled under the SDP when they reach the end of their service lives. Following an assessment of all the UK’s nuclear sites, five sites were considered suitable and have been placed on a provisional shortlist.
The potential sites are the Atomic Weapons Establishment sites at Aldermaston and Burghfield in Berkshire, which are owned by the MoD and run by AWE Plc; Sellafield in West Cumbria and Chapelcross in Dumfriesshire, both owned by the NDA, and Capenhurst in Cheshire, which is run by Capenhurst Nuclear Services.
A public consultation on the possible sites will take place in late 2014 and no decisions will be made until this process is completed. Whichever site is selected will be used as an interim storage site for the reactor components until after 2040, when the UK’s Geological Disposal Facility is planned to come into operation.