Despite reservations about unresolved safety issues, the Office for Nuclear Regulation has agreed to accept a safety assessment undertaken by Devonport Royal Dockyard Ltd for the nuclear submarine refuelling facility at HM Naval Base Devonport.
The assessment was undertaken as part of a ten-yearly periodic review of safety at the dockyard’s Low Level Refuelling Facility (LLRF), which is used for the receipt, storage, and dispatch of new and used reactor fuel modules and neutron sources from the refuelling of submarines at the base. This was the first periodic review of safety for the LLRF since it became operational in 2002, since when it has been used during the defuelling and refuelling of Vanguard and Trafalgar Class nuclear powered submarines
Although the periodic review of safety for the LLRF has been approved, ONR consider that “a number of outstanding issues” dating back to 2009 remain unresolved in relation to facility safety. DRDL must “adequately remedy this situation” before the next nuclear use of the facility takes place.
ONR has also expressed concerns about planned dockings in the submarine refit complex at Devonport in the absence of adequate safety documentation. The regulator has advised DRDL that “there is only a short time period and a lack of dedicated resource” available for preparing a safety case necessary for work at 15 Dock at Devonport – one of two dry docks used for maintenance work on Trafalgar class submarines – meaning that the difficulties associated with the next submarine docking in 15 Dock “remain very significant”.
The regulator also warns that “significant capital investment” will be required in future at the ageing submarine refit complex to ensure that it is able to withstand seismic shocks, because “there will … always be uncertainties for a facility built before seismic performance was given the attention that would be required for a new facility”. The submarine refit complex was constructed at Devonport in the 1970s, when nuclear safety standards were less robust than at present and the dockyard was not subject to the external regulation. After a lengthy MoD analysis of the seismic response of the complex, ONR “welcomed the move away from analysis and the commitment to progress physical improvements” at the facility.
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. ONR has given permission for assembly of the building, subject to the implementation of a number of recommendations identified by ONR.
Devonport Royal Dockyard Ltd (DRDL), part of the Babcock International Group plc, is the private sector contractor which undertakes refit and repair work for the Royal Navy’s ships and submarines and provides engineering support and facilities management at HM Naval Base Devonport.
Devonport is the only UK dockyard licensed to do major refits, refuel and decommission nuclear powered submarines. The dockyard currently gets just under half of its revenue from providing support services to submarines.