Enforcement action over crane safety at Devonport nuclear dock

Aerial photo of HMNB Devonport showing 5 basin and the low level refuelling facility. Image credit: MoD/Wikipedia

In 2017 the Office for Nuclear Regulation (ONR) served Devonport Royal Dockyard Limited (DRDL) with two improvement notices after a series of safety incidents at the nuclear dock where HMS Vanguard is being refuelled. The improvement action came as inspections by regulators uncovered numerous shortcomings at the site, which is already subject to enhanced regulation.

DRDL is used to do deep maintenance, refitting and refuelling of nuclear submarines. HMS Vanguard is currently being refitted with an unscheduled refuelling, after a fuel element breach was discovered in the Vulcan Nuclear Reactor Test Establishment at Dounreay.

The crane safety incidents occurred during a five week period between May and June 2017 at the 9 Dock facility. Fortunately nobody was injured during the incidents and there was no loss of control of radioactive material, but ONR said that lifting operations and crane maintenance fell short of the required standard. The improvement notices relate to regulations on crane operations and nuclear licensee conditions that deal with “examination, inspection, maintenance and testing.”

The exact nature of the incidents themselves has not been released, but DRDL enacted a safety stand-down of all crane operations at 9 Dock. After ONR had conducted return to service inspections crane operations were allowed to resume with temporary safety arrangements. The improvement notices required changes to be made by 1st December 2017, but an extension until 22nd December was requested by DRDL and granted by ONR. On 21st December ONR announced that DRDL had complied with the terms of the improvement notices.

The improvement notices come in a year when numerous problems at DRDL have been highlighted by regulators. The site has been subject to enhanced regulatory attention since 2013 and has had to put in place a Nuclear Safety Improvement Plan. However ONR have said the progress is slower than expected and DRDL need to work harder on delivery and implementation.

In 2017 inspectors also highlighted the fact that fire detection, alarm and emergency systems in the Submarine Refuelling Centre, which will be used to defuel old nuclear submarines in the Submarine Dismantling Project, are “ageing and require extensive ongoing maintenance”. They also found inconsistent implementation of operating instructions in the Reactor Access House (RAH) lifts that will be used to remove reactor components from HMS Vanguard, and said that DRDL need to implement a coherent plan for fulfilling current and future radioactive waste requirements. An inspection in June found that fire safety improvements requested in a letter sent in February had not been progressed. Inspectors also identified issues with training, safety mechanism documentation, and documentation of maintenance work.

9 Dock was built between 1896 and 1907 to service the Dreadnought warships of that era. It was adapted to service nuclear submarines in the 1990s at the same time that the current Vanguard submarines were being brought into service. The cranes at the centre of the improvement notices likely date back to this time. Removal of the nuclear reactor itself is done using the lifts in the RAH so it is unclear whether the cranes are ever used to move nuclear materials. However, ONR found it necessary to point out that none of the crane incidents involved the loss of control of radioactive material.