Welcome to DML Group

FACILITY DESIGN AND SAFETY

DML's Facilities Engineering Group provides professional support to plant managers, nuclear and non-nuclear operations managers and acts as DML's Design Authority. The function has responsibility for the maintenance of the design intent and certification of "fitness for purpose" for the entire infrastructure, operations and facilities throughout their life. The Group has responsibility for progressing new designs and modifications and for endorsing Certificates of Design as facilities are handed over from construction projects to operational control. The resources for this function are provided by professional, specialist designers and safety case engineers.

The function also supports the through-life management of all assets, the production of design substantiation reports and provision of examination, inspection, maintenance and testing procedures.

Safety Case Production

DML is required to have written documentation, (known as safety cases), to demonstrate that the safety of its nuclear operations is "tolerable" and the risks arising are "As Low As Reasonably Practicable" (ALARP). The documentation includes a description of the plant and the operations that will be carried out together with analysis that shows how the proposals meet the high standards that are an essential ingredient of all nuclear activities and operations. Safety cases that are categorised as having the highest level of safety significance are submitted to the regulators (Nuclear Installations Inspectorate and Ministry of Defence) for their assessment and agreement.

During 2005, several safety cases were submitted for NII and MoD regulatory agreement. Acceptance by the regulators of these safety cases has allowed submarine refitting operations to continue. In particular, these included safety cases to allow the refit of HMS Victorious in 9 Dock. In addition, safety case updates, to account for lessons learnt during the first refit of a Vanguard Class submarine, were produced and submitted to the regulators in preparation for the arrival of the second boat in the Class - HMS Victorious.
Other safety case submissions allowed the continuation of HMS Talent's refit in 14 Dock, including the removal of used fuel and its replacement with new fuel as well as preparations for HMS Triumph's refit in 14 Dock . In addition, submarine maintenance dockings have continued in 10 Dock.

Safety cases are regularly reviewed throughout their life to check that claimed standards remain up-to-date and to account for operational experience. DML's Nuclear Site Licence requires a formal periodic review of safety cases, but the company also initiates reviews whenever operations covered by a case are improved or changed.

DML continues to build on the good progress made over the last year to develop the quality of its safety arguments and engineering. A nuclear facility operator must not allow safety case standards to fall behind national and international good practice. DML reviews the quality of its safety cases and the associated analyses continuously to ensure that any risks arising from operations on the site remain "As Low As Reasonably Practicable" (ALARP).

Staff Training and Development

In 2005, DML continued to recruit and develop its professional graduate group of engineering expertise. This initiative has been recognised by both regulators and UK professional institutions as comparable with national best practice. These young safety engineers will form the backbone of DML's professional specialist expertise in the future, which is essential to ensure that the company's nuclear safety standards are maintained and developed.

Independent Peer Review

The role of the Independent Peer Review Department is to assess the adequacy of safety cases to ensure compliance with relevant Licence and Authorisation Conditions. Reviews are required to confirm that documents are of the right standard and content before they are submitted for final Safety Committee consideration prior to submission to the regulators.

This team is independent from those groups responsible for the production of safety cases and is composed of individuals who have many years' experience of interfacing with safety cases and NII Site Licence/MoD Authorisation requirements.

The IPR Manager, who reports to the Director of Nuclear, Safety & Quality, has a team of two full-time assessors augmented by external consultants as necessary.

As safety case programmes progress, IPR's critical, but constructive, approach is intended to pre-empt queries from the Safety Committee and regulatory assessment process. It also stimulates improvement in the presentation of complex arguments and ensures consistency and best practice across a broad range of submissions.

In 2005, the team was involved in the justification for completion of the HMS Vanguard activities in 5 Basin including Power Range Testing and the commencement of HMS Victorious' refit, including Primary Circuit Decontamination in 9 Dock. The team also reviewed safety cases for other activities in the Submarine Refit Complex (SRC), 10 Dock and afloat in 5 Basin.