Actemium Design UK – celebrating 40 years of nuclear engineering excellence and trusted delivery
From the decommissioning of Sellafield's most challenging legacy facilities to supporting the UK's latest nuclear defence programmes, Actemium Design UK marks 40 years of specialist nuclear engineering that helps clients manage risk, navigate complex regulatory requirements and deliver critical infrastructure with confidence.
Founded on 14 January 1987 as North West Projects Limited, the business began life as a specialist Control, Electrical and Instrumentation (CE&I) design consultancy serving the UK’s civil nuclear industry. Four decades later, it has evolved into Actemium Design UK, combining established nuclear expertise and customer relationships with the wider capabilities and resources of the Actemium and VINCI Energies network, to support programmes of national significance across the nuclear and nuclear defence sectors.
Building a record of trusted engineering delivery at Sellafield
Actemium Design UK’s history is closely linked to that of Sellafield, one of the world’s most complex nuclear decommissioning programmes. For many years, the company’s engineers, designers and project managers have contributed to major projects involving some of the site’s most hazardous legacy facilities, including the Magnox Swarf Storage Silo (MSSS), Pile Fuel Cladding Silo (PFCS) and First Generation Magnox Storage Pond (FGMSP).
As Sellafield’s decommissioning mission grew and matured, so too did the business’s contribution to the safe retrieval, processing and storage of nuclear waste. This included projects such as the Silo Maintenance Facility (SMF), Encapsulated Product Store 3 (EPS3) and Box Encapsulation Plant (BEP).
Over the decades, North West Projects, and subsequently Actemium Design UK, has also supported Sellafield’s programmes through a succession of commercial frameworks, including the Design Services Alliance (DSA), Infrastructure Strategic Alliance (ISA), Decommissioning Delivery Partnership (DDP) and Project and Programme Partners (PPP).
This long-standing involvement has built deep site knowledge and experience of these nuclear facilities, helping delivery partners manage engineering complexity, maintain compliance and build confidence in project outcomes.
From specialist CE&I design to multidisciplinary engineering
Alongside its growing role at Sellafield and an expanding client base across the nuclear sector, North West Projects progressively broadened its engineering capabilities to meet the evolving needs of nuclear operators and delivery partners.
Building on its CE&I heritage, today the business provides mechanical and process engineering, engineering assurance and substantiation, stress analysis, project management services, and more.
This multidisciplinary expertise enables clients to access support across the engineering lifecycle – from feasibility studies and optioneering through to detailed design, implementation, commissioning, plant life extension and asset care. Bringing these disciplines together helps improve design coordination, manage technical interfaces and reduce risk across complex nuclear programmes.
Engineering methods have also evolved alongside the business’s capabilities, with laser scanning, 3D printing, virtual reality and rapid prototyping complementing established design and analysis techniques. Together, these tools help Actemium’s teams assess existing site conditions, validate proposed solutions and identify potential installation constraints earlier, supporting more informed decisions and more efficient project execution.
Extending proven nuclear expertise into defence
In recent years, Actemium Design UK has furthermore extended the application of its civil nuclear expertise to programmes supporting the UK’s nuclear defence sector.
While civil nuclear and nuclear defence operate within distinct regulatory and operational environments, both demand rigorous engineering assurance, robust information management and strict control of technical and safety-related requirements.
Today, Actemium Design UK applies its engineering, project management and technical assurance capabilities to programmes supporting the UK’s next-generation submarine capability and the infrastructure associated with the Continuous At Sea Deterrent (CASD).
Experience gained from legacy nuclear facilities, complex engineering modifications and safety-critical infrastructure provides a strong foundation for supporting defence programmes, where engineering integrity, configuration control and long-term reliability are essential to successful project delivery.
40 years of trust, built through delivery
Since its establishment, Actemium Design UK’s journey has included several important milestones, including a management buyout in 2005, joining VINCI Energies in 2017 and adopting the Actemium name in 2021.
And while the business has transformed and grown over time, the engineering expertise, nuclear sector knowledge and commitment to trusted delivery that have shaped its success continue to underpin every project.
Today, it combines this heritage with access to broader engineering capabilities, specialist resources and international expertise through the Actemium and VINCI Energies network. For clients, this provides the reassurance of an experienced nuclear engineering partner backed by the strength and scale of a global organisation.
As Actemium Design UK enters its fifth decade, it remains focused on helping delivery partners reduce risk, maintain compliance, improve project performance and prepare critical nuclear infrastructure for the future, guided by the same principles that have underpinned the business since 1987: engineering excellence, technical integrity and trusted delivery.
