Technical Subject Matter Expert (SME)

Amentum is the Design & Engineering partner within the Programme and Project Partners (PPP) framework at Sellafield — a 20-year strategic alliance delivering £7bn of major infrastructure projects. We are seeking a Technical Subject Matter Expert (SME) to provide deep domain expertise and technical leadership across complex engineering programmes. What You’ll Be Doing: * Act as the technical authority in your discipline, providing expert guidance across design, delivery, and assurance phases. * Support project teams with specialist knowledge to resolve complex engineering challenges. * Lead and contribute to technical reviews, design assurance activities, and risk assessments. * Ensure compliance with regulatory standards, safety requirements, and industry best practices. * Collaborate with internal and external stakeholders to ensure technical integration and alignment. * Mentor engineers and contribute to the development of technical capability across the organisation. * Influence strategy and decision-making through technical insight and evidence-based recommendations. What We’re Looking For: * Recognised technical expert in a relevant engineering discipline, Chartered with a relevant institution. * Extensive experience in regulated environments (e.g. nuclear, defence, infrastructure). * Proven ability to lead technical assurance and solve complex engineering problems. * Strong communication and stakeholder engagement skills. * Experience supporting large-scale project delivery and multidisciplinary teams