Principal Mechanical Engineer

Role OverviewA Principal Mechanical Engineer is required to provide senior technical leadership across nuclear new build, defence, and decommissioning programmes. The role focusses on delivering high-integrity mechanical engineering solutions within a highly regulated environment, ensuring all work meets stringent nuclear safety, security, and quality requirements.Key Responsibilities

• Lead the design and analysis of mechanical systems and components, including pressure systems, HVAC, lifting equipment, pipework, and safety-classified mechanical assemblies.
• Act as Technical Authority for mechanical engineering, providing oversight, verification, and approval of design outputs.
• Ensure compliance with nuclear safety principles, site licence conditions, and UK regulatory frameworks.
• Lead the development, justification, and substantiation of safety-classified mechanical systems, producing evidence to support safety case requirements.
• Conduct and review HAZOP, FMEA, reliability assessments, and stress/thermal analyses.
• Manage project delivery across multidisciplinary teams, ensuring outputs meet quality, cost, and schedule commitments.
• Support bids and proposals through technical scoping, risk identification, and resource planning.
• Engage with clients, regulators, and stakeholders, providing clear technical leadership during design reviews and technical meetings.
• Promote innovation in nuclear mechanical systems, including digital engineering, resilience, and low-carbon technologies.

Required Experience

• Extensive experience in nuclear mechanical engineering within consultancy, defence, or major infrastructure environments.
• Strong understanding of safety-classified equipment, substantiation, and nuclear safety case requirements.
• Proven ability to lead engineering teams delivering complex mechanical design packages.
• Experience with pressure systems, rotating machinery, HVAC, pipework design, and mechanical handling equipment.
• Familiarity with UK nuclear regulatory bodies and standards, including ONR guidance, Pressure Systems Safety Regulations (PSSR), and relevant BS/EN/ASME codes.

Preferred Qualifications

• Chartered Engineer (CEng) or working toward chartership.
• Degree in Mechanical Engineering or a related discipline.
• Experience with digital engineering tools, modelling platforms, and nuclear-specific analysis software.

SummaryThis role is suited to a senior mechanical engineer with deep nuclear sector experience who can lead complex design work, provide technical authority, and ensure compliance with the highest safety and regulatory standards.

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