Principal Mechanical Engineer

Job Description

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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