Principal Mechanical Engineer

Today, Assystem is among the top three independent nuclear engineering firms worldwide. With over 60 years of experience in highly regulated sectors, the group supports public and industrial stakeholders in the execution of complex and strategic infrastructure projects, subject to high safety and security requirements. 

Assystem mobilizes 8,000 experts in 13 countries and intervenes across the entire project lifecycle, in engineering, project management and digital solutions.

Are you an experienced Mechanical Engineer looking to take the lead on exciting, technically challenging projects within a highly regulated industry? We're looking for a motivated and collaborative professional who thrives on solving complex engineering challenges, leading teams, and delivering innovative solutions for our clients.

If you're passionate about engineering excellence and enjoy working in a dynamic, multidisciplinary environment, we'd love to hear from you!

Your missions

As a Senior Mechanical Engineer, you'll provide technical leadership and oversee the successful delivery of engineering solutions that meet customer requirements. You'll work closely with project managers, lead engineers, clients, and multidisciplinary teams to ensure projects are delivered safely, on time, within budget, and to the highest quality standards.

💼 Key Responsibilities

✨ Lead and inspire engineering teams to develop innovative technical solutions.

🤝 Communicate effectively with Lead Engineers and Project Managers, providing regular updates on technical progress and project delivery.

👥 Lead, motivate, mentor and supervise engineers, including supporting the development of junior team members.

🎯 Delegate work effectively while promoting collaboration and teamwork.

⚠️ Identify, review and manage project risks and opportunities proactively.

📋 Oversee the delivery of engineering work packages and ensure technical quality throughout.

📝 Produce and review technical design reports, calculations and engineering documentation to support technical files.

⏱️ Manage your own workload and support the wider team to deliver projects on time, within budget and to agreed quality standards.

📚 Continuously develop your knowledge, seeking guidance where appropriate to support both personal and project objectives.

🔗 Liaise with clients and subject matter experts across engineering, nuclear safety, operations and safety disciplines.

🎓 Qualifications & Experience

✅ Minimum 2:1 BEng in Mechanical Engineering (or equivalent).

🎓 Master's degree is desirable.

🏅 Chartered Engineer status (or working towards Chartership) is advantageous.

🏭 Demonstrable engineering experience within a highly regulated industry.

💻 Experience using 3D CAD software such as Autodesk Revit, Inventor, AutoCAD or CATIA (training can be provided where appropriate).

📊 Experience with FEA and software such as ANSYS, CAESAR II or FlowMaster would be advantageous.

⚙️ Strong understanding of mechanical and structural engineering principles, including pipework and vessel design.

➗ Strong mathematical ability with experience using MathCAD being desirable.

🔄 Thorough understanding of the mechanical engineering design lifecycle, from concept through to manufacture.

🧩 Experience with Requirements-Led Design and/or Model-Based Systems Engineering (MBSE).

📁 Experience producing technical files and LTQR packs.

📜 Good knowledge of relevant engineering legislation, including PED, PUWER and LOLER.

✔️ Experience producing, checking and leading the development of mechanical and structural engineering documentation.

☢️ Experience working alongside Nuclear Safety Engineers to develop safety requirements and engineering safeguards.

⭐ Desirable Skills

🛡️ Understanding of Functional Safety within process and mechanical engineering, including BS EN 61508 and BS EN 61511.

📑 Working knowledge of NEC3/NEC4 contracts with the ability to identify and communicate project risks.

🚰 Strong knowledge of pipework design and associated equipment, including valves, pumps, supports and ancillary systems.

🏗️ Experience engaging with supply chain partners to develop and specify equipment for system delivery.

🔄 Flexible and adaptable, with the ability to support multiple concurrent projects in a fast-paced environment.

Please be aware that this role is subject to both security and export control restrictions.

• These restrictions mean that factors such as your nationality, any nationalities you may have previously held, and your place of birth can restrict the roles you are eligible to perform within the organisation.
• All applicants must as a minimum achieve Baseline Personnel Security Standard. Many roles also require higher levels of National Security Vetting where applicants must typically have 5 to 10 years of continuous residency in the UK depending on the vetting level required for the role, to allow for meaningful security vetting checks.

NOTICE TO CANDIDATES ON RECRUITMENT FRAUD - We are committed to safeguarding candidates from fraudulent activity associated with our recruitment process. Please note that we will never offer specialist CV writing services, request payment or ask for sensitive personal information during the recruitment process.

We are committed to equal treatment of candidates and promote, as well as foster all forms of diversity within our company. We believe that bringing together people with different backgrounds and perspectives is essential for creating innovative and impactful solutions. Skills, talent, and our people’s ability to dare are the only things that matter !. Bring your unique contributions and help us shape the future.