Principal Stress 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.

Assystem’s Fusion and Modular Nuclear team are working on some of the most projects in the UK. Our Simulation and Assessment team of stress engineers support these projects by producing design and regulatory justification assessments of high-integrity and safety critical components to international codes and standard such as RCC-M or ASME III.

We are seeking a Principal Stress Engineer role who will lead the scoping, bidding and delivery of stress engineering work packages, and building and leading a team to deliver this work.

• Lead bids and projects
• Develop future technical leaders
• Plan capability, resourcing and business wining alongside our leadership team

You will lead project teams and technical work in client facing roles, delivering high-quality stress analysis and structural integrity assessments:

• Act as a technical lead for stress and structural integrity, providing expert advice, troubleshooting, and technical oversight.
• Represent Assystem in client meetings.
• Serve as an Independent Technical Approver to ensure the highest engineering standards.
• Use Finite Element Analysis and traditional hand calculations to justify strength, fatigue, defect tolerance, and structural performance to international codes and standards (including pressure vessel and defect-tolerance codes).
• Collaborate closely with safety case authors, design engineers, and multidisciplinary delivery teams.
• Mentor junior engineers, offering technical guidance and helping shape our next generation of stress specialists.

Your role will play an important part in developing and growing Assystem’s internal stress capability:

• Support the strategic development roadmap for the UK stress engineering capability.
• Maintain and improve technical processes, methods, best-practice guides and quality frameworks.
• Monitor workload, skill gaps and training needs across the stress discipline.
• Lead technical upskilling initiatives such as internal training pathways.

• Work with the Engineering Directors and Business Management teams to forecast demand, plan workforce requirements, and shape the long‑term capability pipeline.
• Support recruitment campaigns, interviewing and selecting high-quality candidates.
• Ensure strong retention by fostering a supportive culture, mentoring talent, and providing growth opportunities.

• Collaborate with Sales and Business Development teams to identify opportunities where stress capability adds value.
• Lead bids, proposals, client presentations and technical sales materials.
• Represent stress capability in major pursuits and innovation initiatives.

• Act as a visible leader and ambassador for stress engineering across Assystem and with clients.
• Build and maintain relationships with key technical stakeholders, partners and industry bodies.

• Over 55 years in nuclear engineering.
• Ranked among the top 3 largest nuclear engineering companies.
• Attractive social benefits, including an engaging…