Senior/Principal Plant Layout Engineer
Confirmed on the employer's own hiring board on Oct 15, 2026. First seen by Alion on Oct 6, 2026. Assystem scores B on the Alion truth index.
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.
Join the Fusion and Modular Nuclear Business Unit! Reporting to the Layout Engineering Manager, the Principal Layout Integration Engineer will provide technical leadership across Fusion and Modular Nuclear programmes.
The Principal Layout Integration Engineer will act as a recognised subject matter expert for plant layout integration, piping layout, building integration, modularisation and multidisciplinary coordination. The role will support project delivery, capability growth, business development and development of engineering best practice.
Whilst providing technical leadership and strategic direction, the Principal Layout Integration Engineer will remain actively involved in project delivery, supporting development of complex layouts, technical studies and resolution of challenging engineering issues.
Key Responsibilities
- Lead plant layout development from concept through detailed design for complex facilities and plant areas.
- Act as technical lead for major buildings, systems or programme-level integration activities.
- Lead development of equipment, piping, cable tray, access and maintenance arrangements.
- Lead piping routing studies and layout optimisation activities.
- Provide technical leadership across multiple projects and programmes.
- Lead requirements-driven layout development and multidisciplinary integration activities.
- Define layout integration methodologies, standards and engineering approaches.
- Lead major optioneering, constructability, modularisation and plant integration studies.
- Lead complex multidisciplinary reviews and technical workshops.
- Provide technical assurance and review of layout deliverables.
- Lead resolution of complex layout, routing, requirements and integration challenges.
- Ensure layout solutions satisfy operational, safety, constructability and lifecycle requirements.
- Support bids, proposals and client engagement activities.
- Develop layout standards, procedures and best practice guidance.
- Mentor engineers and support capability development.
- Support recruitment, succession planning and capability growth.
- Author and review technical reports, engineering strategies and client-facing documentation
Why Apply?
Join Assystem and become a key player in delivering critical nuclear projects that shape the future of energy. Embrace this opportunity to excel in a dynamic environment where your expertise and leadership will drive global innovation.
Benefits include:
- Pension scheme (8% company contribution / 4% personal contribution)
- 25 days’ paid annual leave + bank holidays + option to buy or sell days
- Professional fees reimbursed
- Flexible working
- Employee referral scheme
Essential Skills, Qualifications and Experience
- Degree qualified in Mechanical Engineering or related discipline, or equivalent industrial experience.
- Extensive experience in plant layout, piping layout, plant integration and multidisciplinary engineering delivery.
- Experience leading complex engineering studies and technical decision-making.
- Strong understanding of systems engineering principles, requirements management and interface management.
- Strong understanding of constructability, maintainability, modularisation and lifecycle considerations.
- Experience leading multidisciplinary teams, workshops and design reviews.
- Experience supporting major design reviews, technical governance activities and engineering assurance processes.
- Experience using E3D, PDMS, Plant 3D, Siemens NX, Revit, Inventor and Navisworks, or equivalent platforms.
- Excellent report writing, presentation and stakeholder management skills.
- Proven ability to influence senior stakeholders, clients and project teams.
- Ability to define engineering strategy whilst remaining engaged in technical delivery.
- SC Clearance or capable of achieving it.
Desirable Skills and Experience
- Experience within the nuclear, fusion, SMR or AMR sectors.
- Experience supporting business development and client-facing activities.
- Experience developing engineering standards, methodologies and governance processes.
- Candidates able to demonstrate experience through technical leadership, engineering decision-making and delivery of complex engineering projects are encouraged to apply.
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.
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.