Principal Mechanical Engineer – Nuclear Power Systems Lead

Assystem UK Ltd; Olney; Hybrid; GBP 75,000 - 110,000; Full time

Benefits offered by this job

Hybrid work 1-2 days remote per week

Ongoing training & career development

Holiday bonuses

Employee Committee

Job summary

Assystem UK Ltd is seeking a Principal Engineer to lead Front Engineering activities for Small Modular Reactors, Advanced Modular Reactors and Fusion projects. You will work with multi‑disciplinary teams, delivering the engineering design scope and guiding a dedicated engineering group.

Your mission includes spearheading the delivery of cutting‑edge power station systems and taking charge of optioneering, ensuring ALARP compliance and robust safety cases across complex projects.

Qualifications

• Experience in highly regulated industries such as nuclear, thermal power, or oil and gas.
• Proven ability to lead design teams and deliver Front Engineering for SMR/AMR and fusion projects.
• Strong optioneering skills with experience crafting ALARP and BAT arguments.
• Mentoring and developing junior staff; leadership in small teams.

Responsibilities

• Lead engineering design teams and deliver FEED activities for SMR, AMR and Fusion projects.
• Chair design reviews and ensure safety, quality, and compliance across disciplines.
• Drive optioneering and integration of systems into plant infrastructure; ensure compliance with standards.

Skills

Nuclear industry experience

Optioneering

Leadership

Communication

Systems engineering

ALARP/BAT arguments

Mentoring

Tools

ASME standards

UK/EU codes

Job description

Assystem UK Ltd is seeking a Principal Engineer to lead Front Engineering activities for Small Modular Reactors, Advanced Modular Reactors and Fusion projects. You will work with multi‑disciplinary teams, delivering the engineering design scope and guiding a dedicated engineering group.

Your mission includes spearheading the delivery of cutting‑edge power station systems and taking charge of optioneering, ensuring ALARP compliance and robust safety cases across complex projects.