Senior Nuclear Systems Engineer

Holtec International; Almondsbury; On-site; GBP 90,000 - 120,000; Full time

Job summary

Holtec International seeks a Senior Nuclear Systems Engineer to act as the technical authority for Nuclear Island systems, independently leading system-level design, integration, and licensing activities within a highly regulated program.

You will mentor junior engineers, drive system requirements, and collaborate with licensing, safety, and manufacturing teams to deliver safe, compliant plant designs for the SMR-300 project.

Qualifications

• 8+ years of progressive engineering experience.
• Experience as system owner or lead engineer for safety-related Nuclear Island (NI) systems on a nuclear plant.
• Mentor and develop junior engineers; review designs, calculations, and system-level deliverables.
• Strong fundamentals in heat transfer and fluid dynamics; apply to complex plant systems.

Responsibilities

• Lead multi-disciplinary system engineering and integration activities across major SMR-300 plant systems.
• Develop and manage system requirements, interface definitions, and component specifications.
• Mentor engineers and review calculations, specifications, and technical deliverables.
• Perform analyses and calculations in thermal-fluids and overall plant system performance.
• Coordinate with licensing, safety, and regulatory teams to support safety case development.
• Collaborate with internal teams, suppliers, and manufacturing partners to ensure designs are sound and executable.
• Support design reviews and internal approvals aligned with milestones and quality standards.
• Serve as technical lead for assigned Nuclear Island systems and own system integration and cross-discipline alignment.
• Deliver system-level engineering scope for the SMR-300 program with high safety and regulatory rigor.

Skills

Leadership

Mentoring

Technical writing

Stakeholder engagement

Communication

Education

Bachelor’s degree in Engineering

Master’s degree preferred

EIT/PE certification preferred

Tools

SmartPlant

Mathcad

AutoCAD

Pipe Flo

HTRI

ELM

DOORS NG

Job description

Senior Nuclear Systems Engineer supports the development of a next‑generation nuclear power plant as part of a multidisciplinary engineering team responsible for Nuclear Island (NI) systems‑level design. This role is intended for experienced engineers who can act as a technical authority for assigned NI systems, independently leading system‑level design, integration, and licensing activities while mentoring junior engineers in a highly regulated environment. Supporting the SMR‑300, this position works closely with engineering, manufacturing, and licensing teams as part of a U.S. Government cost‑shared development program, developing system requirements, specifications, analyses, and design documentation to support safe, compliant, and executable plant designs.

Location: Almondsburry, UK or Madrid, Spain

Primary Responsibilities

• Lead multi‑disciplinary system engineering and integration activities across major SMR‑300 plant systems, ensuring technical consistency and alignment across engineering disciplines
• Develop and manage system requirements, interface definitions, and component specifications to support detailed design, analysis, and licensing activities
• Serve as a technical mentor to early‑career and mid‑level systems engineers, providing design guidance and reviewing calculations, specifications, and technical deliverables
• Perform and oversee engineering analyses and calculations, particularly in areas related to thermal‑fluids and overall plant system performance
• Conduct and support technical trade studies and design evaluations that inform high‑impact decisions affecting plant architecture, safety, and performance
• Coordinate closely with licensing, safety, and regulatory teams to ensure system designs support safety case development and meet applicable codes and regulatory expectations
• Collaborate with internal engineering teams, suppliers, and manufacturing partners to ensure system designs are technically sound, manufacturable, and executable
• Support technical reviews, design documentation development, and internal design approval processes in alignment with program milestones and quality standards
• Serve as a technical lead for assigned Nuclear Island systems, owning system integration, requirements, and cross‑discipline alignment.
• Execute assigned system‑level engineering scope for the SMR‑300 development program, delivering work with a high standard of quality, safety, and regulatory rigor

Requirements

• Bachelor’s degree in Engineering (Mechanical, Nuclear, Electrical, or related discipline); Master’s degree preferred
• 8+ years of progressive engineering experience, with demonstrated growth in technical responsibility and scope
• Prior experience serving as a system owner or lead engineer for safety‑related Nuclear Island (NI) systems on an operating or new‑build nuclear power plant strongly preferred
• Demonstrated experience mentoring and technically developing junior engineers, including review of designs, calculations, and system‑level deliverables
• Proven ability to lead multidisciplinary engineering teams, resolve highly complex technical issues, and drive system‑level decisions
• Strong fundamentals in heat transfer and fluid dynamics, with demonstrated application to complex plant systems
• Experience developing engineering designs, specifications, drawings, and technical requirements in collaboration with engineers, suppliers, and manufacturers
• Experience working in the nuclear energy industry in a system design or systems engineering capacity preferred; candidates with aerospace, defense, or other regulated‑industry systems experience also encouraged
• Familiarity with engineering and design tools such as SmartPlant, Mathcad, AutoCAD, Pipe Flo, HTRI, Engineering Lifecycle Management (ELM), and requirements management tools (e.g., DOORS NG) preferred
• Excellent technical writing, communication, and stakeholder engagement skills
• Proficiency in Microsoft Office applications, particularly Word and Excel
• EIT and/or PE certification preferred

A Generation Ahead by Design

Investing in people who power the future.

Benefits

We believe great work deserves great rewards. Our benefits go beyond the basics, reflecting our commitment to supporting your whole self…your health, your future, and your career growth. This includes: