Reactor System Design Engineer Job Leicester area,East Midlands England UK,Engineering

ALTEN is a global engineering and technology consultancy operating across over 35 countries worldwide. We partner with industry leaders across sectors including Aeronautics, Aerospace, Defence, Naval, Automotive, Energy, Rail, IT and many more to deliver innovative engineering solutions that drive technological advancement & support sustainable transformation.

Our teams of passionate and agile engineers work on cutting‑edge projects that shape the future of technology and sustainability. At ALTEN, we empower talented engineers to innovate, solve complex challenges, and deliver impactful solutions that build tomorrow’s world—today.

Join us and start building tomorrow’s world today!

Job Description

We are seeking a talented Reactor System Design Engineer to join a highly innovative engineering team working on the development of next‑generation nuclear technology.

This role will focus on the design and development of Reactor Island systems
, including primary and secondary circuit systems, from early concept definition through to detailed design. You'll work with in a multidisciplinary environment, collaborating with technical specialists and stakeholders to develop safe, efficient, and compliant system architectures.

This is an excellent opportunity for a Process Engineer or System Design Engineer with 4-8 years' experience looking to work on complex, high‑impact engineering projects.

Key Responsibilities

Lead the design and development of Reactor Island systems, including primary and secondary circuit systems.
Develop system concepts and mature designs through both concept and detailed design phases.
Produce and maintain key design documentation, including:
- System Design Descriptions (SDDs)
- Requirements Specifications
- P&IDs
- Functional Bills of Materials (FBoMs)
- Engineering calculations
- Decision logs and optioneering studies
Define system requirements and develop compliant system architectures.
Conduct technical calculations for system and component sizing.
Engage with multidisciplinary stakeholders to ensure requirements are captured and integrated effectively.
Present technical design solutions at formal design reviews and stage‑gate assessments.
Ensure designs meet safety, regulatory and operational requirements through the application of Design for X principles.

Qualifications Required Skills

4-8 years' experience in process or systems engineering.
Experience applying process system design principles on complex engineering projects.
Ownership of system designs through concept and detailed design phases.
Experience producing:
- System requirements
- System description/design reports
- Process flow diagrams
- P&IDs
- Engineering calculations
Strong technical stakeholder management and cross‑functional collaboration skills.
Experience carrying out system optioneering and technical trade‑off studies.

Required Qualifications

A Bachelor’s or Master’s degree in Engineering
, or equivalent
military experience
.

Desirable Skills

Nuclear industry experience.
Sampling systems design experience.
Experience with reactor, thermal‑hydraulic, utility, or process…