Engineer - Thermal Hydraulics

You’ll be joining a forward-thinking organisation that values transparency, fairness, and innovation. We offer:

• A flexible, inclusive, and supportive working environment.
• Opportunities for career growth in a rapidly scaling business.
• A culture that values diversity, innovation, and continuous learning.

We are an equal opportunities employer and welcome applications from all backgrounds. Inclusivity is important to us, and as a Disability Confident organisation, we are committed to fair, supportive, and continually improving recruitment practices that ensure everyone has the opportunity to thrive.

Confidence can sometimes hold us back from applying for a job. But we'll let you in on a secret: there's no such thing as a 'perfect' candidate. If you feel you meet 75% of the requirements for this role, we would love to hear from you. Also, if you are considering a career move or a sector-jump, please get in touch – we welcome applications from people with transferable skills.

Due to the safety regulations within the nuclear industry, applicants will be required to participate in additional screening. These are:

• Obtaining Baseline Personnel Security Standard (BPSS) clearance
• Satisfactory completion of a Disclosure and Barring Service (DBS) check
• Satisfactory completion of a basic financial probity check

The Performance & Analysis team is the centre of excellence within Rolls-Royce SMR for the engineering analysis used to substantiate the performance and safety of the power station. Multiple opportunities are open across all areas of thermal‐hydraulic plant performance and safety analysis including reactor plant transient and fault analysis, core sub‐channel analysis and containment analysis.

As a performance analyst, you will model the thermal-hydraulics of the containment and its associated emergency cooling systems. This includes producing models and analyses that demonstrate the effectiveness of containment and its safety systems under faulted conditions, and working closely with system designers to optimise the plant design and safety systems to maximise safety, performance and value for money. Analysis outputs form a key input to the safety case and support the overall substantiation of the power station design. Performance analysts also support the development and authoring of analysis sections of the safety case.

You will work with a wide range of tools and software to analyse plant scenarios, including:

• Normal operations, when the reactor must produce power and respond to grid demand
• Operating transients such as shutdown and restart for refuelling
• Reactor faults, where passive safety systems protect the core and ensure containment integrity

Due to the safety-critical nature of the modelling we undertake, excellent quality‐management processes and code verification, validation and uncertainty quantification are essential. Development of robust and automated analysis routes (primarily in Python on Linux-based HPC systems) is an important part of this role. Performance engineers ensure quality through rigorous process adherence, supporting code validation activities and continuous improvement of tools and methods.

You will collaborate closely with our in‐house test capability team who are building large-scale, multi‐megawatt test rigs to support validation of performance analysis tools. Opportunities include benchmarking our codes against test data and supporting the development of test rig designs and campaigns. Cross-functional collaboration is essential. Staff should be flexible and proactive in communicating results, developing analysis requirements and supporting design development across engineering and non‐engineering disciplines. Depending on your experience, you may also support technical capability development or lead technical areas and interfaces.

• Model thermal‐hydraulic behaviour of containment and emergency cooling systems
• Produce structured analyses to support the safety case and design substantiation
• Collaborate with system designers to optimise safety system performance
• Support code verification, validation and uncertainty quantification activities
• Develop automated analysis routes and tools (often Python‐based)
• Contribute to benchmarking activities and test rig development
• Plan and manage your own work to meet quality, cost and schedule objectives

• Strong understanding of fluid dynamics and thermal processes, with experience applying structured, methodical approaches to analysis
• Hands-on experience using industry-standard fluids and thermal analysis software
• Desirable but not essential to have experience of nuclear industry thermal hydraulics analysis methods and tools: Reactor Plant Systems Analysis (RELAP, FLOMASTER), Core Sub-channel Analysis (VIPRE, CTF), Containment Analysis (GOTHIC).
• Proven ability to develop analysis methods, models and tools, including Python‐based solutions
• Skilled in writing clear, structured analysis reports and contributing to safety case documentation
• Experience in verification and validation of analysis models, including benchmarking, uncertainty quantification and adherence to software QA processes
• Knowledge of safety‐critical plant systems (nuclear, oil & gas, aerospace desirable but not essential)
• Track record of delivering analysis tasks to time, cost, and quality, with strong communication and leadership skills
• Degree-qualified in Engineering, Physics, Mathematics, or Computer Science; Chartered Engineer (or equivalent) preferred

Hybrid working with one of the following locations as your primary site: Manchester, Derby or Warrington.

The salary band for this will be between £42,000–£55,150 dependent on the skills, values, and knowledge you bring. There may be some flexibility with the starting salary in exceptional cases, and, in due course, there is the potential for you to develop the role further.

Benefits include:

• Bonus - Performance-related target opportunity 12.5%
• Benefits Allowance - £2,200 per annum for a bespoke package
• Pension - 12% employer and 6% employee contributions
• Holidays - 28 days (+ public holidays) with ability to buy or sell up to 4 days
• Private Medical Insurance - BUPA single cover
• Life Assurance - 6x pensionable pay
• Home Office Support - £250 one-off payment for new starters

The closing date for this role is 6th April 2026. The process will then consist of an introductory call with the Talent Acquisition Partner, and we anticipate shortlisting and first‐round interviews to take place shortly after.

A career with Rolls-Royce SMR offers a unique opportunity to contribute to an exciting organisation delivering a transformational mission. Rolls-Royce SMR is a radically different approach to proven nuclear technology. Each Rolls-Royce SMR power station will generate 470MW of low-carbon energy - equivalent to more than 150 onshore wind turbines and enough to power a million homes for over 60 years. With its Rolls-Royce SMRs will play a vital role in supporting renewable energy by helping to overcome intermittency.