Senior Nuclear Thermal Hydraulics Consultant

Frazer-Nash Consultancy; West of England; Hybrid; GBP 71,000 - 82,000; Full time

Benefits offered by this job

25 days holiday

Hybrid working

Pension scheme

Private healthcare

Bonus scheme

Professional accreditation support

Cycle to work

Season ticket loan

Life assurance

Job summary

Frazer-Nash Consultancy is seeking a Senior Nuclear Thermal Hydraulics Consultant to shape safety analyses, support design decisions, and strengthen the UK’s civil nuclear capability. You will lead technical work packages, engage with clients, and contribute to proposals while mentoring junior engineers.

The role combines advanced modelling, regulatory engagement, and delivery of trusted consultancy across multiple projects, with a flexible hybrid pattern between office, client sites, and home.

Qualifications

• Demonstrable experience in nuclear thermal hydraulics supporting plant design/operations.
• Ability to interpret modelling outputs and communicate results clearly.
• Experience with safety cases and regulatory engagement.

Responsibilities

• Develop and maintain thermal-hydraulic models of nuclear plant systems.
• Analyse fault sequences, transients, and system behaviours to inform design decisions.
• Provide authoritative interpretation of model results to clients and regulators.
• Support model verification, validation, and best-practice application.
• Lead work packages and mentor junior engineers.

Skills

Thermal hydraulics

Nuclear engineering

Fluid dynamics

Heat transfer

Multiphase flow

Regulatory engagement

Education

Engineering/Physics/Applied Mathematics degree

Tools

RELAP

GOTHIC

CATHARE

TRACE

VIPRE

S5K

Job description

Title:

Senior Nuclear Thermal Hydraulics Consultant

Senior Nuclear Thermal Hydraulics Consultant

Salary range: £71,000–£82,000 per annum

Location: Manchester or Bristol

Working Pattern: We operate a flexible hybrid working model, with time split between the office, client sites, and home.

The Nuclear Renaissance is Here

From gigawatt‑scale reactors to next‑generation systems, the UK’s nuclear future depends on engineers who thrive on solving complex physical problems and delivering deep technical insight backed by robust analysis.

At Frazer‑Nash, our thermal hydraulics specialists sit at the heart of our work in nuclear safety, design, and assurance. We are seeking an experienced Senior Nuclear Thermal Hydraulics Consultant to help shape critical decisions, support safety cases, and strengthen the next generation of nuclear capability.

Your work will help to:

• Tackle safety‑critical engineering challenges
• Support confident regulatory and design decisions
• Strengthen the UK’s civil nuclear capability
• Deliver high‑quality, trusted consultancy advice to our clients

About Frazer ‑Nash in Nuclear

Frazer‑Nash has over three decades of experience supporting the UK nuclear sector. Our multidisciplinary teams work across civil nuclear operations, new‑build programmes and decommissioning, helping our clients meet exacting technical and regulatory requirements.

Our thermal hydraulics specialists work closely with safety, systems, and reactor engineers, providing insight into complex plant behaviour and supporting clients through design, justification, and regulatory engagement. We empower our consultants to take ownership of their work, build deep technical expertise, and have visible impact.

Why Join Frazer ‑Nash?

• Work on nationally significant nuclear programmes with real societal impact
• Take ownership of technically challenging work and client delivery
• Develop your career in a supportive, technically ambitious consultancy
• Be part of a collaborative team shaping the future of nuclear engineering in the UK

Why this Role?

As a Senior Nuclear Thermal Hydraulics Consultant, you will apply advanced analytical techniques and modelling tools to understand and explain complex thermal‑hydraulic behaviour in nuclear systems. You will contribute across the full consultancy lifecycle, from technical analysis and interpretation through to client engagement and business development.

Taking the lead

You will manage technical work packages, engage directly with clients, and support project delivery, while collaborating with supportive colleagues and mentoring and guiding less experienced engineers.

Variety of work

Our consultants typically work on multiple projects at once, ranging from short, focused studies to long‑term programme support across the nuclear lifecycle.

Growing capability

You will contribute to winning work, client discussions, and the continued growth of our thermal‑hydraulics capability across existing and emerging nuclear programmes.

Key responsibilities include:

• Developing and maintaining thermal‑hydraulic models of nuclear plant systems using industry‑standard codes,
• Analysing fault sequences, transients, and system behaviours to inform design decisions and nuclear safety cases,
• Providing authoritative interpretation of model results and underlying physical phenomena,
• Supporting model verification, validation, and best‑practice application,
• Communicating complex technical outputs clearly and concisely to clients, regulators, and internal stakeholders.

What We’re Looking For

Technical experience:

• Strong understanding of fluid flow, heat transfer, thermal hydraulics, and multiphase flows,
• A degree in Engineering, Physics, Applied Mathematics, or a related discipline, or equivalent relevant experience,
• Demonstrable experience in nuclear thermal hydraulics supporting nuclear plant design and/or operations (perhaps using codes like RELAP, GOTHIC, CATHARE, TRACE, VIPRE, S5K)
• Experience of transient and fault analysis within nuclear safety contexts,
• Ability to interpret, validate, and clearly explain complex modelling outputs.

Personal and consultancy skills:

• Ability to independently manage and deliver work to meet client requirements
• Experience contributing to proposal writing, client liaison, and business development
• Strong communication skills, with the ability to engage effectively through meetings, presentations, written reports, commercial bids, and technical discussions

Due to the nature of the work that Frazer‑Nash Consultancy undertakes, candidates will be required to undergo pre‑employment screening and must be able to satisfy clearance criteria for UK National Security Vetting.

Benefits

Our people are central to our success. We offer a comprehensive benefits package designed to support your wellbeing, development, and work–life balance, including:

• Competitive salary with annual reviews
• 25 days’ holiday, with the option to buy up to five additional days
• Flexible and hybrid working arrangements
• Enhanced parental benefits
• Company pension scheme
• Targeted professional development and career support
• Life assurance and private healthcare membership
• Bonus scheme linked to company performance
• Paid membership fees and support towards professional accreditation
• Cycle to Work scheme and season ticket loan
• A range of flexible benefits, tailored to your personal requirements