Digital Reactor Design: Nuclear Thermal Hydraulics

Securing skills and developing models through Nuclear Thermal Hydraulics research and innovation in the UK for SMRs and advanced reactor technologies


This project addresses key challenges in understanding and predicting the performance of thermal hydraulic processes for advanced reactor designs, and increasing industry skills in modern digital methods. This is part of the Nuclear Innovation Programme (NIP), which is funded by the UK government’s Department for Business, Energy and Industrial Strategy (BEIS).

This work considers all advanced nuclear technology coolants (water, helium, lead, sodium and molten salt).

Phase 1 (Complete)

Identified areas of thermal hydraulics research and development in the UK through:

  • Review of worldwide facilities and current research
  • User requirements capture
  • Specification of UK facility and model developments
  • Initial innovative research.

Phase 2 (Underway)

This will improve UK capability to model single phase heat transfer and natural convection in advanced nuclear technologies by delivering:

  • Technical volumes describing good practice
  • Industrial case studies
  • Focussed Research and Development (R&D)
  • Integration and dissemination.


Modelling reactor thermal hydraulics with confidence is essential to designing advanced reactors. Improved thermal hydraulic modelling capabilities will lead to:

  • Improved performance
  • Improved reliability
  • Reduced cost and time to market
  • Improved international collaboration.

By delivering this portfolio of R&D we can play our part in helping to realise low-carbon generating advanced nuclear technology.

Unplugged lightbulb with light omitting from it, on a wood background

Advancing reactor thermal hydraulics modelling to aid the design and development of future reactor designs.


A two-day event will be held in 2021 to present the outcomes of this programme and publish the technical volumes and case studies. Bookmark this page, and check back later this year for further details and to register.

Frazer-Nash will be attending the following nuclear industry events. Our planned events include:

Contact Us

Contact Name

Richard Underhill


1 Lower Lamb Street, Bristol, BS1 5UD, UK

Phone Number

+44 (0)117 9226242

Back to top