Nuclear Energy

The intensive developments in advanced nuclear energy (SMRs, AMRs, and Generation IV) requires innovative solutions to overcome the demanding radiological environments to achieve commercialisation. Oxford Sigma holds expertise in advanced nuclear reactor technology, develops materials engineering solutions, and has experience in regulatory compliance.

We work in three main areas in nuclear energy, these include reactor core engineering, alternative coolant technologies, and consultancy.

Reactor Core Engineering

Advanced nuclear reactors are exposed to corrosive environments, create intense radiation damage, and operate at high temperatures.

Oxford Sigma holds leading knowledge in materials science, nuclear engineering, and regulatory processes. This enables us to tackle these challenges towards achieving design substantiation.

Reactor Core Engineering
Alternative Coolant Technologies​

Alternative Coolant Technologies

Advanced nuclear reactor designs that use alternative coolants are able to achieve high temperature operation and hold superior inherent passive safety features.

We specialise in alternative coolant technologies, including liquid lead, liquid sodium, and molten salt. Our capabilities range from materials development and coolant dynamics to degradation analysis and regulatory compliance, among others.

Office for Nuclear Regulation

ONR Technical Support Framework

The Office for Nuclear Regulation (ONR) is the regulator for the nuclear industry in the United Kingdom. Oxford Sigma is proud to be an approved supplier (Tier 2) on the ONR’s Technical Support Framework. We support Frazer-Nash Consultancy Ltd’s Tier 1 position on the framework in advanced nuclear reactor designs, SMR technology, structural integrity, and fuel design.

Please visit the ONR website for more information about the framework.


Oxford Sigma offers consultancy services in the following areas related (but not exclusive) to nuclear energy:

  • Reactor core engineering.
  • Structural integrity assessments of Systems, Structures, and Components (SSCs).
  • Application of nuclear design codes (e.g. ASME BPVC).
  • Nuclear materials engineering (e.g. austenitic and ferritic steels, silicon carbide, nickel-based alloys and oxide-dispersion strengthened steels).
  • Sodium, lead, lead-bismuth, helium, and molten-salt coolant technologies.
  • System integration.
  • Design optimisation.
  • Mechanical engineering.
  • Supply chain engagement and manufacturing expertise.
  • R&D strategy development.
    Assessment of radiological hazards, neutronics, and waste streams (e.g. MCNP, OpenMC, and FISPACT-II).
  • Safety & environmental case management.
  • Nuclear regulatory compliance and strategy.
  • Hazard and accident identification techniques (e.g. HAZOP).
  • Training courses on advanced nuclear energy.
For more information on our consultancy services, please contact us via email at [email protected].