Case study

Bio-shield design

A tailored structural design, providing flexibility within existing construction constraints, while enabling radiation protection for workers.


Frazer-Nash Consultancy were approached by a UK nuclear fusion company to assist in the design of a structure to surround their tokamak nuclear fusion reactor and contain and absorb nuclear emissions, in the form of neutron and gamma rays.

The structure would have to be constructed around the already installed reactor and equipment, whilst maintaining adherence to safe working standards during and after construction. The shield structure would have to fit within the warehouse that the reactor was situated in, as well as accommodate the various electrical and cryogenic services that feed into the reactor.

To meet the construction constraints, our design made use of prefabricated concrete blocks to provide the flexibility to tailor the design to fit within the warehouse and around the nuclear reactor, whilst maintaining a safe place to work. These blocks could then be lifted by the client’s existing overhead crane and placed safely, with control and accuracy. The required thickness and material composition of concrete to provide adequate protection against the emitted radiation was then determined, and the walls were designed to allow installation independent to other walls, providing construction flexibility for the client.

Structural analysis was also conducted on blocks used as lintels over penetrations and access doorways, which were constructed from steel and filled with boronic sand to provide personnel access into the bio-shield whilst providing safe emission protection. Metallic frames that could support the weight of concrete blocks, as well as be backfilled with boronic sand, were designed to allow the passing of services through penetrations with sufficient radiation protection. 

Frazer-Nash Consultancy supported the client by providing an embedded engineer to help the client progress with the detailed design, testing and installation of their nuclear reactor.

Work with Frazer-Nash

Get in touch and let us help with your next project