A novel steel–concrete composite system for modular nuclear reactors

Small modular nuclear reactors offer an opportunity to develop innovative design and construction techniques with the aim of maximising factory prefabrication and transportability of prefabricated units, and of facilitating their site assembly. This can be achieved through designs that incorporate advanced modular construction techniques. This paper provides an overview of the work undertaken to develop an innovative form of composite steel–concrete modular construction. The basic building block of the system is a steel plate folded into a U-shape with a concrete infill. Individual building blocks – called ‘steel bricks’ – can be joined together to create larger units that make up the modules of a small modular reactor. The work addresses the application of Eurocode design rules to structural elements constructed of steel bricks, as well as all the key manufacturing operations including plate folding; joining of units together; lifting of units; stability during erection; alignment and manipulation; joints between panels; connection to reinforced concrete foundations; and quality assurance and inspection techniques. The concept is being demonstrated at full scale through the construction of a section of a diesel generator building.