Innovate UK

Innovate UK is the UK’s innovation agency, part of the Department for Business, Energy and Industrial Strategy, that works with people, companies and partner organisations to find and drive the science and technology innovations that will grow the UK economy.

Businesses and research organisations can apply to Innovate UK funding competitions to help them develop their innovations. You can apply for funding to test the feasibility of your idea, research and develop it and demonstrate it in a prototype.

Case Study | Developing the Civil Nuclear Supply Chain

Three School of MACE projects were funded through a competitive call from Innovate UK on “Developing the Civil Nuclear Supply Chain”. These considered theoretical and experimental aspects of irradiation damage, mechanical behaviour, and fracture. The value of these three projects to the University was £1.6M out of a total budget in excess of £3.5M.

 

Project overview

The graphite core in nuclear Advanced Gas cooled Reactors (AGRs) provides channels for fuel positioning and cooling, and shut-down/control rod insertion. As the reactors age, the graphite within the core degenerates, leading to the local cracking of components. As a consequence damage tolerance assessments are needed to establish whether an adequate margin remains for the integrity of the fuel and proper behaviour of the safety systems.

The development of reliable numerical tools was needed for safe plans for life extension of the reactor fleet. In addition, the outcomes would aid design and expected lifetimes for the next generation of nuclear plants.

Project outputs

A numerical tool was developed that predicted the crack shape in 3D from the complex geometry of a fuel brick. It was written in an open source code (Code_Aster) meaning that it is available to the whole scientific community. It looks at the energy and stress state ahead of the crack tip and predicts the crack path.

To aid more reliable constitutive relationships as input for stress calculations, a world-first experiment was performed at the Diamond Light Source, a synchrotron X-ray source just outside of Oxford, where the coefficient of thermal expansion of irradiated graphite was measured under load. This key parameter is needed to better understand the change in conditions between running the reactor and shutting it down for inspections. This helped provide greater confidence on the predictions of damage progression in the reactor core, leading to safer claims for life extension.

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