Analysis Driven Innovation Of A Fusion Power Plant Plasma Facing Component

Abstract

The STEP (Spherical Tokamak for Energy Production) Programme targets delivery of a UK prototype fusion energy power plant by 2040, to demonstrate a path to commercial viability of fusion power. A critical aspect to designing a fusion power plant is being able to extract useful energy out within the operating constraints of the plasma facing components, which must handle high heat fluxes over a sustained period. Increasing the heat loading capacity of these components widens the operating envelope for the plasma and ultimately enables high power outputs to be achieved. Key to enabling delivery of the STEP program, and ultimate realisation of commercially viable fusion power, will be the concurrent consideration of multiple component designs, including continued creation and exploration of novel concepts using appropriate analysis and simulation techniques to explore their feasibility efficiently and effectively. This paper presents innovative plasma facing component design concepts, providing an optimisation of the heat flux distribution and heat transfer, to increase the heat loading capacity within structural and thermal operating constraints, and in consideration of broader design objectives. Efficient simulation and analytical methods are developed and applied to optimise aspects of the design and explore the feasibility of solutions effectively, providing assessments of the thermal and structural performance in comparison to a more conventional design. Specifically, the analysis is used to quantify how the increased design freedom from optimisation can be exploited, such as reduced material quantities, increased heat flux operating window or increased component lifetime. The paper also demonstrates the value in using an analytical approach to aspects of design innovation to readily evaluate the feasibility and potential for novel design concepts. Finally, the paper outlines the main design challenges and further research and development work needed to explore the potential of the design concepts further, requiring expertise and involvement from wider industry.