Uncertainties in power plant design point evaluations

When designing a new large experimental device, extrapolation from current knowledge and scaling laws into unexplored design space is unavoidable, and predicting the behaviour of a new device is therefore subject to significant uncertainties. This makes it difficult to determine an optimal design. For conceptual fusion power plants, a further concern is whether the expected performance will yield any net electricity and for pulsed power plants a reasonable pulse length. In this work, we focus on evaluating the effects of selected uncertainties regarding the general plasma physics performance in the current European pulsed DEMO design (nominally 500 MW net electrical power, 2 h pulse length). This is meant as a first step towards uncertainty quantification for DEMO. We use a Monte-Carlo method in combination with the systems modelling code PROCESS to map out the probable machine performance. The results show that assuming only these specific uncertainties it is a reasonable assumption that the current design is capable of providing 400 MW of net electricity while maintaining a pulse length of 1 h or more.