Nuclear fusion is seen as a possible future electricity source with much potential. However, the developments still have a long way to go and there are many uncertainties on the path towards realizing this potential. This study performed a qualitative analysis of uncertainties for fusion development as a first step in addressing the uncertainties. The study was performed in the context of the European research roadmap to the realization of fusion energy, focusing on the development of tokamaks. Eighteen uncertainties were identified by means of a literature study. A layered classification framework from the context of product development was used and adapted to systematically classify these uncertainties. The result can serve as a basis for developing approaches to address the uncertainties.

The categories of uncertainties addressed are: technical, industrial, political/social, and market uncertainties.