Nuclear and renewable energy are at the forefront of the global transition towards low-carbon electricity generation. But while the share of renewable sources in the total global electricity mix has demonstrated tangible growth this past decade, the share of nuclear energy has remained stagnant. Despite a revived interest from governments worldwide, total nuclear output is even expected to drop in the coming years. In this article, we investigate the techno-economic challenges of combining high shares of renewable and nuclear electricity, which lies at the base of this issue. We discuss intermittency issues in a renewable-dominated electricity system, and the challenges of conventional nuclear generators in dealing with this variability. We take Belgium as an exemplary case, as nuclear generation currently generates up to 50% of its national electricity generation while the government is pushing a massive increase in renewable electricity generation. We simulate the European interconnected Belgian electricity system with a 2030 horizon to investigate if and how nuclear power and renewable energy can coexist, and in particular which market circumstances are required. ; This is a conference paper, presented on 18th International Conference on the European Energy Market, 13-15 September 2022, Ljubljana, Slovenia.