This wikipedia page captures numerous methods of measuring it and you can see the variety of results. There's only one study where solar is considered more expensive than nuclear (ipcc 2014 which was before solar panel prices dropped like a stone) https://en.m.wikipedia.org/wiki/Cost_of_electricity_by_source

Levelized cost of energy seems to be the common metric https://www.reuters.com/article/us-energy-nuclearpower/nuclear-energy-too-slow-too-expensive-to-save-climate-report-idUSKBN1W909J