There have been some pretty spectacular oil rig disasters with huge oil spills and >100 direct deaths. I would count those on the same scale. And those are in addition to the huge numbers of deaths every year and the contribution to global warming.
I wouldn't, though, because they don't have the impact on the population at large and don't cost nearly as much. Yes, maybe they impact other industries or recreation in an area for awhile.
A fossil fuel plant operating nominally without any incidents will impact the entire population as the fossil fuels are consumed and the byproducts of their combustion emitted. The number of QALYs / DALYs / deaths lost that are directly attributable to air pollution is absolutely staggering.
The magnitude of the risks we're contemplating when we're discussing nuclear are completely insignificant in relation to that.
