Yes, building reactors is too expensive. However, that's mostly because the people building them in the US are utterly incompetent (source: I'm a Georgia Power ratepayer on the hook for Plant Vogtle 3 and 4) and also because every project has to fend off an army of unfounded lawsuits from misguided environmentalists.
The waste issue is mostly just fake: not only do we have a perfectly good place to put it that we refuse to use for stupid reasons, even that was unnecessary to begin with because we should be reprocessing it instead.
Define 'waste'. Depending on the plant design, a good chunk of the cooling is achieved by evaporating cooling water into the atmosphere. That could be waste.
Does the air blown through a wind turbine count as waste going into the atmosphere? Same for hydro going downriver?
I'm going to call this a stupid argument: we treat waste with the level of care the waste deserves, CO2 notwithstanding (and carbon capture being junk). Nuclear is expensive partly because its waste actually needs to be dealt with carefully.
Insurance, sustainability, waste, catastrophic risks, centralisation are all factors against nuclear energy and everything considered, I wouldn't call it clean.