So we need 4400 persons falling off a roof to be par with nuclear power plants. I still consider this ratio a much better outcome than a power plant going off anywhere near (radius to be defined in Mm depending on wind direction).
How? There has been a handful of nuclear plant accidents ever, but hundreds of thousands of people work on roofs every year worldwide to install solar panels.
As far as I can tell, the original pro-nuclear "deaths per TWh" calculation, and follow-up work, neglects mundane industrial accidents that occur during the construction and operation of nuclear power plants. Only incidents involving unplanned radiation exposure are counted. But these same kinds of mundane accidents do get counted in the numbers for renewable energy. Further, as I note in another comment, the solar PV numbers neglect that more TWh come from solar farms than from rooftop solar installations, and that constructing solar farms is safer (lower risk of fatal falls). The methodological difference isn't significant if you just want to highlight how dangerous the fossil fuel status quo is compared to non-combustion options. But if you want to compare deaths-from-renewables vs. deaths-from-nuclear, it doesn't make sense to omit the mundane accidents from just one side of the balance sheet.
As an example of "mundane" nuclear deaths, 6 workers have been killed at the Surry Nuclear Plant. 2 were fatally scalded by an accidental steam release in 1972. 4 were killed by a steam explosion in 1986.