Gah! One of their reports within the past 5+ years. It was in an analysis of risks by major energy modalities. Unfortunately IPCC's content organisation is a disaster.

Analysis unit was deaths per GWh or similar.

I'll see if I can find it though I'm not optimistic.

Our World In Data posts similar stats, premature deaths/yr at 1 TWe/yr generation:

    Coal: 25
    Oil:  18
    Gas: 3

For the safer options, statement is inverted, as years for 1 death:

    Nuclear: 14--100
    Wind: 29 years
    Hydropower or solar: 42 years
    Solar: 53

Note w/h/s are all within the range of error for nuclear. (And why hydro isn't broken out separately I don't know.)

https://ourworldindata.org/safest-sources-of-energy