The New Scientist calculated the number of deaths per kilowatt-hour question based on the data from International Atomic Energy Agency in 2011.

• https://www.newscientist.com/article/mg20928053.600-fossil-fuels-are-far-deadlier-than-nuclear-power/
• https://www.iaea.org/

According to the New Scientist:

The agency examined the life cycle of each fuel from extraction to post-use and included deaths from accidents as well as long-term exposure to emissions or radiation.

They concluded that "fossil fuels are far deadlier than nuclear power" and that "the large number of deaths [related to fossil fuels] are caused by pollution."
[https://i.stack.imgur.com/uglxE.jpg]

Another, more recent, report supporting these numbers can be found at the World Nuclear Association, here. http://www.world-nuclear.org/information-library/energy-and-the-environment/environment-and-health-in-electricity-generation.aspx

An article in Forbes gives the following numbers, which I reproduce here in their simplified form: https://www.forbes.com/sites/jamesconca/2012/06/10/energys-deathprint-a-price-always-paid/#571bf970709b