You need to compare the % of people driving cars vs dying on car accidents, vs the people working with highly radio-active material (without protection at the time) vs people dying from radio-active material under that specific conditions :-)
[1] http://www.forbes.com/sites/jamesconca/2012/06/10/energys-de...
A lot of the fatalities are from coal, not oil or natural gas. Coal is much more widely used than nuclear energy, so I'm not sure if they were used on the same amount which would have more casualties.
Not to mention that this depends on the country as well, since countries differ wildly in terms of workplace safety and the existence/enforcement of environmental standarts.
I would avoid repeating this claim.
The nuclear death rate is ~1/375 that of coal. This is because emissions are a major contributor to the death rate for coal.
Looking it up, the first analysis I find says that uranium ore is likely more energy dense than coal[1] so it shouldn't be the case that it is a lot more dangerous than coal mining.
Even back then, people were dying much more of traffic incidents than radioactivity exposure. Yet people fear radioactivity way more than taking their own car.