Just scanned a new article by Kristin Shrader-Frechette in Science and Engineering Ethics. She provides evidence from 30 nuclear power cost estimates and shows that the industry consistently ignores certain costs, trims others and generally makes estimates of other parameters which make the final result appear favorable to the nuclear industry.
She attributes the underestimates of cost that result from these studies are most likely due to the obvious conflict of interest that industry-funded studies encounter. Further, most of the data are provided by the industry themselves, and many are shielded under proprietary privilege.
In any case, a very nice piece of work with interesting parallels for others in the energy sector.
Shrader-Frechette, K. (2011). "Climate Change, Nuclear Economics, and Conflicts of Interest." Science and Engineering Ethics 17(1): 75-107.