The MIT Center For Advanced Nuclear Study released a report on The cost of electricity in May (2009).
The three cost elements used in the study are capital, operation and management, and fuel.
Incorporating all cost elements, the study found that the levelized cost of electricity, denominated in 2007 dollars, are as follows:
nuclear power is 8.4¢/kWh [includes the risk premium (safety tax) which makes capital costs much higher than coal or gas]
coal is 8.3¢/kWh [includes a $25/tCO2 charge (carbon tax)]
Gas-Fired Power 7.4¢/kWh [includes a $25/tCO2 charge (carbon tax)]
There are two very important factors to consider here. The first is that safety regulations are much more severe and costly for nuclear power plants than they are for either coal or gas-fired power plants. This CANES study takes this into account and concludes that if you equalize the safety restrictions, the levelized cost of electricity, denominated in 2007 dollars, from nuclear power is 6.6¢/kWh.
Many people who oppose nuclear power plants consider them more hazardous than coal or gas-fired power plants. Please see my post which clearly explains how safe pebble bed reactors are and see my posts about background radiation and how dangerous coal clearly is.