How does the cost of nuclear energy compare with that of energy generated by fossil fuels? A nuclear plant costs more to build than the typical coal-fired electric plant. Other expenses to be factored in include those for the disposal of contaminated wastes and the decommissioning of outdated plants. However, the fuel for a nuclear plant is much cheaper than fossil fuel. Accounting for all these factors, electricity from nuclear power plants costs the same or even less than energy from plants using fossil fuels.