I believe the construction cost of a containment dome is a drop in the bucket in comparison to the overall system construction, maintenance, and operation costs. I think it would be a foolhardy decision to eliminate them.
Putting a power plant in remote location will require longer transmission lines. Not only do you have to pay for the construction of these lines, but you also have to pay for their maintenance. Furthermore, longer lines also mean greater power loss due to resistance. I'm willing to bet the cost savings realized by building closer to the population centers will more than pay for the cost of a containment dome.