But why is it so hard. A steam engine in itself is not complex, we had locomotives for a long time, they didn't have high performance welding for example. Why can't we dumb down nuclear reactors? While keeping it safe. Perhaps by using material that won't cause meltdowns or using heat from nuclear waste?
If you have 20,000 welds that each need to last 30 years without being fixed later, that's an order of magnitude difference in quantity than the corresponding 2,000 for a coal boiler, in addition to a few orders of magnitude difference in the necessity of lasting a long time without repair.
It's a hell of a lot more than a steam boiler, even if ultimately that's the goal. The nuclear island is a hell of a beast of complexity, size, and quality.
