[T]he report’s executive summary certainly gets to the heart of their findings.
“The rhetoric from small modular reactor (SMR) advocates is loud and persistent: This time will be different because the cost overruns and schedule delays that have plagued large reactor construction projects will not be repeated with the new designs,” says the report. “But the few SMRs that have been built (or have been started) paint a different picture – one that looks startlingly similar to the past. Significant construction delays are still the norm and costs have continued to climb.”
Nuclear reactors are ill-suited for baseloads, because they can’t scale their output in an economical way.
You always want the cheapest power available to fulfill demand, which is solar and wind. Those regularly provide more than 100% of the demand. At this point, any other power sources would shut off due to economical reasons. Same with nuclear, nobody wants to buy expensive nuclear energy at peak solar/wind hours, so the reactor needs to turn off. And while some designs can fairly quickly power down, powering up is a different matter and doing either in an economically feasible way is a fantasy right now.
If solar and wind don’t provide enough power to satisfy demand, some other power source needs to turn on. Studies have already shown that current-gen battery storage is capable of doing so. Alternatives could be hydrogen or gas power stations. Nuclear isn’t an option economically speaking.