It would be good if readers could find details on that; and also on possible load-following operation in Sweden or Spain.

Not easy to find. The common wisdom is that nuclear power (65-70 TWh) is base load and hydro (50-75 TWh) is both base and top load. The only solid thing I found was a report from Vattenfall on something else that mentioned reactors running at reduced load in the summer. It was just a sentence and could possibly referred to scheduled maintenance in the summer.

Sweden has a lot of hydro and I would see little need for using nuclear as intermedient power here. Especially as I agree that starting them puts them at risk.

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