In the grand scheme of things, that doesn't seem to be too expensive. According to the NRC, insurance is per site, and additional reactors on a site don't increase the insurance nearly as much as the first. The example they give is $1.1 million annual premium for a $500 million policy, with multi-reactor sites going up to $1.5 million. They also mention property insurance ($1.06 billion policy) and they didn't discuss the premiums on that, but as it's not liability insurance it's probably cheaper.

The big costs are still going to be the cost of siting and building the reactor, the fuel, and the ongoing cost of running it. They pay off over a very long time horizon, so it's also the opportunity cost.

https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/n...