A typical third-party liability insurance cap for large hydroelectric dams ranges from $50 million to $100 million per occurrence, with major facilities stacking excess liability layers well beyond that.
Dam failures can cause very large costs. The 2015 Fundão tailings dam breach:
" On 25 October 2024, mining companies BHP and Vale signed an agreement with the Brazilian government to pay nearly US$30 billion in compensation over the Mariana Dam collapse. The terms include $18 billion in funding for public authorities and $5.6 billion in additional compensation, resettlement, and environment restoration. "
https://en.wikipedia.org/wiki/Mariana_dam_disaster#Governmen...
1975 Banqiao Dam failure, Deaths 26,000–240,000. Property damage: 62 dams collapsed, more than 5 million houses collapsed, 10.75 million people affected
https://en.wikipedia.org/wiki/1975_Banqiao_Dam_failure
For sabotage in Europe, I would be much more worry about security of hydro dams, chemical facilities and water supply. They are much more weakly protected then nuclear power plants.
https://www.nrc.gov/regulations-legislation/fact-sheets-broc...