Unless there is a leak at the nuclear power plant, nothing will happen. Fukushima and Chernobyl had a large and healthy population in nearby residential communities.
Including the Three Mile Island, Chernobyl, and Fukushima incidents in the United States, countries and regions with nuclear power plants attach great importance to the safety of nuclear power plants, and their monitoring equipment is better than before. However, if you are really worried about living 20 kilometers away from a nuclear power plant, generally even if an accident occurs, it will have no impact.