Final answer:
The subject of this question is Physics, and the answer discusses the Three Mile Island and Chernobyl accidents in relation to nuclear power plants.
Step-by-step explanation:
The subject of this question is Physics and the grade level is High School.
The quote in the question refers to nuclear power plants, specifically mentioning the Chernobyl and Three Mile Island accidents. In 1979, the Three Mile Island nuclear power plant in Pennsylvania experienced a partial meltdown due to a cooling system failure caused by human error. The accident resulted in the release of a small amount of radiation, but no immediate injuries or deaths occurred.
The Chernobyl disaster, which happened in 1986 in Ukraine, was a far more severe accident. The reactor became unstable during an unauthorized experiment, leading to a large release of radioactive material and subsequent fires. Many people suffered from acute radiation sickness, and long-term effects are still ongoing. Both of these accidents had significant impacts on the regulation and public perception of nuclear power.