containment buildings and released radioactive gases — including cesium 137, the principal radioactive isotope released by the Chernobyl accident — from the damaged fuel. To prevent such a power loss in the future, plant operators should install multiple connections to the offsite power grid; station emergency diesel generators on high ground; and deploy plenty of mobile emergency diesel generators [1] . Third, power plants location. After the nuclear accident, Fukushima Prefecture carried out a thyroid examination for approximately 380,000 children in the prefecture. As of February 2018, 159 people had been diagnosed with cancer, and 34 people were suspected of having cancer. I think the site selection is as important as the other measures. It is a comprehensive balancing process that takes into account factors such as safety, environment, technology and economy. Due to the importance of nuclear safety, the safety requirements for the location of nuclear power plants are very strict. The location of nuclear power plants should consider the effects of various extreme external events in the site, including earthquakes, geology, meteorology, floods, and aircraft crashes and chemical explosions; consider the impact of nuclear power plants on the surrounding environment, including drinking water. , planting and aquaculture, and ecological protection areas, etc., to ensure that the impact of the nuclear power plant on the public and the environment under normal operating conditions and accident conditions is within the limits set by the state. 3. Both nuclear fission and fusion are discussed in the presentation. Based on the discussion, please write your understanding of the future of both technologies. As far as I am concerned, I think people should focus on fusion technology. The main reason is that nuclear fusion could generate much more power than the nuclear fission. As we all know that nuclear fusion happens in Sun so it means if we control the nuclear fusion technology, the energy crisis will no longer be a problem. Nuclear fission power generation can reduce air pollution caused by coal-fired power generation, slow down greenhouse effect and reduce transportation costs. However, since 2011 Fukushima nuclear power plant accident, the danger of fission technology has been shown to the public. Many nuclear power plants have been shut down around world. I predict that the nuclear fission will be replaced by nuclear fusion. Firstly, nuclear fission produces large amounts of radioactive contaminants. These radioactive materials released by nuclear reactions can have serious side effects on the natural environment and life safety over time. The location of nuclear power plants, often away from urban areas, is to minimize the impact of nuclear radiation on people. No matter how much effort is made, people can't completely eliminate