Chapter 20

• In 1980, Sweden decided by referendum to phase out nuclear power completely by 2010
• This presented a challenge to the country, which had been trying to reduce its fossil fuel consumption since 1970, and had largely relied on nuclear power
• Developing renewable energy sources took longer than expected, so the plan to close all nuclear plants in 2010 was reversed
• In 2011, a meltdown at the Fukushima Daiichi nuclear plant in Japan spurred anti-nuclear demonstrations around the world
• In 2015, Sweden's prime minister announced plans to spend $550 million in public funding to promote wind power, solar power, hydropower, and bioenergy
• More than 80% of our energy comes from oil, coal, and natural gas, including two-thirds of our electricity
• Supplies of these are in decline, and their environmental impacts are driving us to look for alternatives
• Conventional alternatives


  Nuclear power, hydropower, and biomass energy (bioenergy) are already widely used and have less impact than fossil fuels, but more impact than "new renewable" alternatives like solar, wind, geothermal, and ocean power
• Conventional alternatives play a much bigger role in electricity generation than other forms of energy use
• Nuclear and hydropower, for example, provide about 27% of the world's electricity generation
• Nuclear power


  The use of nuclear energy to generate electricity
• The United States has the greatest nuclear electricity production, but France is the most dependent on it
• Fission nuclear energy is used to generate electricity

  1. Nuclear reactors are where thermal energy from nuclear fission is used to generate electricity

  2. The reaction that drives the release of nuclear energy inside nuclear reactors is nuclear fission, the splitting apart of atomic nuclei
• Inside nuclear reactors, control rods made of a neutron-absorbing substance (water or graphite) are inserted to keep the chain reaction under control
• If uncontrolled, the fission chain reaction can create the explosive power of a nuclear bomb
• Heat from fission is absorbed by water, which is converted to steam that spins a large metal turbine
• Nuclear energy comes from processed and enriched uranium

  1. Uranium is mined from the ground must be processed until at least 3% is uranium-235

  2. The enriched uranium is placed into metallic tubes called fuel rods
• Researchers have calculated that on coal burning facilities release about 100 times more radioactive emissions than nuclear power plants
• Drawbacks of nuclear include the disposal of radioactive waste and the potential for accidents at the plant
• Nuclear fusion forces together the small nuclei of lightweight elements under extremely high temperature and pressure
• Fusion requires temperatures of millions of degrees Celsius and so far, experiments have required more input of energy that is gained from the reaction
• Three large nuclear accidents have spawned public anxiety over nuclear power and limited its proliferation
• Three Mile Island experienced an accident due to human error and mechanical failure that led to draining of water from the reactor vessel


  This caused a meltdown, where the fuel rods melted and began releasing high amounts of radiation
• Three Mile Island was considered a near-miss, because the fuel rods did not completely meltdown, and the radiation was contained
• In 1986, an explosion at the Chernobyl power plant in Ukraine caused radioactive debris to enter the atmosphere for 10 days
• 31 people were killed directly; thousands more were sickened or developed cancer
• Atmospheric currents carried radioactive fallout from Chernobyl across much of the Northern Hemisphere, particularly Ukraine, Belarus, and parts of Russia and Europe
• In 2011, a magnitude-9.0 earthquake struck eastern Japan and sent a massive tsunami to its eastern shore


  At the Fukushima Daiichi nuclear power plant, the earthquake shut down power, and the tsunami flooded its backup generators that powered the control rods and water pumps
• Radioactivity was released during and after these events at levels about one-tenth of those from Chernobyl
• Thousands of residents of areas near the plant were evacuated and screened for radiation effects
• Another concern is that radioactive material could be stolen from plants and used in terrorist attacks
• The half-lives of the leftover radioisotopes from fission reactors is upward of hundreds of millions of years
• Currently, nuclear waste from power generation is being stored in pools of cooling ponds or thick casks of steel, lead, and concrete
• Spent fuel rods and low-level waste is currently stored in more than 120 sites across 39 states in the United States
• Nuclear waste managers would prefer, for security purposes, to store the waste in a single location that can be heavily guarded
• Sweden selected the Forsmark power plant site for its central location, and plans to store high-level waste in copper canisters buried in underground bedrock
• The United States had a similar facility planned in the Yucca Mountain in Nevada, but protests put an end to those plans in 2010
• Building plants is enormously expensive
• Plants have aged more quickly than expected, with plants shut down at only about half of their expected lifespan
• Decommissioning plants is also very expensive