Nuclear Energy

• Nuclear power is considered a conventional non-renewable method to mass produce electricity
• The nuclear power industry originated from the wartime production of nuclear weapons in the 1940s
• Nuclear power has been a consistent part of the U.S. energy infrastructure since the 1950s
• The energy derived from nuclear processes is virtually limitless
• No air pollutants are released during the fission reaction
• Nuclear technologies have applications in national defense, academic research, and medicine
• In a fission reaction, the nucleus of an atom splits, creating two new daughter nuclei and releasing energy in the form of radiation
• Only Uranium 235 (nuclear power) and Plutonium 209 (nuclear bombs) can undergo a fission reaction
• The resulting daughter nuclei are highly unstable and give off ionizing radiation that can be damaging to humans and the environment
• Nuclear power plants are designed to control the release of energy to prevent nuclear meltdowns
• The fuel source for nuclear power plants is enriched Uranium Oxide UO2
• The core of the reactor is submerged in heavy water to moderate temperatures during the fission reaction
• The heat from the fission reaction is used to heat water in a heat exchanger to generate electricity
• The steam produced is recycled back into water to be used again in the heat exchanger
• Nuclear power plants produce zero air pollution and only release warm water (thermal pollution) during normal operation
• Accidents in the nuclear industry are rare but can be catastrophic to human health and the environment
• Important nuclear accidents include Three-Mile Island, Chernobyl, and Fukushima
• Nuclear radiation mutates the DNA of living cells and is a known human carcinogen
• High-level radioactive waste from nuclear power plants needs to be stored safely for thousands of years
• Low-level waste also needs to be stored safely for long periods of time
• The current disposal method for radioactive waste is geological entombment
• Yucca Mountain in Nevada is the designated site for long-term storage of the nation's nuclear waste
• Nuclear power has advantages but also serious risks to the environment and human health
• If sustainable solutions for radioactive waste disposal are not developed, the economics of nuclear power may not be viable
• Half-life of radioactive substances:

  • Carbon-14 (14C): 5,370 years
  • Radium-226 (226Ra): 1,600 years
  • Uranium-232 (232U): 72 years
  • Uranium-235 (235U): 710,000,000 years
  • Uranium-238 (238U): 4,500,000,000 years
  • Plutonium-239 (239Pu): 24,000 years
  • Plutonium-244 (244Pu): 80,000,000,000 years
• Nuclear fission involves splitting large, radioactive atoms into smaller atoms and pieces

  • U235 and Pb207 are involved
  • Each atom decay produces neutrons, smaller nuclei, and energy
  • Strontium-90 & Cesium-137 are byproducts
• Non-military applications of nuclear power:

  • Scientific research: radiometric dating (age of earth)
  • Medicine: radiation treatment of cancer, radioactive dyes to diagnose heart disease
• Nuclear power plants basics:

  • Enriched Uranium Oxide (U235) is the fuel source (fuel rods)
  • Controlled fission reaction using control rods
  • Heat energy is converted to steam and electricity
  • Water source is needed to moderate reaction & coolant
  • Reliable energy production 24/7 with no air pollutants
  • Concerns: radioactive waste (Cesium and Strontium), potential release of ionizing radiation
• Chernobyl disaster (April 28, 1986):

  • System failure caused reactor core temperatures to rise, melting uranium fuel
• US Waste Storage:

  • Low-Level Wastes: Landfills leak, protests against building new ones
  • High-Level Waste: Short half-life products stored for a short time, long half-life products stored for a minimum of 10,000-250,000 years
• Site characteristics for high-level waste disposal:

  • Criteria: Far from population center, no groundwater, not geologically active
  • Yucca Mountain is the only site that meets all criteria