Carla's+notes-Nuclear+power

Carla’s notes-Nuclear power: Book: Nuclear power of the future: New ways of turning atoms into energy =Bibliography= Giacobello, John. __Nuclear power of the future: New ways of turning atoms into energy__. New York: The Rosen Publishing Group, 2003.

//Radiation//. (n.d.). Retrieved April 12, 2010, from Wikipedia: http://en.wikipedia.org/wiki/Radiation

Wasserman, H., Murray, I., Wood, G., Freed, J., J. Dudziak, D., & Alverez, R. (2010). //Nuclear power.// (L. S. Friedman, Ed.) Christine Nasso.

__Guiding question:__ Is nuclear energy a safe energy? ie. weapons, accidents, radio activity.

__Questions:__ 1. What does it mean when something is radioactive? 2. Is nuclear power contained? If so, can you contaminate it? If it gets out will it blow up? 3. How does radioactivity affect you? 4. Why do they have to dispose of radio rods? 5. What is Uranium?

General notes: · Make weapons used at end of World War 2 when United States bombed Japanese cities of Hiroshima and Nagasaki 1945. · Fear heightened by movies, T.V, media (false or exaggerated reports) · __Uranium:__ Radioactive, is the source of nuclear power. Dense metal found in 1789. · Named after the planet Uranus.

__How Nuclear power plants work:__ · Nuclear energy is created when Uranium is split. · Isotope: Same electrons, different number of protons. · Example: U-235 (Uranium-235 protons+neutrons). Contains 92 protons and 143 neutrons. If you add 1 more neutron with enough force, then the atom can split in two. Then releases energy in the form of heat. Often neutrons come out and hit other nuclei. Causes same reaction of split and this chain reaction is called __ Nuclear Fission .__ This is what makes nuclear power possible. The hear release is what we use to produce electricity. · This process takes place in a nuclear reactor. Has a core that stores Uranium. Uranium pellets are put into fuel rods, then rods insert into core. Fuel rods are 3.5 meters (11.48 feet) long, 1 centimeter in diameter. · Fission occurs when enough fuel rods are bundled together in core. Amount of Uranium it takes to start the process is called “critical mass”. · Critical mass cannot generate nuclear power. If neutrons in core move to quickly, other Uranium atoms cannot absorb them. Prevents Fission from occurring. So core uses moderator to slow down neutrons. Water (most commonly used moderator) slows down neutrons enough so they can be absorbed by other Uranium atoms. The result is heat. · Fission that is out of control can explode. To prevent this control rods are inserted in core (metal). They slow or stop the chain reaction by absorbing neutrons. Technicians use this method to controls the level of energy, much like controlling volume on a stereo. · Next stop to making electricity from nuclear power is to make __steam__. · Water travels through a pump into core reactor. Process of fission heats up the water. Core is under high pressure, water cannot boil away. Water absorbs heat, then get’s pumped into part of reactor called the __heat exchanger__. · Heat exchanger takes hot water and uses it to heat other water. They do this because the coolant water (water used to heat other water) has become radioactive from fission process. The coolant water can now kill animals. · Small amounts of radioactivity exist in nature, but high activity is dangerous. · To prevent radio waves coolant is put into a shielded area. · Steam is energy that is sued to turn a turbine. · Shaft inside turbine that is wrapped in copper. Steam spins shaft, wires move past magnets inside turbine. As wires move through magnetic fields, becomes electrically charged. Charge travels along wire leading out of turbine to other wire that sends it out to homes, offices, and factories as electricity. · This reactor is called a __pressurized water reactor__. Another reactor is a __Heavy water reactor__. It uses “heavy water” which means it is made up of 2 atoms of deuterium (non radioactive isotope of hydrogen) and one of oxygen. This is used because Uranium in water does not have to be enriched so the fuel is cheaper.

__Uranium:__ · Lot’s of uranium in earth, but we usually use oil and coal. · Not all uranium is radioactive, only about .7% is in U-235, the isotope needed for fission. Most uranium is U-238. To get it to 235, the uranium must go through a process called enrichment. · Get formed into pellets that get inserted into fuel rods. · Disposing of nuclear waste properly is one of the biggest challenges for nuclear power industries. · Uranium produces is own energy.

__History:__ · Atomic energy was under strict control by the U.S gov. 1940’s. · Nuclear power then was only used for war. · By 1950’s gov. shows experimental reactors to possible investors for companies with __Price-Anderson Act__. This law set a limit for how much a company would have to pay in this event of an accident. · 1964, private ownership of special __Nuclear war Materials Act__ became law, making it possible for utilities to purchase and awn enriched uranium. They could now use u-235 in their power plants. Big step in ending the “monopoly” or game the gov. had held over nuclear materials. Helped private nuclear industry to expand. · 1974, __Energy Reorganization Act__ was passed. It split the AEC into two separate commissions. The Nuclear Regulatory Commission (NRC) would watch and make sure the nuclear power industry was safe. All nuclear companies had to report to NRC. Energy Research and Development Administration oversaw the nuclear weapons program. · __Low-level waste Act__ 1980: Goal, to spread out the burden of low-level waste disposal as evenly as possible across the U.S. · 1987, Yucca Mountain is the best place to put a power plant because it is far away from people, and it is extremely dry so no other water can be contaminated. · Nuclear power plants have gone into a slump because of so many accidents (ex. Three Mile Island or Chernobyl) Even though they say they are cheap, and renewable recourses people are afraid of the danger. Another problem is decrease in gov. funding since 1970’s. Keeping reactors safe costs a lot of money. Recourses shrinking (oil, coal, natural gases). · Estimated that by 2020, U.S energy consumption will have increase by 20%, so to keep up with growth we will need to build over 200 nuclear plants.

__Nuclear plants:__ · Nuclear power plants do not produce carbon dioxide, so they do not produce green house gases for global warming. · Nuclear power today keeps as much green house gases out of the atmosphere as taking 94 million cars off the road. · Fossil fuels also emit other toxins that can damage our health and environment. Properly maintained nuclear reactors give off small amounts of emissions. · Nuclear industry only energy industry that is fully responsible for disposing it’s own waste. · Debate on whether they can build enough nuclear reactors to make a difference towards global warming. Nuclear power plants are expensive. It would mean replacing coal-fire power plants, costing trillions. Also take decades to achieve. · Fossil fuels eventually run out. Uranium, one of our most abundant energy sources. Need a lot less uranium then fossil fuel to produce the same amount of energy. We can process Uranium and use it again. · Uranium in old nuclear powered weapons can be used to generate power, important ideas to consider in the future. · Cost: no longer gov. money to help power companies. Adding safety and storing waste has made it more costly. Average production cost for generating power 1.92 cents per kilowatt-hour, compared to 1.88 cents for coal-fired electricity, 2.68 cents for natural gas, and 3.77 cents for oil. But the average cost does not include rising cost of updating reactors, maintaining them, or storing them. · “A 1986 study of seventy-five U.S reactors compared their original estimate construction cost with their final costs. The study found that the original estimates for constructing seventy-five reactors had been $45 billion. The final costs totaled $145 billion! //Forbes// magazine called the U.S nuclear power program’s economic handling “the largest managerial disaster in business history”. Still, some people say that new and more efficient designs of reactors would work more efficiently and be safer to run. The total costs would then be much less.” · Terrorists try to steal nuclear materials for bombs. Few have knowledge or ability to use such materials. Even the simplest bomb can cause catastrophe, spreading radioactive materials everywhere. · Nuclear Regulatory Commission does not require power plants to defend against terrorist attacks. Lack of defense makes it vulnerable against attacks. · Humans have caused all nuclear accidents. No way to completely prevent accidents, can only take precautions. · “Do we risk a potentially fatal nuclear accident, or do we risk destruction by pollution from fossil fuels and global warming?” 

__Radiation:__ · When energy travels through an object. · “Some types of radiation have enough energy to [|ionize] particles. Generally, this involves an electron being 'knocked out' of an [|atom] 's electron shells, which will give it a (positive) charge. This is often disruptive in biological systems, and can cause [|mutations] and [|cancer] .” · Ionize: to separate a atom into positive an negative. To make it an ion. · __Alpha radiation__ : (a) method of decay in large nuclei. Alpha particle (helium nucleus, He2+), has 2 neutrons and protons. Relatively high charge, it is heavily ionizing and will cause sever damage. Due to high mass, it has little energy and low range. Typically, a sheet of paper or skin can stop it. · __Beta (+/-) radiation__ : (B)consists of an energetic electron. Less ionizing than alpha, but more than gamma. Often can be stopped by a few centimeters of metal. Occurs when neutron decays into proton in nucleus, releasing beta particle. · __Gamma radiation__ : (Y) Consists of photons with a frequency greater than 10(to the power of 19). Occurs to rid decaying nucleus of excess energy after it has emitted either alpha or beta radiation.

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__Nuclear waste:__ · Nuclear power plants produce a lot of waste, often stored on site because no other safe place to put it. · We might be able to recycle the used fuel. Uranium and Plutonium elements used to make nuclear power might be able to be extracted from the used rods and used to make new fuel. This method will help preserve uranium. · If a nuclear waste facility was opened, it can provide more jobs. · World wide, number of nuclear power plants expected to double, with at least 1,000 operating by mid-century. But there might not be enough uranium to go around. · Fast fact: “ The Global Nuclear Energy Partnership states that recycling nuclear waste into fuel for a new generation of reactors would produce one hundred tie more energy than conventional reactors and generate 40 percent less waste.”

__Health risks:__ · Power plants emit radiation, and can cause huge accidents. · People in the areas of Chernobyl and Three Mile Island experienced high rates of cancer, hair loss, bleeding sore, and asthma. · “Either by error, or by terror” · Deaths from Chernobyl were estimated to be 300,000. Infant death and childhood cancer rates in down wind areas have been horrific. · “ Even though Chernobyl occurred more than twenty years ago, people are still suffering and dying from its effects. · Fast fact: “ An April 2006 report by the European Greens for the European Parliament estimated there will ultimately be between 30,000 to 60,000 fatal cancer deaths as a result of the 1986 Chernobyl nuclear power plant accident.” · Farmers à death toll of animals horrendous · “The multiple killing powers of radiation remain as much a medical mystery as how much fallout escaped in each case and where it went” · Chernobyl: $900 million to build, but than $2 billion to clean up. The cost of the accident in lost power, damaged earth, medical needs, communities without power have equaled to half-trillion dollars and still climbing. · All people are exposed to low levels or radiation every day. From environment and man made things. · Chernobyl killed just 56 people and made 20 square miles of land uninhabitable. · Chernobyl was caused by features unique to the Soviet-style. When reactors of that sort get to hot, rate of nuclear reaction increases. The reverse of what happens in most. · No level or radiation is safe · Fuel rods need to be replaced every 18 months. · In radioactivity: When materials decay, they become less dangerous. · Question is what to do with the waste once space runs out. · They are able to reuse the uranium and plutonium, so only a little bit of radioactive waste remains. · British gov. has determined that “geological disposal”-burial deep underground- provides the best available approach to dealing with existing and also with new nuclear waste.