Download Comparing Nuclear Power in Virginia to Renewable Sources - Prof. John Alan Chermak and more Study notes Geology in PDF only on Docsity!
Video: “Garbage”
Nuclear Energy o Advantages Doesn’t produce greenhouse gases – very small amount compared to fossil fuels o Disadvantages Where/how to store nuclear waste In the US – we need to deal with waste from both nuclear energy and nuclear weaponry o Will we continue to store it in the short term, or find a way to store it in the long term? o Spent fuel rod (can be used for ~10 years) is radioactive for ~10,000 years o Generation of electricity – 20% Nuclear in the US o Is it safe? Chernobyl - city in Ukraine – very large release of radioactivity (nuclear accident) during the Cold War Runaway chain reaction and graphite core burned like a “giant block of radioactive charcoal” Thousands of people died because of it o 31 immediate deaths o 203 hospitalized with radiation sickness o 135,000 evacuated o Fallout in Russia, Poland, Sweden, Finland o Estimated deaths: 8,000 to 125, o Flawed reactor design, inexperienced workers, and a power surge led to… At this time, VT had a nuclear engineering program – we were having small-scale nuclear reactions – it ended after the accident 3-mile Island (1979) – was radioactivity released, against the promise of the company, the media had a field day with it The beginning of the end (in the 1980s) for nuclear power We haven’t built a new nuclear power plant since the ‘80s Mechanical and electrical malfunctions, combined with human error led to release of a small amount of radioactive xenon gas Incident caused many to question safety of power plants In the 1950s and 1960s – nuclear energy was advertised as free electricity in the US It’s actually very expensive – research funds, promises as opposed to reality Nuclear is likely to be in our future in terms of electricity because we have few other options o Nuclear energy is starting to be seen as “green energy” because of the small release of greenhouse gases How safe is it?
The Nuclear Regulatory Commission (NRC) o There is a 15-45% chance of a complete Core meltdown to happen in the US over the next 20 years o Iodide associated with nuclear reactions – goes into Thyroid, if it’s radioactive cancer Potassium Iodide can protect your Thyroid in case of a nuclear accident Why are there these risks? o Because humans are involved – we implant safety precautions, but there are good chances of accidents happening o Many western European countries are phasing out nuclear power Towards solar and wind power because they don’t want to deal with associated health issues or nuclear waste issues Nuclear power in VA o # of nuclear units: 4 (North Anna – 1-2; Surry – 1-2) o Nuclear power supplies 36.9% of the electricity generated in VA Don’t need a lot of Uranium to produce energy o 1 Uranium fuel pellet (1/2 oz.) is equal to 3 barrels of oil 1 ton of coal 1 cord of wood 12,000 cubic feet of natural gas o We don’t process nuclear waste because we don’t want to concentrate Plutonium (Plutonium can be used to make nuclear weapons) Nuclear fission o Most of the Uranium we find is 238 U we need to concentrate it to get 235 U They have the same number of protons o Bombard 235 U nuclei with neutrons o Sets off chain reaction o If chain reaction is controlled, can harness released heat to generate steam and electricity o If chain reaction is not controlled, can release huge amounts of energy Nuclear energy – security? o In 1998, almost half of the operating nuclear power plants in the US failed mock ground based terrorist security threats o In 2005, federal officials needed to monitor power plants’ methods for taking care of dangerous fuel rods US high level nuclear waste o On-site storage o Spent fuel rods sitting in water vats, generating heat not enough to turn water to steam Radioactive waste disposal o Problem: where to dispose of the various high and low level wastes generated from nuclear power and nuclear weapons o We already have more than 40,000 tons of nuclear power waste, and another 8,000 tons of defense-related waste o If we stopped producing nuclear power, there would be at least 5 truck-loads per day of nuclear waste to be transported to storage facilities (probably in Nevada – Yucca Mt.)
Worldwide distribution of reactors o The US generates more nuclear energy than any other country, but we consume so much energy that it’s relatively small in proportion o France, Britain, Sweden, and Spain are big nuclear providers; getting electricity from a lot of different places o In terms of percentage of electricity coming from nuclear power – France (75%) The future of nuclear power (US) o Many other countries have active programs in nuclear power plant construction (approx. 24 in 2005) o The US is on the up-swing in terms of building nuclear reactors Are there countries that have long-term storage facilities? o Switzerland is storing waste in a mountain – chemical processes to make sure that a spill wouldn’t spread very far o The UK We should be re-processing our waste – we would have a lot of Uranium for a long time o Doesn’t eliminate radioactivity, but concentrates it o Problem – there’s Plutonium in the re-used waste Plutonium in the wrong hands makes it very easy to make nuclear weapons Renewable o Hydroelectric Pacific NW Norway o Geothermal Plate boundaries Iceland o Solar energy Passive solar Photovoltaic Concentrating solar Cost! o Wind US, World Costs o There are huge opportunities for growth in all of the renewable energy options o Geothermal – lots of promise throughout the world, not as much in the US o Solar energy – lots of promise for growth, makes up a small percentage of our energy sources now o Wind – close to cost competitive with other energy sources (coal, etc,) o Hydroelectric – potentially cheap, but need to put up a lot of money to set it up Probably over the next 20-30 years, we will get a lot of our energy from solar power (and wind power) Hydroelectric o Need a lot of rainfall o Build big dams generate power rains generate power, etc., o Disadvantages Loss of land (it’s filled with water) O2 in the water – ?? Downstream impacts associated with the reservoir Colorado River and the Hoover Dam – downgrades the streams, etc. If you put up a dam, water flow is stagnant sediment falls to the bottom and dam starts to fill up with that sediment Impact to salmon, other organisms in the rivers o Hydroelectric – use of falling water (kinetic energy)
Worldwide, hydropower plants produce the energy equivalent of 3. billion barrels of oil per year o Dam – stores water; penstock – carries water to the turbines; generators – rotated by the turbines to generate electricity; turbines – turned by the force of the water on their blades o Hydroelectricity in the US Pacific NW – Idaho, Montana, Oregon, Washington Large percentage (80s and 90s percentages) come from hydropower in these states o Where does hydroelectric power work well? Norway – Europe’s cleanest country in terms of energy use One of the world’s largest oil exporters, yet the country has no petroleum-fueled power plants 99% of Norway’s electricity is produced from hydropower, with the remaining 1% from solar and biomass (burning wood) o Three Gorges Dam, China Will be the world’s largest hydroelectric dam and reservoir Project to be completed in the next 5 years at a cost of >$30 billion Advantages: Produce energy of 20 power plants for more than 150 million people Will reduce China’s dependence on coal Dam will help control floods Disadvantages 13 cities, 140 towns, and 1,300 villages submerged Down-gradient impacts? o Figure 14-11: Water resources
Geothermal energy o Heat and power resource that utilizes earth’s natural geothermal gradient, Fission reactions o Plate boundaries Convergent/divergent plate boundaries Potential to generate energy from hot water/magma that is very close to the surface Need active plate boundaries Northern California Iceland – a lot of hot water = geothermal; cheap energy = hydroelectric power o Where in the world are the geothermal resources? Iceland is almost entirely run on geothermal energy The western coast of the Americas; some places throughout Africa and Asia o Hot water close to the surface makes the most sense from a geothermal perspective o The temperature of the earth ~10-15 feet below the surface is ~55 degrees Can be used to cool your house in the summer or warm your house in the winter Geothermal systems, wells into the ground with water at some temperature Coils, water runs through the coils and brings it into the house and cools the house very easily or heat it easily by raising the temperature from 55 degrees Buildings around Toronto are looking at this option instead of AC Solar energy o Google – uses photovoltaic, about 30% of their budget comes from that today
Very efficient (90%) in terms of energy in; energy out o Photovoltaic cells Need a lot of land to potentially generate a lot of electricity for a lot of consumers We could put these on our roofs that are currently just roofs What are they used for? Photovoltaic (solar cell) systems convert sunlight directly into electricity Calculators have used this for a long time o This isn’t a new technology, but we have chosen not to use it Cells – Silicone with some other elements to allow the energy to transfer Actually moving electrons around In England – Hyde Park, there are boats that run at about 5 mph, completely run with photovoltaic cells Need the sun to be out, need a large amount of area Most efficient way is to use the energy immediately – we need to find an efficient way to store the energy Expensive - $25,000 installation, if we could get that money returned in ~5 years (now it’s about 10 years), more people would use them Challenges: Present design life of cells are guaranteed for 20-30 years Battery technology and storage limiting Need backup systems at night and during cloudy weather Need large amount of land to collect Costly!! o As energy gets more and more expensive, solar power gets more and more competitive o Concentrating solar system When it gets really hot during the summer time, use dark-colored materials to collect energy Focused with mirrors to create a high-intensity source (big magnifying glass) also trying to get heat energy Gaining popularity in the US south west Where are best regions to harness solar energy for electricity? Southwestern US – sunny, high temperatures, potential to produce a lot of energy Alaska – photovoltaic not a good idea, but geothermal is an option Cooling alternatives? o Solar Biggest limitation today = cost Solar-generated electricity is more costly than some of the other means Has great promise – in Germany, Denmark – providing close to 20% of energy from solar and wind power Environmental impacts How much energy does it take to make a photovoltaic cell? o Refine Silica, add other elements What chemicals do we need to make photovoltaic cells? Concern when looking at geologic footprint o If we’re not recovering the energy in terms of the amount of gas mileage saved, it doesn’t make sense Wind energy o What kind of wind is needed to generate electricity? Steady wind (not gusty wind)
Strong wind – wind speed is a critical feature, because the energy is proportional to the cube of the wind speed (if there is a little bit more wind speed, there is a whole lot more electricity generated) Proximity to people o Wind is becoming very efficient – doing better than expected in many cases in terms of how much electricity produced o Where is the wind? Top producers in the US California, Texas, Iowa, Minnesota We could work on putting windmills ~20 miles off the east coast o Environmental impacts: when the birds fly into the blades Noise, visual impacts Bats – we don’t know much about migration patterns/where we can put up windmills o GBSU, Ohio Four wind turbines are located at the Wood County landfill on US Route 6 (first utility-scale landfill in Ohio) Turbines are 131 feet long, weight 15,000 lbs – by January 2004, the two turbines has produced enough electricity to power 1,254 homes (nearly 2x the original expectation) o Does the US lead in wind-generated electricity? Until 1998, wind generating capacity in the US remained flat The rest of the world, especially Europe has really taken off in terms of wind power Early 1980s – today; wind is close to, if not cheaper than many of the other ways to generate electricity Most of the wind energy produced in the world is in Europe Top 5 markets for new wind capacity in 1999 o Germany, US, Denmark, Spain, China o Wind generated electricity and technology Rocky Flats Prototype Examples Flexible, hinged blades Turbine 40% lighter Rotating gear box All have helped in lower the price per kilowatt to produce electricity “Future” renewable energy sources but they all take money to develop o Fusion – probably has most potential – instead of taking elements apart, combining them o Cold fusion? o Tidal energy o Thermal conversion in Oceans o Wave energy o Hydrogen (not renewable) Harnessing fusion o Method: Plasma and magnetic field 1 million, 1 billion degrees Celsius Waste and recycling, Ch 22 o Municipal solid waste (MSW) is the “garbage” that is generated o We could landfill, incinerate, or recycle We should try to reuse as much of our waste as we can o Each year in the US over 5,000 million tons of waste is generated 75% from mining and oil and gas production Agriculture – 13%
