For a concise primer on energy use in the United States and for the world in terms of rates of use (2005) and fuel sources click: World-USA total energyg
Utility –Annual Amount —Annual lbs CO2*
Electric –1,781,706 kW-hrs— 2,000,000
Gas Heat– 175,889 therms— 2,057,901
Oil#2 Heat– 35,000 gallons— 780,150
Gasoline– 203,480 gallons—4,069,608**
TOTAL= 8,907,659 lbs of CO2 emissions/year **only for student commuting to school
WA’s Fossil Fuel Heating System
Up until the 1970’s WA heated its campus by burning coal in a 1940 model boiler (middle photo above) located underneath the Megaron. Water was boiled into steam and pumped through large pipes (top right) throughout all of campus. This centralized heating system lost vast amounts of heat energy during transfer through contact with the cold earth, and by burning coal, the dirtiest of the three major fossil fuels, emitted carbon dioxide, sulfur dioxide, carcinogenic hydrocarbons and particulate matter, mercury, and arsenic.
WA used the same boiler when it switched over to heating oil #6, a thick high sulfur content fuel.
At some point in the 1990’s WA began decentralizing its heating system, placing gas boilers (below middle) in each building. Cleaner less polluting natural gas is burned to heat up water which is then pumped (photo of motors, below right) in pipes throughout the building in the form of hot water rather than steam. In 2003, WA installed oil #2 (lower sulfur content) boilers (below left) to replace the old Megaron boiler, the only campus system burning oil.
Student’s communting to school demands the largest amount of energy. As a country the USA uses nearly 21 million barrels of oil each day, 40% of which is processed to make gasoline for passenger vehicles alone. The US imports over 60% due to domestic reserve levels that by themselves would sustain this daily rate for less than 3 years.
WA ’s Electricity Use – Regional Top 5 Electricity Sources
1. Natural Gas (35%)
2. Nuclear Fission (27%)
3. Coal (16%)
4. Hydropower (6%)
5. Oil (4%)
We use electricity that is transmitted through an integrated New England power grid and not from any particular power plant. That means we use whatever electricity is flowing through out local grid while we pay specific power plants to generate the amount of the power we use by the above percentages and whose actual electricity may be consumed by the nearest city, town, residence, etc. From a deregulated market our power supplier is Direct Energy, who is responsible for the generation and/or purchasing of power from any one plant, while our power delivery is managed by National Grid.
The Nuclear Option
Worcester Academy gets approximately 27% – as compared to a 20% national average- of its electricity from nuclear energy: fission of 2-3% enriched Uranium-235.
The benefits of nuclear are the enormous amount of energy that fissionable U-235 releases. One gram of U-235 (depending on enrichment level) produce the same amount of heat energy as burning 6,000 pounds of coal when used to heat water into steam which in turn spins a turbine to generate electricity. Further, there are no greenhouse gas emissions, electricity can be produced cheaply (though this could be argued against given special insurance policies for nuclear and unsettled costs for nuclear waste management), and in theory nuclear fuel can be reprocessed many times over. Capacity of New England nuclear reactor plants (see photo) is as follows:
Location- Name- Capacity
Maine- Wiscasett Maine Yankee (closed) 850 MW
CT- Haddam Neck Plant (closed) 590 MW
Millstone Nuclear Niantic Bay, Waterford (unit
closed) 652 MW
Unit 2 900MW
Unit 3 1200 MW
VT- Vermont Yankee, Vernon, VT 540 MW
NH- Seabrook Nuclear Station, Seabrook, NH 1200 MW*
MA- Yankee Nuclear, Rowe, MA (closed) 185 MW*
Plymouth Station, Plymouth, MA 655MW
Approximate Total: 4,500 MW (operating)
However, reprocessing fuel is dangerous (particularly if spent plutonium is involved, which can be isolated easily using chemical means to make a bomb but is rare in the US for energy production) and there are currently no operating reprocessing plants in the United States. Complications with nuclear energy also include managing nuclear waste which contains lethal and carcinogenic radioactive materials with half lives ranging from a few dats to 10’s of 1,000’s of years [Pu-239:1/2 life=24,360 years: alpha emissions, cocentrates in bones/lungs, Sr-90: 1/2 life= 28.8 years: beta emissions: concentrates in bone and teeth, I-131: 1/2 life=8days: beta and gamma: thyroid, Cs-137:1/2life=30 years: beta and gamma: whole body] The many waste products of nuclear fission, such as these, must be handled without mistake and need to be stored securely for 100,000’s of years. Current solutions have included underground storage in geological stable caves. Currently there are over 50,000 metric tons of nuclear waste in the U.S., ( click for details: us-nuclear-waste.pdf ) most of which is stored in water pools on-site of the power plants (see Yankee Rowe photo). Over 3,000 tons of waste is stored in New England Power Nuclear Power Plants (see photos).
Some point out the security issues of transporting the waste through highway, water, and railway to waste collection sites such as the proposed Yucca Mountain, Nevada. Studies have also shown and critics point out ways that nuclear plants are not secure from terrorist attacks.
For further explanation and more information on nuclear science click on MITcourse nuclear info.jpg
Many scientists studying energy supply and climate change remediation insist that nuclear power needs to be part of the solution.
Essential questions:
1) How many nuclear power plants would need to be built to meet increasing world energy demands and after the end of oil?
2. What is the risk analysis for nuclear fuel procurement and waste production management, transportation, as well as attacks on nuclear facilities? What are the realities and complexities of storing nuclear waste?
3. What is the economic structure and conditions for past, current, and future nuclear power plants?
4. What are the numbers for the world’s current nuclear fuel sources? What will they be in the future?
5. What impact does uranium mining and reprocessing have on the environment, workers, etc.?
6. What % of efficiency as a resource unto itself would be needed to replace the use of nuclear, how could this number be achieved?
* It is important to note that CO2 reductions are approximated values. For commuting, 20mpg was used 20lbsCO2/gallon used. Both numbers would more exact if every trip was measured for gasoline used/distance driven or even actual CO2 out of the tailpipe as driving habits, car model-year, maintenance habits, gasoline type used, etc. can effect CO2 emissions. For powerplants and fuels the same logic applies: powerplant efficiencies and CO2 emissions fluctuate based on year made, type of coal, etc., model, filtering technologies, peak demand production, and a changing % purchase of nuclear versus gas versus coal, etc. It is a moving target but levels given are reasonable estimations. WA fuel burning, since on site, poise similar issues.
May 17, 2008 at 11:54 pm
At Worcester Academy, we use multiple energy sources including electricity, gas, and oil. Combined, all of this fossil fuel use produces 8,907,659 lbs. of carbon dioxide every year. The heating system on campus was centralized, using a 1940 model boiler that burned coal under the Megaron. It lost enormous amounts of energy during heat transfer and released carbon dioxide, sulfur dioxide, carcinogenic gases, mercury, and arsenic into the environment. Now we have a decentralized system that is much more efficient
Nuclear power is more efficient because it doesn’t produce direct pollution. However, we must find a way to dispose of nuclear waste and there isn’t an efficient way f doing that yet. Nuclear power is cost efficient. There are 434 nuclear power plants in the world. Hydroelectric power is capturing energy from the moving water. It uses fallen water and converts it into mechanical energy. Mechanical energy gets turned into electrical energy. There is no waste for hydroelectric power. Dams store water so they can control how much energy is produced efficiently.
May 18, 2008 at 1:58 am
In our society, we use fossil fuels more than we need to. We use fossil fuels for heat, electricity, and transportation. Fossil fuels are a limited resource and have a negative impact on the environment. Fossil fuels have a negative impact on the environment including air and water pollution. They release harmful gases into the atmosphere that overall damage the environment.
In order to make energy more resourceful, we could use alternative sources such as solar energy, wind turbines, and water turbines. In order to use solar energy, we capture energy from the sun. Solar panels use mirrors and reflectivity to capture the sunlight and convert it into electricity. Another way to use solar energy is solar ovens that cook food and sterilize water. By using wind turbines, we can harness the winds energy into turbines and convert it into electricity. Wind turbines take kinetic energy from the wind and convert it into mechanical energy. Likewise, we use the force of water in water turbines to convert its energy into electricity. An example of some of these types of renewable energy is hydropower is the renovation of the Whitin Mill. They will put in a new water turbine where the original one was so the Mumford River can power it once again. This will cost roughly 1.8 million dollars but in a year it will pay for itself. The Whitin Mill also has 32 solar panels on its roof.
February 11, 2009 at 2:18 am
1) How many nuclear power plants would need to be built to meet increasing world energy demands and after the end of oil?
“My projections simply envisioned nuclear energy growing from supplying 6% of world energy needs today to one third of the energy demand in 2050, which was taken to grow by about a factor of 3 from 2000. But, of course, that begs the question: Can fossil fuels continue to provide energy at or slightly above present levels, to produce about one third of the energy demand in 2050? And is it likely that hydro, wind energy, and other alternatives can provide the other third, which is also the equivalent of 100% of today’s total energy use?
So, nuclear power in 2050 would be roughly 18 times its current use. This requires fewer than the number of plants I projected in 1997, and is equivalent to about 5,100 1,000-megawatt-electric (MWe) plants.”
“A plan for rapid growth to a level long-term production capacity to support long-term energy growth and replacement of old plants and fossil fuels, would result in producing roughly 200 new units per year. We can plan for 6,000 equivalent units, taking our present operating plant capacity as about 300 1,000-MWe equivalent units (from about 440 actual units).”(1)
4. What are the numbers for the world’s current nuclear fuel sources? What will they be in the future?
“A nuclear power station of 1000 megawatt electrical generation capacity (1000 MWe or 1 gigawatt electrical = 1GWe) requires around 200 tonnes (metric tons) of uranium per annum. For example, the United States has 103 operating reactors with an average generation capacity of 950 MWe expected to consume over 22,000 tonnes of uranium in 2005.
Uranium production is subject to the same “Hubbert” cycle which characterised US oil production, which peaked in 1970. In spite of improved extraction technology it has declined since then, so in that in 2005 around 65% of US oil demand will be imported. An individual uranium mine provides a rapid build-up followed by uniform production over 5 –10 years after which it declines and is closed. To maintain supply a series of mines have to be opened in succession. The aggregate of the individual mine supply curves produces a world “Hubbert” peak in uranium production which will eventually limit the level of “once-through” nuclear power generation, whereby spent fuel is not re-cycled.
This limit was recognised from the inception of nuclear power resulting in several abortive attempts to develop fast breeder reactors and waste recycling processes. In December 2002 ten nations produced “A Technology Roadmap for Generation IV Nuclear Energy Systems” which concluded that to extend the nuclear fuel supply into future centuries it will be necessary to recycle used fuel and convert depleted uranium rejected from the enrichment process to new fuel. Six types of fast reactor were considered, each requiring US$ 1 billion to take to a demonstration phase in 2025. The authors found it impossible to choose between the six options and recommended “crosscutting R&D” between rival participants.
MIT’s study “The future of nuclear power” opted for the “once-through” mode in which discharged spent fuel is sent directly to disposal. The team believe that “the world-wide supply of uranium ore is sufficient to fuel the deployment of 1000 reactors over the next half-century”. In an appendix (5.E) they argue that the extraction of low concentrations of uranium in phosphate deposits will suffice for a programme ending with a “1500 GWe scenario” by mid-century.”(2)
5. What impact does uranium mining and reprocessing have on the environment, workers, etc.?
” # Nuclear energy is not clean. All parts of the nuclear fuel cycle, from uranium mining to reprocessing, contribute to the creation of long-lived radioactive wastes.
# Nuclear energy is not cheap. In many places renewable energy sources are as cheap or significantly cheaper than nuclear energy. When the electricity utilities were privatised in the United Kingdom the market refused to purchase or support nuclear utilities.
# Nuclear energy is not the answer to global warming. Extensive studies have shown that each dollar invested in end-use energy efficiency displaces nearly seven times more carbon than a dollar invested in nuclear power.
# Nuclear power is not safe. Nuclear reactors routinely release radiation into the surrounding environment. Incidents, accidents, releases and leaks plague the industry in every country where it operates.
# Uranium mining is not safe. According to the International Physicians for the Prevention of Nuclear War, uranium mining has been responsible for the largest collective exposure of radiation to workers. One estimate puts the number of workers that have died of lung cancer and silicosis due to mining and milling alone at 20,000. It is widely agreed that there is no safe level of radiation exposure.
# The threat posed by nuclear weapons is not over. More than 40,000 nuclear warheads still exist. Nuclear proliferation continues and there is a growing global trade in smuggled nuclear materials.
# The problems of nuclear waste have not been solved. Despite industry assurances, nuclear waste remains a very real and very potent danger. It needs to be isolated from people and the wider environment for up to tens or even hundreds of thousands of years.” (3)
(1) http://www.larouchepub.com/other/2005/3225build_6000_nukes.html
(2)http://www.hubbertpeak.com/nuclear/WhyNuclearNotSustainable.htm
(3)http://www.sea-us.org.au/acfuconf97.html