Alternative Energy Mix in Texas
nuclear energy
"Nuclear is a crucial part of the nation's energy mix because it's clean, efficient power."
- Angela McCalpin, Civil Engineer, Bechtel
Nuclear energy is the production of energy from uranium atoms being split in a process called nuclear fission. This produces large amounts of heat which are then used to convert water into steam. This steam is used to turn turbines and generate electricity. This process of electricity generation does not produce any carbon dioxide emissions. In this way, nuclear energy is similar to many of the renewable energies, but it does not suffer from the same issues of intermittency.
Nuclear energy is able to run at all times, which makes it more suitable to be one of the foundational energy sources that is constantly supplying power to the electricity grid. However, this important benefit is also one of the drawbacks of nuclear energy. Nuclear energy runs at about the same amount of efficiency at all times; it cannot increase or decrease energy output in line with demand in the same way that can be done with coal and natural gas (1).
There is a finite amount of uranium in the world, so nuclear energy isn't considered to be a renewable energy source. It has instead been deemed a "sustainable" source of energy. There's predicted to be around 100 years worth of uranium (2). It’s classification as a sustainable source of energy as opposed to a renewable source has prevented it from being able to benefit from many of the government subsidies that other low-emissions of energy as opposed to a renewable source has prevented it from being able to benefit from many of the government subsidies that other low-emissions fuels have received.
Though the production of nuclear energy does not emit carbon dioxide, mining uranium, the construction of nuclear power plants, and the storage of nuclear waste all pose environmental issues. Many of the additional safety features that are now included in the construction of new nuclear power plants involve the use of concrete and steel. One of the components of concrete is cement, and the production of both cement and steel both results in large amounts of carbon dioxide emissions. Below are calculations for the CO2 emissions that occur from the production of the steel and concrete that are used in the construction of an average power plant [the estimations for the amount of concrete and steel required in the average power plant are from source (10)].
Currently, around one-third of the electricity in Texas is generated through nuclear power. This power is generated by two nuclear power plants in Texas, the South Texas Project and the Comanche Peak Nuclear Power Project. There had initially been plans to build 5 more plants in Texas. However, some of these plants have been delayed as a result of the 2011 nuclear disasters in Japan. Should these plants be completed, they would provide enough energy for 6.8 million homes a year (4).
A large obstacle that nuclear energy has faced in its attempt to grow is the inability of the public (and thus investors) to forget the aftermath of the failures of nuclear power plants. These failures are typically marked by hundreds of deaths and hazardous levels of radiation being emitted into the atmosphere in the area surrounding the plant. Though these accidents are few and far between, their sheer magnitude is enough to send investors running. After the nuclear disaster in Fukushima, Japan, both Germany and Japan decided to scale back the amount of energy they got from nuclear. In fact, Japan pulled each of its 48 reactors offline, and between the two companies 15 reactors exited service completely (5). Similarly, Switzerland put some of its plans to build nuclear reactors on hold. Incidents like this put a damper on nuclear energy’s ability to grow.
Comanche Peak Power Plant
Source: Luminant
From 1950 to 2010, though nuclear energy and renewables both received the same percentage of federal incentives, most of those for nuclear energy were devoted to research and development. None of its incentives were related to tax policy or market activity (3). Both renewables and nuclear energy received a fairly small amount of federal incentives in comparison to oil and gas, which together have received nearly of all the incentives provided during the 60 year time period. Thus, the fate of nuclear energy is far largely determined by changes in the market. This is especially true in Texas where the electricity grid has been deregulated, meaning that the government no longer has a say on the price of natural gas or any of the other energy sources. Lately, nuclear energy has been struggling as the price of natural gas continues to fall. Without the advantage of lower price, many investors are beginning to choose natural gas over nuclear more frequently. In 2015, the amount of operating nuclear power plants fell to below 100 (1).
The graph below shows the percentage of the US fuel share that nuclear energy has taken up from 1971 to 2014. The years in which the percentage decreased are highlighted in red. Within the years that have decreases, the most expensive major nuclear incidents (defined as events with over $1 million in damages) that occured within the US in that time period are shown (with a notable exception being Fukushima, which was included due to the large effect it had on the nuclear industry in the US.) Each year with a decrease in the percentage has a major nuclear incident either within the same year or in the year before. To the left, each of the events shown on the chart, minus Fukushima, will be listed, along with the amount of damages that were incurred.
1979 Three Mile Island (Middletown, Pennsylvania); $2.4 billion
-
Notably, the only US nuclear incident to have an INES rating
1989 Lusby, Maryland; $120 million
1993 Bay City, Texas; $3 million
1996 Crystal River, Florida; $384 million
2002 Oak Harbor, Ohio; $605 million
2005 Braidwood, Illinois; $41 million
2010 Vernon, Vermont; $700 million
Nuclear Energy's Percentage of US Fuel Share
Created by Sydnee Landry
Using data from nei.org (6) and source (7), (8), and (9)
Similarly, the storage facilities that contain used nuclear fuel are steel-lined, concrete pools inside of concrete and steel containers (12). Nuclear waste is radioactive and is thus hazardous to human health and it must be stored very carefully to ensure that no radiation is emitted. These concrete pools are typically where the used fuel is stored temporarily near the site of its use for a period of at least five years. The fuel was intended to be stored in the pools for a decade or two at most, but much of the fuel in the pools has stayed in for much longer than was initially anticipated. This has led to a shortage in fuel pool space, and as a result the used fuel is now having to be stored in aboveground steel and concrete containers (13). The Yucca Mountain repository was proposed in 1987 as a solution to the long term nuclear waste storage issue in America. However, there the project has experienced many delays and was even cancelled in 2009 under the Obama administration. The DOE’s movement to withdraw its license to construct and operate the repository was denied, and in 2013 the federal appeals court ruled that the DOE’s license to construct and operate should be reconsidered and reviewed (14). There is currently no other long term nuclear waste solution that has been implemented in the United States. Research is being done on the possibility of recycling used nuclear fuel, but the technology is nowhere near ready for commercial use in the US.
Most nuclear energy power plants take around 9 years to complete. The process of constructing a nuclear power plant requires a lot of initial financial input. On average, the construction costs of building a large nuclear reactor can be from $6 billion to $8 billion (2). However, there are methods and policies being introduced that attempt to help mitigate some of these high initial financing costs. The Construction Work in Progress (CWIP) method was created as a way to help utility companies finance construction costs while avoiding high interest costs. This method involves charging customers a small additional monthly charge as the plant is being built, as opposed to paying over the entire life of the plant. This leads to a quicker recovery of the financing costs that were incurred during construction and avoidance of further interest costs, so the overall cost to finance the project is lower for both the utility companies and customers (2). In the state of South Carolina a nuclear power plant implemented such a plan and it’s projected to save $1 billion in capitalized interest costs (15). In 2005 the Energy Policy Act was passed, and it provides some investment stimulus for the construction of new power plants.
Nonetheless, high capital costs, long term waste storage issues, and fluctuating investment in the face of nuclear meltdowns have left the future of nuclear energy in Texas uncertain. It most likely won't grow at a pace fast enough for it to be the transitional source of electricity that natural gas is proving to be.
CONCRETE
The average new power plant requires approximately 400,000 cubic yards of concrete. Concrete is around 10 to 15% cement, and the production of 1000 kg of cement emits on average between 900 and 1100 kg of carbon dioxide (11). The calculations will use the midpoint of these ranges, i.e. assume the concrete is 12.5% cement and assume that 1000 kg of carbon dioxide will be emitted.
400,000 cu yd x (1,839.92 kg concrete)/(1 cu yd) x (0.125 kg cement)/(1 kg concrete) x (1000 kg carbon)/(1000 kg cement)
=91,996,000 kg carbon
STEEL
The average new power plant requires approximately 66,000 tons of steel. One ton of steel produces about 2 tons of carbon dioxide.
(66,000 tons steel)/1 x (2 tons carbon)/(1 ton steel) x (907.185 kg carbon)/(1 ton carbon)
=119,748,420 kg carbon
TOTAL
91,996,000 + 119,748,420
=211,744,420 kg carbon, which is rougly the same as burning 23,768,662 gallons of gasoline*
SOURCES & NOTES
1. http://oilprice.com/Alternative-Energy/Nuclear-Power/Natural-Gas-Threatens-U.S.-Nuclear-Future.html
2. http://www.nei.org/Knowledge-Center/FAQ-About-Nuclear-Energy
3. http://www.nei.org/Issues-Policy/Economics/Incentives-for-Energy-Production
4. https://stateimpact.npr.org/texas/tag/nuclear-energy-in-texas/
5. http://edition.cnn.com/2014/03/12/business/nuclear-power-after-fukushima/
7. http://www.theguardian.com/news/datablog/2011/mar/14/nuclear-power-plant-accidents-list-rank
8. http://fcir.org/2011/11/16/planning-meltdown-results-in-2-5-billion-nuclear-mistake/
9. Benjamin K. Sovacool (2009). The Accidental Century - Prominent Energy Accidents in the Last 100 Years
11. http://www.nrmca.org/sustainability/CONCRETE%20CO2%20FACT%20SHEET%20FEB%202012.pdf
13. http://www.nei.org/Issues-Policy/Nuclear-Waste-Management/Used-Nuclear-Fuel-Storage
15. http://www.nei.org/CorporateSite/media/filefolder/CWIP.pdf?ext=.pdf
16. http://www.eia.gov/tools/faqs/faq.cfm?id=307&t=11
*Calculated using EIA's finding that one gallon of gasoline emits roughly 19.64 pounds of CO2 when burned (16)