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Forty years since Three Mile Island became the site of the United States’ worst nuclear power accident, the Pennsylvania plant has shuttered. Advanced technology and investment in renewable energy has changed the game for electric companies, but the meltdown’s residual power lives on.
Three Mile Island operated two pressurized water reactors, but on March 28, 1979, a malfunction in the cooling circuit of the second unit caused the core to be exposed and overheat. Miscommunication within the plant staff, government officials and the media led to panic, but the leak of radioactive gases was minimal. Studies in the decades since have shown no health consequences from the incident, yet increased regulations have been widespread.
Closer to home, Carolina Power & Light and the N.C. Eastern Municipal Power Agency set out to build Harris Nuclear Plant 70 miles from Wilson in New Hill. Construction began in 1978, but Three Mile Island threw a wrench in the plans and increased the costs, so instead of four reactors, only one was completed.
“There was a plan for how much debt would be incurred and a long-range forecast, but that changed,” said Ken Raber, former senior vice president of ElectriCities and consultant with Raber and Associates. “First the costs skyrocketed, and more energy conservation caused the load forecasts to be reduced. That resulted in the cancellation of units two through four. Money was still spent on those, but not nearly enough to finish, so we ended up with larger capital costs and less available energy.
“It was the perfect storm of prices going up, use going down, and the 1986 Tax Act gave electric utilities bigger benefits than municipalities, so that affected municipalities’ competitiveness from that point on.”
Carolina Power & Light eventually became Progress Energy, which merged with Duke in 2012. Three years later, the N.C. Eastern Municipal Power Agency sold the shares in energy generation facilities — including Harris — to Duke Energy Progress.
“The sale alleviated the majority of the debt and provided a wholesale power supply agreement that provided the 32 cities with much lower energy costs,” said Wilson Energy Director Rich Worsinger. “That allowed Wilson to reduce its cost, so we’re on par or lower than Duke.”
“Nuclear energy is still carbon-free energy, and while typically nuclear plants are expensive to construct, they are the least expensive to operate,” Worsinger said. “Once the capital cost is covered, it is pennies per kilowatt hour.”
Since the accident at Three Mile Island occurred, no new nuclear plant that has been proposed has been put into operation in the United States. However, power from six nuclear plants accounts for 49.1% of the energy generated for Duke’s customers in North Carolina and South Carolina.
“In the energy industry, there are three types of energy generation with the first handing the base load and running all the time. The second is the intermediate and follows the load, while the third is for consumption peaks,” Raber said. “The nuclear plants are put on and run full-bore the whole time. They are the workhorses of the industry and provide the foundation to the reliability of the system.”
For Duke, natural gas accounts for 26.9% of energy generated across the Carolinas, despite Duke not being in the business of natural gas extraction.
“The declining price of natural gas over the past several years has enabled us to transition away from coal and provide lower-cost, cleaner and reliable generation services to our customers,” said Meredith Archie, lead communication consultant for Duke. “The benefits of increasing the amount of electricity generated with natural gas include cleaner air, more efficient use of energy resources, bringing more renewable energy onto the grid and less dependence on imported oil.”
Archie said Duke still relies on coal for 21.3% of its energy in the Carolinas, but the company has retired 49 coal-fired units since 2010 and replaced the energy generation with flexible natural gas and renewable energy. Duke already has reduced carbon dioxide emissions by 31% of the 2005 level, and officials hope to double the portfolio of solar, wind and other renewable energies by 2025 toward the goal of cutting carbon levels to 50% by 2030.
CLEAN ENERGY WEEK
The Three Mile Island closure announcement coincided with Gov. Roy Cooper’s announcement of Sept. 23-27 as Clean Energy Week. As part of the observance, Cooper participated in a roundtable discussion last Monday about clean energy projects and measures coastal communities can take to weather Mother Nature’s fury.
“Clean energy and resiliency go hand in hand,” said Michael S. Regan, secretary of the N.C. Department of Environmental Quality. “Cutting greenhouse gas emissions from power generation will mitigate the impacts of climate change and modernizing our electric grid will help us withstand the storms of the future.”
In coordination with the announcement, Cooper released a plan for the state to work toward a clean energy future. North Carolina already is second in the nation for installed solar capacity and a national leader in energy efficiency, smart grid technology and data analytics.
Duke’s four nuclear plants in North Carolina are significant contributors to the state’s commitment to clean energy as the facilities do not burn fuel and produce no greenhouse gas emissions. In terms of fossil fuels, the cleanest is natural gas, and advancements in technology have made it increasingly more cost effective as well.
“The technology in fracking has come a long way since it was first introduced, and the environmental impact and risk is far less than people thought in the beginning,” Raber said. “It has become an exciting source of natural gas and the reason why the price of gas and oil has come down to where they are today.”
Fracking has become major business in other states, especially in Pennsylvania. Three Mile Island owner Exelon attempted to secure subsidies to make operating the facility competitive cost-wise to natural gas, but when lawmakers rebuffed the request, the Chicago-based company decided to shutter the plant.
Decommissioning of the remaining reactor, dismantling the buildings and removing the spent fuel is anticipated to take six decades and cost more than $1 billion. It took crews more than a decade to remove the fuel and remove the contaminated water from the damaged plant, but dismantling that unit won’t begin until 2041 and is expected to take 12 years.
“Three Mile Island really got people’s attention and increased the safety regulations surrounding nuclear energy,” Worsinger said.