One of today’s toughest energy questions concerns nuclear power. Will it play a large or small role in the future of electricity in the United States?
As a nation, we’re looking for ways to have reliable electricity that make sense on many different levels.
We want affordable energy.
And we want energy that suits our ideas of politically and socially acceptable behavior.
And we want energy that doesn’t cause too many problems for the natural environment.
That’s quite a list.
Nuclear power plants don’t use fossil fuels, so they sound like a great way to get more electricity without adding carbon dioxide or other greenhouse gases to the Earth’s atmosphere.
But whether Americans say yes or no to more nuclear power depends on a firm understanding of exactly what’s involved in increasing the use of nuclear fuels to produce electricity.
Today, we’re already living with two forms of dependable electricity production—nuclear and hydro—that do not emit greenhouse gases.
At a hydroelectric power plant, the force of falling water turns turbines that spin to generate electricity. This kind of conventional hydropower accounts for about 7 percent of the electricity supply in this country. Hydroelectric power plants work all day and all night. Variations in the natural cycles of rain and snowmelt cause minor changes in the amount of electricity produced from one year to another.
There are nearly 4,000 hydroelectric generators in use throughout the United States. Since the most useful sites for hydro plants have been connected to the grid for decades, there aren’t many prospects for increasing the use of this nonfossil-fuel resource.
Nuclear power is different.
Today, nuclear power plants contribute much more to the nation’s power grid—from 16 to 19 percent, depending on how many plants are shut down for regular maintenance. Total production of electricity from nuclear resources recently increased when a previously fire-damaged reactor at the Tennessee Valley Authority Browns Ferry site in Alabama came back online in May 2007.
TVA’s three reactors at Browns Ferry, plus others at Sequoyah and Watts Bar, generate more than 6,900 megawatts—enough to provide electricity to more than three and a half million homes.
Throughout America, 104 nuclear reactors supply power to the transmission grid for homes and businesses. But many of these reactors are reaching the end of their originally planned operating periods. There are several options to extend their useful lives.
Unlike hydropower, there are potential sites where new nuclear generating plants could be built.
But will that happen?
When electric utility experts talk about reliability, what they mean is that there is a steady source of electricity flowing through the grid with no interruptions. They often use the term “base load,” which means the basic minimum amount of electricity that all customers within a geographic area need during a particular time. A base load plant generates that amount of electric power year-round.
Coal plays a major role in meeting the base load demand for reliable electricity. Historically, coal has been the backbone of America’s electricity generating systems, supplying about 50 percent of power nationally. However, concerns over the emissions of greenhouse gases are changing attitudes toward generating plants that use fossil fuels.
John Holt, senior principal for Generation and Fuel at the National Rural Electric Cooperative Association, says, “Many applicants for new coal generation plants have not been able to obtain permits to begin construction.”
Holt notes that although nongreenhouse gas emitting renewable energy sources, such as wind and solar, have value, they do not provide the same massive amounts of around-the-clock electricity needed to meet customer demands. Base load generation—power in megawatt quantities—must continue to come from nonintermittent resources.
What fuels will we choose?
Each year, the U.S. Energy Information Agency looks at all forms of energy production and consumption. Changing attitudes throughout America, and an array of new local and state initiatives setting goals for everything from renewable resource percentages to energy self-sufficiency, make this year’s report remarkably different from other recent years’ assessments.
David Mohre, executive director for the Energy and Power Division of the National Rural Electric Cooperative Association, says, “According to the Energy Information Agency’s own reports in 2008, nuclear is going to have to play a much larger role in electricity in the future than it has historically, because there may be fewer coal plants built due to global warming concerns.”
Two years ago, those concerns inspired the Electric Power Research Institute, a nonprofit electric utility industry group, to ask its 800 members to take a look at how technology could help reduce greenhouse gas emissions. Known as the PRISM report, EPRI’s study, released in 2007, spells out in detail how a lot of different kinds of technology in seven areas, including nuclear power, could be put into use over the next several decades.
The PRISM report is very different from the Energy Information Agency’s annual energy outlook. The EPRI report does not predict which kinds of technological advancements are more or less likely to happen. Instead, the PRISM report examines various possibilities for short- and long-term implementation of new technologies.
In the nuclear power segment, the PRISM report highlights several ways in which nuclear power could be made more useful with improvements over today’s technology.
An important area concerns the age of America’s current commercial nuclear fleet. These old plants, known as light water reactors (LWR), are efficient, yet there is a lot of room for improvement in their day-to-day operations.
A great many of these plants are at or near the end of their original operating license periods. A few have already asked for extensions so they can continue to operate; most others are expected to do so before the end of this year.
Extending the working life of these older plants could also be an important temporary step while working on an improved design for any new nuclear power plant construction. Known as advanced light water reactors, this newer design will be more efficient and feature new safety and control techniques. Advanced light water plants are already in use or under construction in Japan, Korea, Taiwan, France, and Finland.
American engineers and designers have been working for about 20 years to create an advanced light water model for the United States.
So far, the U.S. Nuclear Regulatory Commission has approved two advanced light water reactor styles. However, industry experts predict it will be several more years before construction could begin on one of these new designs, with electricity not being generated from these newer-style nuclear plants until 2015 at the earliest.
Improving fuel efficiency
Another key nuclear technology issue involves the radioactive fuel itself.
American nuclear power plants currently in operation are of the “once through” design—that is, after each bit of enriched uranium is used to produce heat within the reactor, it becomes a waste product.
Dealing with this spent fuel is an issue that still has no long-term solution. Today, nuclear power plant waste (including the used uranium and a variety of other radioactively contaminated items such as workers’ clothing and tools) is being stored onsite at individual nuclear power plants temporarily.
Plans and laws to set up a permanent central storage site keep seesawing through various courts, with no one certain of the eventual outcome. The earliest possible date that nuclear waste could be stored at Yucca Mountain, Nevada, is now estimated to be more than a decade in the future; even if legal battles were resolved this year, containers of nuclear waste won’t go there until at least the year 2021. What routes those containers would travel on their way to Yucca Mountain adds a further complication: many states that do not have nuclear power plants within their borders do not want any nuclear waste transported over their highways or railroads.
The EPRI PRISM report notes that improved technology could make nuclear waste less of a problem if new power plants made use of an improved system known as a “closed fuel cycle.”
This technology would allow the radioactive uranium to be reprocessed to wring every bit of energy from it—and presumably make the waste product less dangerous and less difficult to store at the end. The closed fuel cycle nuclear power plant design would be a very high-tech form of recycling.
There’s another way to improve nuclear power plant efficiency with improved technology. In a very sophisticated twist on the old concept of co-generation (using steam or heat for more than one purpose), a high-temperature gas reactor would allow the immense heat released during the nuclear reactions to be used as part of industrial processes. Key industries that could benefit from this kind of dual-purpose effort are those that use huge amounts of electricity or release lots of greenhouse gases, namely, hydrogen production, petrochemical production, and desalinization plants for water. Using the steam from nuclear reactors for these additional purposes could result in substantial reductions in many kinds of emissions.
NUCLEAR POWER IN KENTUCKY—YES & NO
The United States Enrichment Corporation, a subsidiary of a multi-national energy company, operates the only uranium enrichment facility in the United States at a gaseous diffusion plant in Paducah. The plant makes fuel for nuclear reactors.
However, Kentucky state law prohibits the construction of any nuclear power plant within the borders of the Bluegrass State until there is a licensed and available location somewhere within the United States for the permanent disposal of nuclear waste.
To find out what fuels the Department of Energy predicts will be producing our electricity in the year 2030 go to 2030.