Nuclear power is currently the only carbon-free energy source that can provide base load electricity, Stepp writes, a characteristic crucial to reducing global greenhouse gas emissions and fighting climate change. Next-generation nuclear energy offers even more productive strategies for reducing carbon emissions.
Mary Ann Chastain/AP/File
In the last week, two news stories really captured the potential future for nuclear energy. The New York Times Matthew Wald reported from Georgia, where construction crews are slowly building the first two new nuclear reactors in thirty years. And National Geographic’s Will Ferguson reported from Tennessee that engineers and scientists are taking core samples and mapping regional geology as part of the early planning stages of building the first small modular nuclear reactor in the world. Both projects face unique challenges, yet they both represent the beginning of two potential nuclear paths for reducing climate-warming carbon emissions in the United States (and potentially the world).
The nuclear generators we are all familiar with is physically recognized by large, curved cooling towers and billowing white steam, and pragmatically recognized as a significant source of carbon-free electricity. Big-box nuclear reactors across the United States provide about 19 percent of all electricity.
But for thirty years, the nuclear energy industry has remained stagnant. Due to a mix of factors including more stringent regulation, rising construction costs, falling fossil fuel prices, and the Three Mile Island meltdown, no new nuclear power plants were developed. That changed in 2009, when the Department of Energy provided an $8.3 billion loan guarantee for the Alvin Vogtle nuclear project, aimed at constructing two new reactors. In 2012, the Nuclear Regulatory Commission (NRC) gave its approval and construction began. Vogtle, along with the two reactors under construction at the Virgil Summer Nuclear Generating Station in South Carolina, represent the “next-generation” of large-scale, traditional nuclear power.
In particular, the $14 billion 2234 MW Vogtle project utilizes two innovations, one regulatory and the other technological. The first innovation is the projects use of the NRC’s combined construction and operating licensing agreement. Previous to Vogtle, nuclear plants received one NRC license previous to construction and then one after construction, but before operation. The split-process added considerable cost and delay to new power plant construction, which in some cases stalled or completely stopped operation of constructed plant. Most famously, the Shoreham nuclear site on Long Island incurred cost overruns due to NRC regulatory changes and ultimately never began full operation after local authorities failed to provide evacuation plans required for licensing.
Instead the new combined license process requires overcoming development barriers before construction begins. The NRC does so by pre-approving the reactor design, which provides regulatory certainty and reduces potential cost overruns during construction. NRC pre-approved Vogtle’s (and Summer’s) chosen reactor design – the Westinghouse AP1000 – in 2011.
The second innovation is the AP1000 nuclear reactor design itself. It’s the most advanced pressurized water reactor ready for commercial use and purports to be safer and more reliable than existing reactors. In particular, the AP1000 utilizes a passive cooling system that can automatically keep the reactor safe from meltdown for at least three days without any operator interaction. It also produces more energy, but houses less pumps, pipes, and valves compared to previous generation designs, further increasing safety and reducing costs.
While the nuclear industry continues to push for more construction of big-box nuclear plants, emerging technologies are showing progress. In particular, small modular nuclear reactors (SMRs) are taking the first step from theoretical design to commercial pilot projects.
SMR innovations potentially solve a key problem with traditional nuclear technologies: up-front costs. While nuclear-generated electricity is relatively cheap once operation begins, it can cost $10 to $20 billion to successfully develop a new plant — something only a handful of energy companies are capable of doing even with federal loan guarantees. SMR companies believe they can construct a plant for roughly $2 billion, or one-fifth the cost. Of course, one SMR reactor won’t provide the same output as one big-box reactor, but this actually creates flexibility. SMRs can be stacked together to meet a particular region’s power need, so less populated regions can invest in less SMR reactors while more populous regions can add more, if necessary. Power generators can also begin operating SMRs even while installing additional modules, so energy companies can begin recouping up-front costs much earlier than if building a large traditional reactor, which can’t be turned on until construction is complete.
SMR companies hold that additional cost reductions will come from the potential to mass-manufacture SMR reactors and ship to construction sites rather than on-site assembly of big-box plants (though, some parts of the Vogtle project are doing this as well). In addition, SMRs provide unique safety benefits, such as the potential for air-cooled passive safety systems, rather than traditional water cooled systems used today, as well as the ability to remove the entire reactor in one piece rather than disassemble it piece by piece.
The Tennessee SMR project developing along the Clinch River is the first demonstration under the Department of Energy’s SMR program. Specifically, the DOE is investing $452 million over 5 years to accelerate the licensing of SMR designs to provide regulatory certainty so that private companies can begin developing them across the United States. Babcock & Wilcox’s mPower design — an 180 MW pressurized water reactor— is the first to gain support from the program to begin completing design certification, the aforementioned site geology, NRC design licensing, and early-stage engineering activities. The project has access to a unique partnership with the publically-funded Tennessee Valley Authority (TVA), which could act as an end-use customer once the SMR is constructed. DOE has a solicitation to support a second next-generation design, which it intends to announce by the end of the year.
Nuclear is currently the only carbon-free energy source that can provide base load electricity — a characteristic crucial to reducing global greenhouse gas emissions. In contrast, renewables at increasingly high penetration rates require either utility-scale energy storage (which isn’t cost or performance competitive yet) or peaking natural gas plants to balance spikes in demand. In fact, California’s carbon emissions are set to increasebecause it closed the San Onofre nuclear generating station, which produced one-tenth of California’s electricity, and is quickly working to replace it with a mix of natural gas and renewable technologies. The same situation has occurred in Germany and Japan.
Like renewable energy the critical barriers to large-scale nuclear deployment are cost and uncertainty. With big-box nuclear plants, cost and construction setbacks continue to plague development. As Matthew Wald found, Vogtle’s construction, “…is not going as planned, and that the schedule — which is closely linked to cost…has slipped by at least 14 months and possibly more.” And as Will Ferguson reported, DOE’s SMR support only extends to licensing and early-siting, not construction. As of today, no power provider, including the TVA, has agreed to actually finance the SMR demonstration once licensing is complete.
Up-front costs of big-box plants and the valley-of-death support for SMRs are the most immediate barriers to expanding nuclear power. It’s not clear whether big-box nuclear energy will ever reduce its cost-overruns and SMRs may make this issue entirely moot by providing a cost-competitive alternative. And of course, these projects are in addition to DOE research investments to develop next-generation designs, materials, and safety technologies as well as continuing work in fusion energy. Nonetheless, there is substantial opportunity to incorporate next-generation nuclear energy — through either large, advanced reactors or emerging SMR designs or both — more significantly into a productive strategy for reducing carbon emissions in the long and short term.