Nuclear power in the U.S. and globally has battled headwinds in recent years, and not just from the growth of other power generation resources such as solar, wind, and natural gas.
Problems in the U.S. nuclear sector, such as construction delays and cost overruns at the Vogtle site in Georgia, the cancellation of the V.C. Summer project in South Carolina, and continued debate about where to store nuclear waste—not to mention the retirement or scheduled closures of several iconic U.S. nuclear plants—have dogged the industry.
The push toward carbon-free power, though, and government policies more favorable for nuclear have spurred research into new technologies. David Kropaczek, director for the U.S. Department of Energy (DOE) Innovation Hub – Consortium for Advanced Simulation of Light Water Reactors (CASL), recently spoke with POWER about nuclear power and what his group is doing in its research and development of nuclear technology.
POWER: Nuclear power faces several challenges in the U.S. What needs to happen to keep nuclear power viable in this country? What is needed to spur construction of more nuclear plants? Is that even a possibility?
Kropaczek: “I think the cost competitiveness is a big deal. Look at the current generation of small modular reactors [SMRs], designed to have smaller footprints. It’s the capital costs [of large nuclear plants] that are going to get you. So take a smaller modular design, that can be added to the grid [at less cost], and you bring those capital costs down.
“Look at the GE SMR. It can be buried underground, which reduces the risk of inadvertent release of radioactivity. It has a small footprint, and it can be added incrementally to the grid at low capital cost.”
(Editor’s note: GE is developing its BWRX-300—a 300-MWe small modular boiling water reactor—with Hitachi. The companies have said a unit could be deployable as early as 2028. Analysts have said that among other things it could help revive Japan’s nuclear power industry, which has been slow to recover after the Fukushima disaster in 2011.)
POWER: What does the U.S. nuclear power industry need to improve its fortunes?
Kropaczek: “I think somebody’s gotta step up [to invest in nuclear]. The equation should change economically. No utility wants to be first [to invest], they want to be first in line to be second. If you can demonstrate the lower capital costs, then you’ve got a good winning formula. If you’re a utility, of course, you want a mix of energy options, you don’t want all your eggs in one basket.
“Nuclear has a fairly good track record, once operating. It’s stable. It can go for 60 years, or 80 years or beyond, depending on the operating license.
“Nuclear is carbon-free production, and it makes up 20% of our carbon-free electricity. We’ve got 98 plants operating [in the U.S.], and with every plant we take off the grid, that carbon [emissions] number will go up. Can you afford to replace all nuclear with solar and wind and so on? The answer is no, unless you want to [slow] down your economy.”
(Editor’s note: Kropaczek pointed to Germany as an example of an economy that has suffered as nuclear power has been retired. The Economist, in late 2015, noted that French power consumers pay about half as much as German ratepayers for electricity. “Germany has made unusually big mistakes,” The Economist reported. “Handing out enormous long-term subsidies to solar farms was unwise; abolishing nuclear power so quickly is crazy. … But Germany’s biggest error is one commonly committed by countries that are trying to move away from fossil fuels and towards renewables. It is to ignore the fact that wind and solar power impose costs on the entire energy system, which go up more than proportionately as they add more.”)
Kropaczek: “France is clearly meeting all their targets because they’re predominantly nuclear. We keep hearing, we’ve got 12 years to meet our carbon targets. Sensible policy would say nuclear has got to be part of that mix going forward. You’ve got to have a mix [that includes nuclear]. You’ve got one really good carbon-free source, that’s really high energy density, that can put out electrons to the grid.”
POWER: What about the continuing debate about where to store nuclear waste?
Kropaczek: “Nuclear waste, it’s a relatively small amount compared to [coal ash]. It’s a manageable problem. There’s going to be a national repository. Most of that fuel is still there, we’ve only burned a small fraction of uranium, there’s still plutonium there. The next generation of reactors, the fast reactors, can reuse that light reactor fuel.”
POWER: What about light water reactors sets that technology apart, or above, other nuclear power technologies?
Kropaczek: “Light water reactors was the earliest technology, adopted by the Navy program. They said, ‘Let’s make a submarine that can go for months and months on end. A lifetime core that doesn’t need to be refueled.’ We understand water quite well, so the light water reactor was logical.
“There were other concepts, molten salt reactors, that proved effective. The fuel is already melted, [so] there’s no such thing as a meltdown. The light water reactor technology was quickest to implement. You had Westinghouse picking up the technology and running with it. There were other various concepts tested and tried, and maybe [those technologies] were not mature enough. Our new advanced reactors are kind of a recycling of the old technologies, but with new materials and operating methods.
“Light water reactors, our vessels are lasting 60 years, they can survive radiation damage. We know how [the] fuel performs. I think light water reactors have had an advantage because of the understanding of the technology, and now it’s established technology.”
POWER: What are some of the innovative technologies being researched and developed?
Kropaczek: “CASL was one of the Obama-era hubs for energy innovation, founded in 2010. It was a different model that engaged a single-roof model, bringing together industry, DOE, academia, along with a number of founding partners: Westinghouse, TVA [Tennessee Valley Authority], EPRI [Electric Power Research Institute].
“Oak Ridge [in Tennessee] is the host lab, and we work with Idaho, Los Alamos, Sandia. The focus of CASL is on simulation, what do [you] have to develop to attack and solve these types of problems, such as multi-HYSYS, many difference physics interacting, chemistry, thermal hydraulics, boiling water, how does that interact with the reactor, software that comes out of it, toward new applications.
“I came on as [CASL] director in August 2018, and we’re in the final push for the end. The hub has a definite ending point. It’s a pretty good story, you have high, advanced computing along with simulation. The technology is at the point where’s it’s a cost argument. You’ve got to lower the capital cost. The [nuclear] technologies are mature, at least on the SMR front. You’ve got to be able to demonstrate that the costs are going to allow you to make money … [you’ve got to] tell me how a utility is going to be able to make money [with nuclear power] above an alternative, like a combined cycle gas turbine.
“I think it can be done by adding capacity at existing nuclear sites, especially underground. Microreactors that can be delivered on a rail. Put it up, start it up. These are a lot lower megawatt range. The era of the big power plants is probably nearing its end. Now you’ll have a lot more of these modular [designs]. The cost of producing a lot more smaller modulars … it’s economy of scale. Instead of these large castings [for reactors], you’ve got smaller manufacturing castings. Make the components a lot faster, put it out in three months rather than a couple of years.
“Can we build big things anymore? You can get good by doing a lot of small things. I think [smaller] is the future of nuclear going forward. It depends on where you are in the market.”
—Darrell Proctor is a POWER associate editor (@DarrellProctor1, @POWERmagazine).