This is a re-post from Yale Climate Connections by Karin Kirk
Many Americans these days seem unable to avoid controversy on practically any topic, so why not embrace the discord and wade into the especially volatile arena of nuclear energy? Advocates claim it’s the only way to meet global climate goals, while opponents dig in their heels over safety, national security, and radioactive waste concerns.
And then there’s money, and lots of it, involved: a frequent common thread even – or perhaps especially – on the issues most splitting opinions on all-things-nuclear.
But the debate on both sides often misses key points. A central tenet of much of the pro-nuclear rhetoric is a misleadingly gloomy portrayal of renewable energy options. Meanwhile, absolutist arguments against nuclear energy too often apply primarily to older plants no longer being built. And at times both sides tend to hang their hats on optimistic advances in technologies that may or may not become commercially available in time to make needed progress toward decarbonization.
Given a pressing need to re-think the world’s energy systems, it’s worthwhile talking about nuclear energy. But first, spurious and inflammatory claims have to be cast aside in favor of a fair appraisal of the best and quickest ways to move beyond fossil fuels.
Progress in greening the U.S. electricity grid is well underway. Coal is declining while renewables grow. But that formula goes only so far. Energy analysts point out that to decarbonize fully, a low- or no-carbon energy source is needed to fill in the gaps around the edges of intermittent generation.
Consider the case of California, a leading state in the deployment of renewables. Although solar energy handles most of the demand during the daylight hours, it cannot keep pace with evening energy use. Presently, natural gas “peaker” plants are used to complement solar and wind, continuing the state’s reliance on fossil fuels.
In order to phase out emissions from natural gas, either carbon capture needs to be added to gas power plants, or a low-carbon option can be used, such as improved renewables storage or nuclear power.
It’s important to note that not all eggs need to go into one basket. The nation’s present energy infrastructure relies on a combination of technologies, and a diverse approach seems likely to continue.
Nuclear power generates 20% of the U.S. electricity supply; it’s the single largest source of non-fossil energy generation in the U.S. and the second largest globally. But the Energy Information Administration expects nuclear’s share of electricity generation to trend down in the U.S., primarily because it’s considerably more expensive than other sources of energy.
Only two new nuclear power projects have been launched in the U.S. in the past 30 years, and both suffered major setbacks. At the V.C. Summer project in South Carolina, two new reactors were in their fifth year of construction when the power plant was abandoned – after $9 billion had been sunk into it. Construction delays, design problems, budget overruns, and bankruptcy of the company building the reactors all contributed to the demise.
The other new project is Georgia’s Vogtle Units 3 and 4 near Waynesboro. These are slated to go online in 2021, despite delays and a near doubling of the cost originally projected.
For the most part, advocates for the future of nuclear energy generally are not suggesting the building of more of the types of plants operating today. Instead, one hears about “new nuclear,” “advanced nuclear,” or “Gen IV” power plants. These terms encompass a host of emerging technologies potentially offering bold promises in improvements in safety, waste reduction, and flexibility.
Here are some concepts in the development of advanced nuclear power.
Better ways to cool reactors
Current nuclear reactors are cooled with pressurized water, which must be continuously circulated through the reactor core. If the flow of cooling water is slowed or interrupted, the reactor core can overheat, leading to a potentially calamitous meltdown. That’s what happened at the Fukushima nuclear plant in Japan, in the wake of the 2011 earthquake and tsunami.
The next generation of designs will use better ways of absorbing heat. Molten salt, for example, can absorb far more heat than water, and it can’t boil away. Other designs use liquid metal, such as sodium or molten lead, also heat absorbers.
Less waste
Radioactive waste and disposal options pose grave challenges for nuclear energy, and they raise problems without easy solutions, despite decades of engineering efforts.
Conventional reactors consume only 1% of the original uranium in the fuel, leaving behind waste products that remain dangerous for thousands of years. New reactor designs would hypothetically use fuel more efficiently, producing less waste and running longer between refueling.
One example is a breeder reactor, which uses a series of reactions to consume some of the materials that end up as waste in conventional reactors. The result is a double benefit of less waste and more energy generated per unit of fuel.
Smaller and more flexible … but when?
An acronym one hears in the debate is SMR, small modular reactor. A nuclear industry advocacy group heralds SMRs as “bright future of nuclear energy,” but follows with the stark reality that “high up-front costs and poorly designed regulations threaten to keep these technologies from reaching the market.”
The U.S. Department of Energy describes SMRs as smaller, cheaper, and safer than conventional nuclear plants. Output from each reactor would be tens to hundreds of megawatts, similar to the output of a utility-scale wind farm. And the M in SMR stands for modular: These power plants could be built incrementally, adding more modules as needed.
Although the concept of small modular reactors offers many advantages, DOE acknowledges that “Significant technology development and licensing risks remain in bringing advanced SMR designs to market, and government support is required to achieve domestic deployment of SMRs by the late 2020s or early 2030s.”
Capable of high-heat applications
Conventional nuclear reactors have one role: to make electricity. But new reactor designs can operate at sufficiently high temperatures needed for some industrial purposes. For example, steelmaking currently uses metallurgical coal, which accounts for 17% of coal usage worldwide. As coal-burning for electricity generation is being replaced by cleaner sources, there’s no obvious replacement for making steel. Nuclear energy could potentially fill this need and help further lower carbon emissions.
Similarly, advanced nuclear reactors can be used to make hydrogen, which has multiple uses in a low-carbon energy future.
The next generation of nuclear reactors is still in the R&D phase. New designs will need to be prototyped, tested, and tweaked before commercial availability and operation become viable. The Generation IV International Forum – a collaboration of 14 countries involved in R&D on new nuclear reactor designs – has evaluated 130 conceptual ideas and selected six with the most promise. The timetable for bringing these ideas to fruition is long: “Some of these reactor designs could be demonstrated within the next decade, with commercial deployment beginning in 2030.”
There are no working prototypes of advanced nuclear reactors in the U.S., but six demonstration projects have been approved by the Nuclear Regulatory Commission, and the Department of Energy recently launched a new demonstration program that aims to build two new reactors.
So at a minimum, this technology is 10 years down the road, and likely more than that with the added complexities of financing, permitting, and politicking. Given demands for rapid decarbonizing, the world may be unwilling to wait another decade until widespread solutions can begin to be implemented.
It’s hard to pin down the price of advanced nuclear technology when the end goal is years away. Nonetheless, the Energy Information Administration estimates the price of advanced nuclear to be among the most expensive options for construction of new energy sources, at $82 per Mwh, which includes capital costs, operation, and transmission. That price tag does not take into account managing nuclear waste. For comparison, natural gas “peaking” electricity is $67/Mwh, onshore wind is $40, and utility-scale solar is $36. Currently, production tax credits for solar and nuclear are available, but those discounts are not included in the price estimates above.
But given the snowballing costs of the two recent nuclear plants built in the U.S., it’s difficult to know the real price of advanced nuclear.
American politicians have yet to solve the nuclear waste problem, and many expect political hurdles may well outlast technological ones. A long-term, underground disposal site at Yucca Mountain, Nevada, for instance, has been in the works since 1987, but was never completed, largely for political reasons (including the reality that then-U.S. Senator Harry Reid (D-Nevada) was the Senate Majority Leader and a powerful opponent from 2007 to 2015). Instead, spent fuel rods are stored at power plants as they await a longer-term fate.
Even the much-heralded breeder reactors still produce radioactive waste, albeit less than their predecessors. Nuclear waste presents both an engineering problem and a social problem, because most people want nuclear waste to go somewhere far away from them. For the industry to find a credible path forward, unresolved waste, economic, national security, and sociopolitical concerns need to be resolved.
Given the long lead-time for developing new nuclear reactors and the sky-high costs relative to other energy options, the nuclear option remains a tough sell for many private investors. Projects of any meaningful scale require government investment – and here’s the rub: Nuclear energy remains unpopular with much of the American public, a perception that persists whether energy wonks like it or not. According to Pew Research polling, just 43% of Americans favor building more nuclear plants. By contrast, 90% of Americans support expanding solar energy and 83% favor increasing wind energy.
The massive investments, long lead-time, and lack of public enthusiasm make for a continued tough road ahead for nuclear energy in the U.S.
Proponents of nuclear energy often dismiss a vast scale-up of wind and solar as “magical thinking.” But moving to advanced forms of nuclear energy also requires a substantial dose of optimism in the face of potentially stark challenges.
Prevailing public opinion on renewable energy – fueled by lower costs – gives it a big head start over advanced nuclear energy: It’s popular and, in comparison, cheap. But that alone is insufficient. Considerable progress in energy storage is needed to bring renewable energy into the hard-to-fix areas of the energy system, like multi-day cloudy or cold spells, steelmaking, and burgeoning energy demand globally. The necessary gains in renewable energy will be possible only if there is public will and substantial investment.
Turning to nuclear energy, several of the same things are true. There is no existing technology that can get the job done. Serious improvements are needed, the price tag is unknown, and the timeline is worryingly long.
Unlike some current political debates, energy is not a simple up-or-down vote. It may be a false dichotomy that the nation’s energy future has to be either renewables or nuclear. It’s neither necessary nor helpful to build a case for one by simply squelching all consideration of another. There may be no “perfect” solution, and all the individual pieces of the puzzle will have to be hashed out in the context of science, technology, engineering, economics, and, of course, politics.
In the end, transforming the world’s energy grid in just a decade or two is no easy task. Fossil fuel interests, politicization, and business-as-usual inertia have tied the world’s hands for decades, leaving a tight timeline for scaling up solutions. Perhaps the worst kind of magical thinking is that the climate crisis is solvable without creative and large-scale action.
But taking one step farther back, a few things are glaringly obvious: Smart planning, big investments, science-based strong leadership, and a motivated populace are precisely what’s needed. While we can argue about the details ad infinitum, perhaps we can also agree to stay focused on the end goal, dream big, and move forward boldly.
Posted by Guest Author on Monday, 3 August, 2020
 |
The Skeptical Science website by Skeptical Science is licensed under a Creative Commons Attribution 3.0 Unported License. |