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Capacity factor is a measure of reliability, and reliability delivers results. The U.S. nuclear power fleet produced about 789.9 TWh of clean electricity in 2020 and ended the year with 94 operating reactors. According to Energy Information Administration data, that’s about 37 percent more electricity than the 576.9 TWh produced in 1990 by a much larger fleet of 112 reactors.

Nuclear News has tracked and analyzed the capacity factors of the U.S. fleet since the early 1980s, before concerted industry efforts yielded unforeseen performance improvements. High nuclear capacity factors are now less an achievement than an expectation. So much so, in fact, that advanced reactors in development today are assumed to be capable of achieving capacity factors above 90 or even 95 percent.

The U.S. fleet has maintained a median capacity factor near 90 percent for 20 years (see Fig. 1), and the median design electrical rating (DER) net capacity factor for 2018–2020, at 91.33, does not disappoint—unless by showing virtually no change relative to the median of 91.34 recorded in 2015–2017. However, this lack of meaningful difference only underscores the consistent reliability of the U.S. fleet.

The viability of nuclear power ultimately depends on economics. Safety is a requirement, but it does not determine whether a reactor will be deployed. The most economical reactor maximizes revenue while minimizing costs. The lowest-cost reactor is not necessarily the most economical reactor. Different markets impose different requirements on reactors. If the capital cost of Reactor A is 50 percent more than Reactor B but has characteristics that double the revenue, the most economical reactor is Reactor A.

The most important factor is an efficient supply chain, including on-site construction practices. This is the basis for the low capital cost of light water reactors from China and South Korea. The design of the reactor can significantly affect capital cost through its impact on the supply chain. The question is, how can advanced reactors boost revenue and reduce costs?

At present, more than 20 commercial nuclear power plants in the United States have entered the decommissioning process, and many indicators point to a coming wave of additional plant closures. Indeed, with increasing numbers of plants terminating operations due to unfavorable market conditions, some voices have deemed this the “age of decommissioning.”

Regardless of whether a plant shuts its doors earlier than antici­pated or seeks a life extension through relicensing, all plants eventually close. When they do, the closure sets off a wave of economic impacts ranging from minor disruptions to severe and long-lasting harm.

When on May 7, 2013, the Kewaunee nuclear power plant in rural Wisconsin was shut down, it took with it more than 600 full-time jobs and more than $70 million in lost wages, not including temporary employment from refueling and maintenance outages. Taking into account indirect business-to-business activity, the total economic impact of the closure of the single-unit pressurized water reactor was estimated to be more than $630 million to the surrounding three-county area.

If there is one U.S. state you might think would be on top of the nuclear-plant-retirement problem, it’s Illinois: With 11 power reactors, more than any other state, it is number one in nuclear generating capacity. In 2019, 54 percent of its in-state generation came from nuclear power. So why, at this writing in mid-April, does Illinois still face the possibility of losing two of its nuclear plants later this year?

The health and safety of the public and protecting people from the consequences of a significant release of radioactive material has been a top priority since the early days of the civilian nuclear energy program. After World War II, it was realized that the core inventory of radionuclides is a potential hazard. From this knowledge, emergency planning zones (EPZs) for nuclear power plants were established.

To build a next-generation nuclear reactor, you can teach it how to build itself

The nuclear reactors currently in operation in the United States are beginning to gray around the temples. Built decades ago using technology developed during the middle of the 20th century, these reactors have safely and reliably powered homes and businesses, but they produce waste that must be disposed of properly.

Nuclear power plants not only provide the nation’s largest source of carbon-­free electricity, they also can operate 24 hours a day, 365 days a year to augment intermittent renewables such as wind and solar. Further, studies show that nuclear energy is among the safest forms of energy production, especially when considering factors such as industrial accidents and disease associated with fossil fuel emissions. All said, nuclear has the potential to play a key role in the world’s energy future. Before nuclear can realize that potential, however, researchers and industry must overcome one big challenge: cost.

A team at Idaho National Laboratory is collaborating with experts around the nation to tackle a major piece of the infrastructure equation: earthquake resilience. INL’s Facility Risk Group is taking a multipronged approach to reduce the amount of concrete, rebar, and other infrastructure needed to improve the seismic safety of advanced reactors while also substantially reducing capital costs. The effort is part of a collaboration between INL, industry, the Department of Energy’s Advanced Research Projects Agency–Energy (ARPA-­E), and the State University of New York–Buffalo (SUNY Buffalo).

Sooner or later, any discussion of the future of the role of nuclear power leads to the question, “What are you going to do with the waste?” Nuclear technology professionals recognize that there are good solutions available for the management and disposal of nuclear waste, but implementing them requires overcoming societal and political barriers that have proven daunting in this country. Currently, the United States has a nuclear waste policy, but the federal government lacks the will to implement it or change it. The past decade has been extremely frustrating to those dedicated to addressing waste issues here and now, rather than kicking them down the road. Prospects for the next decade are uncertain, at best.

The Fukushima Daiichi site before the accident. All images are provided courtesy of TEPCO unless noted otherwise.

It was a rather normal day back on March 11, 2011, at the Fukushima Daiichi nuclear plant before 2:45 p.m. That was the time when the Great Tohoku Earthquake struck, followed by a massive tsunami that caused three reactor meltdowns and forever changed the nuclear power industry in Japan and worldwide. Now, 10 years later, much has been learned and done to improve nuclear safety, and despite many challenges, significant progress is being made to decontaminate and defuel the extensively damaged Fukushima Daiichi reactor site. This is a summary of what happened, progress to date, current situation, and the outlook for the future there.

In 2015, we wrote an article for Nuclear News analyzing the history of commissioners appointed to the Nuclear Regulatory Commission and assessing their backgrounds, experience, and qualifications at the time of their appointment. At the time, ANS had not established a formal position statement on NRC commissioner appointees. Our article provided an objective assessment of historical patterns and was used to develop ANS position statement #77, The Nuclear Regulatory Commission (2016). This article draws upon the 2015 article and provides updated data and analysis. Also, the recommendations of the position statement are applied to the current vacancy on the commission.

Students display items they received at a STEM workshop sponsored by Exelon. Photo: Exelon.

The landscape of Exelon Generation’s nuclear business has continued to evolve—even before the complications of a pandemic—but people will always remain the core focus. Our employees and our future employee pipelines are changing almost as fast as technology, which is why the development of the workforce, both present and future, along with the transfer of knowledge across all departments and levels of the organization, must remain adaptable and advance as well.

Fusion devices have yet to sustain a burning plasma and produce usable energy, so it should come as no surprise that there is not yet a framework for regulating commercial fusion energy.

Fusion and fission are two very different ways to release nuclear energy. But how different could their regulation be? There are many possible answers to two central questions: Who will regulate commercial fusion (in the United States, that authority could reside with the Nuclear Regulatory Commission or an Agreement State operating under NRC oversight), and what aspects of a fusion plant will they regulate?

Fusion energy is no longer a far-off goal. It is now routinely achieved at laboratory scale but requires more energy to control the fusion reaction than the fusion reaction has released.

The path to viable fusion power from a magnetically confined plasma source requires the creation of a burning plasma, whereby the primary heating source comes from the fusion reaction itself.

To begin to consider the economic viability of a fusion power plant, the reaction must have a significant energy gain, or “Q” factor (the ratio of output power to input heating power), in a reaction that is sustained over a time frame of minutes or hours.

Construction has begun on an international experiment—the ITER tokamak—that aims to achieve a sustained reaction, and numerous privately funded smaller experiments have the potential to move forward toward this goal.

Nuclear News reached out to companies in the fusion community to ask for insights into their ongoing work. All are members of the Fusion Industry Association. Most companies submitted briefs at a specified word count, while others ran long and some ran short. Their insights appear on the following pages.

The ST25-HTS tokamak.

Governments around the world have been interested in fusion for more than 70 years. Fusion research was largely secret until 1968, when the Soviets unveiled exciting results from their tokamak (a magnetic confinement fusion device with a particular configuration that produces a toroidal plasma). The Soviets realized that tokamaks were not useful as weapons but could produce plasma in the million-degree temperature range to demonstrate Soviet scientific and technical prowess to the world.

Following this breakthrough, government laboratories around the world continued to pursue various methods of confining hot plasma to understand plasma physics under extreme conditions, getting closer and closer to the conditions necessary for fusion energy production. Tokamaks have been by far the most successful configuration. In the 1990s, the Tokamak Fusion Test Reactor at the Princeton Plasma Physics Laboratory produced 10 MW of fusion power using deuterium-tritium fusion. A few years later, the Joint European Torus (JET) in the United Kingdom increased that to 16 MW, getting close to breakeven using 24 MW of power to heat the plasma.

Today’s U.S. commercial nuclear power plants are fueled with uranium dioxide pressed into cylindrical ceramic pellets—and have been for decades. These pellets are stacked inside long fuel rods made of a zirconium alloy cladding. Innovation in nuclear fuel, however, can improve safety, reduce operating costs, and further enable the development of a new generation of non-light-water reactors.

(photo: ITER Project gangway assembly)

The promise of hydrogen fusion as a safe, environmentally friendly, and virtually unlimited source of energy has motivated scientists and engineers for decades. For the general public, the pace of fusion research and development may at times appear to be slow. But for those on the inside, who understand both the technological challenges involved and the transformative impact that fusion can bring to human society in terms of the security of the long-term world energy supply, the extended investment is well worth it.

Failure is not an option.

Workers in nuclear must be free to report potential problems without fear of retaliation. When it comes to issuing adverse actions, employers have a responsibility to ensure that protected activity rights are not infringed.