Features

Amy Roma

Flipping on a light switch and knowing that the power will come on is a luxury. While it sounds like a simple act, it is achieved through deliberate government policies that ensure our electricity comes from a mix of sources, some of which are continuously operational—such as nuclear and gas—and some of which only operate at certain times—such as wind and solar. If any one source is unavailable or overly expensive, another source needs to deliver on demand. Diversity of energy sources ensures the grid is able to adapt and recover from changing conditions so that we can always flip the lights on.

While grid resilience—the grid’s ability to anticipate, absorb, and recover from major disruptions and rapidly restore electric service in their wake—is a matter of paramount importance, the source diversity required to achieve this is at risk. For power grids relying on renewables, supply and demand hang in a balance based on time of day and weather.

On December 20, 1951, researchers used energy produced by Experimental Breeder Reactor-I near Arco, Idaho, to illuminate four 200-watt lightbulbs. Since then, utilities have built commercial nuclear power plants in the United States almost exclusively to generate electricity. This has worked well alongside other power generation and transmission infrastructure—large oil- and coal-fired, natural gas turbine or hydroelectric plants, and a relatively simple electrical grid designed to deliver reliable power.

Humanity is now embarking on an epic and complex energy transformation across the grid, industry, and transportation. Renewables like wind and solar are contributing an increasing share of carbon-free electricity to the grid, but that contribution is variable and hard to predict—sometimes those sources produce more electricity than the grid needs, and sometimes less.

Craig Piercy
cpiercy@ans.org

This month’s Nuclear News takes a look at nuclear’s reliability as an energy source, along with its contributions to the overall resiliency of our electricity grid. Capacity factors in the U.S. remain at an all-time high, and nuclear’s strength in maintaining a functional electricity distribution system in times of stress, whether by storm or war, is gaining public acceptance and appreciation.

Earlier this spring, the Nuclear Regulatory Commission hosted its first in-person Regulatory Information Conference (RIC) since the onset of COVID. Though well organized and informative, it was easy to sense the frustration of attendees—over things like the stringency of the NRC’s proposed Part 53 regulatory framework for advanced reactors and the perceived lack of preparedness for the coming onslaught of license applications. There was a general sense, as one friend put it, that the commission is “wrapped around the axle of administrative procedures and precedents.”

Steven Arndt
president@ans.org

In our daily lives, most of us take for granted that electricity will be available. We pull up to our garages in our cars and push the garage door opener and it works. Our refrigerators stay cold. Our houses stay warm. Our lights come on when we flip the switch. But reliable electricity doesn’t happen by accident. One of the most important parts of our industrial infrastructure, a reliable electric grid is achieved through deliberate design that uses a mix of sources that can achieve reliability, low cost, and other specific attributes like low environmental impact. Maintaining a reliable electric grid requires planning, analysis, and understanding of what is happening in the world. Many of the traditional grid reliability standards no longer recognize the reality of today’s constrained electric grids, nor do they account for fuel supply, weather, or the high penetration of renewables.

Forty years ago, Nuclear News published an analysis of U.S. nuclear plant operations over the three years that followed the Three Mile Island-2 accident in 1979, scrutinizing capacity factors as a measure of how well a reactor was performing compared to its potential. The purpose: “To call attention to the units that have had the best results, and to explore the question: What have the personnel at these top units been doing right?”

Abilene Christian University’s Nuclear Energy eXperimental Testing (NEXT) Lab continues to make progress toward building a molten salt research reactor (MSRR) on the university’s campus. NEXT Lab submitted an application for a construction permit to the Nuclear Regulatory Commission last August, and in November the agency announced it had docketed the application—the first for a new research reactor in more than 30 years.

Under the Radioisotope Power Systems Program, NASA and the Department of Energy have been advancing a novel radioisotope power system (RPS) based on dynamic energy conversion. This approach will manifest a dynamic RPS (DRPS) option with a conversion efficiency at least three times greater than a thermoelectric-based RPS. Significant progress has recently been made toward this end. A one-year system design phase has been completed by NASA industry partner Aerojet Rocketdyne, which resulted in a DRPS with power of 300 watts-electric (W_e) with convertor-level redundancy. In-house technology development at the NASA Glenn Research Center (GRC) has demonstrated the conversion devices in relevant environments and has shown all requirements can be met. Progress has also been made on the control electronics necessary for dynamic energy conversion. Flight-like controllers were recently upgraded and achieved an 11-percentage-point increase in efficiency. Control architectures have been developed to handle the multiconvertor arrangements in the latest DRPS design. A system-level DRPS testbed is currently being assembled that will experimentally demonstrate the DRPS concept being pursued.

Craig Piercy
cpiercy@ans.org

Dear member:

Hello from our temporary headquarters in Downers Grove, Ill. Yes, after two years of twists and turns, we have finally completed the sale of our legacy La Grange Park property and are in the process of building out our new space, which will be ready for occupancy later this year.

I know many of you have memories made in “the Schoolhouse,” which served as American Nuclear Society headquarters for nearly 50 years. At one time during the golden age of paper recordkeeping, it housed nearly 100 employees. As the business of running a professional society evolved with the information age, however, so too did our workforce and space needs. Stately though it was, 555 Kensington Avenue proved simply too expensive to heat, cool, mow, plow, and otherwise maintain to an acceptable standard.

Fusion energy research has seen exciting recent breakthroughs. The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory has achieved ignition,^1,2 and in the United Kingdom, the Culham Centre for Fusion Energy’s Joint European Torus (JET) has produced a record 59 megajoules of fusion energy.³ Against this backdrop of advances, we provide an account of the earliest fusion discoveries from the 1930s to the 1950s.* Some of this technical history has not been previously appreciated—most notably the first 1938 reporting of deuterium-tritium (DT) 14-MeV neutrons at the University of Michigan by Arthur Ruhlig.⁴ This experiment had a critical role in inspiring early thermonuclear fusion research directions. This article presents some unique insights from the extensive holdings within Los Alamos National Laboratory’s archives—including sources typically unavailable to a broad audience.

Steven Arndt
president@ans.org

Anyone who has heard me speak about the American Nuclear Society recently knows that I like to remind people of the ANS mission and vision statements. I invite people to read the exact words: Our mission is to “advance, foster, and spur the development and application of nuclear science, engineering, and technology to benefit society”; our vision is to see “nuclear technology . . . embraced for its vital contributions to improving peoples’ lives and preserving our planet.”

The meaning behind these statements is that ANS is here to help the profession save the world. I take that seriously: We are here to save the world. This month, Nuclear News is focusing on nuclear science, engineering, and technology’s role in space exploration both now and in the future. When we look at our mission, this is very fitting. The use of nuclear power systems in space goes back almost to the start of ANS. In 1961, the Transit 4A satellite became the first U.S. spacecraft to be powered by a radioisotope thermoelectric generator (RTG). Combined with solar cells, RTGs have been used on the Moon and on satellites and to explore the solar system and beyond. One of the interesting things about these power sources is that they were used to provide both provide electricity and heat to keep the systems they were supporting from freezing. Since then, additional nuclear systems have been designed and developed—including fission power reactors and nuclear thermal propulsion—that will provide significantly more power and faster space journeys.

Lisa D. May

Mikaela Blood

Sara M. Sanders

At the advent of space nuclear power in the 1960s, the combination of fundamental nuclear principles and first-of-its-kind spacecraft technology were the largest barriers to entry. In the modern era, however, nuclear power production and space technology have matured industries and no longer present major challenges. These days, the biggest hurdles are advanced flexible technology development, regulations and policy, and public perception, and these issues must be successfully navigated to clear the way for a nuclear future in space.

In this article, we will explore prior NASA programs that incorporated fission technology for space exploration purposes. We also will look at current programs that incorporate fission technology for deep space missions, including missions to the Moon and Mars.

Miguel Alessandro Lopez

At the University of Rhode Island, I initially enrolled as a candidate for an accelerated track to earn bachelor’s and master’s degrees in mechanical engineering, with a minor in nuclear engineering. My objective was to concentrate on reactor power design and join efforts to make nuclear energy safer, more efficient, and less stigmatized.

My plans changed after I attended a guest presentation on high-performance nuclear thermal propulsion (HP-NTP) led by Michael Houts, manager of NASA Nuclear Research at Marshall Space Flight Center. He posted his email address on one of the last slides, so I took a chance and contacted him about potential research opportunities and thesis work. As it turned out, that one little email ultimately led to four NASA-sponsored design projects at URI—two are complete, and two are in progress—as well as my thesis. My research has been on HP-NTP, specifically the centrifugal nuclear thermal rocket (CNTR) design. In that design, liquid uranium is heated to extremely high temperatures in a cylinder that is rotated between 5,000 and 7,000 revolutions per minute as liquid hydrogen passes through the center of the cylinder, where it is heated and expanded, exiting as a propellant while the liquid uranium is retained by centrifugal force.

The United States and Canadian nuclear industries used to be an example of how two independent teams of engineers facing an identical problem—making electricity from uranium—could come up with completely different answers. In the 1950s, Canada began designing a reactor with tubes, heavy water, and natural uranium, while in the U.S. it was big pots of light water and enriched uranium.

But 80 years later, there is a remarkable convergence. The North American push for a new generation of nuclear reactors, mostly small modular reactors (SMRs), is becoming binational, with U.S. and Canadian companies seeking markets and regulatory certification on both sides of the border and in many cases sourcing key components in the other country.

The challenges of climate change are bringing nuclear energy back into focus. Even in Germany, which decided on a general nuclear phaseout in 2011 as a response to the Fukushima disaster that year, nuclear energy is again being discussed as a bridging technology. Compared with fossil fuels, nuclear saves considerable greenhouse gases. However, for a holistic view of CO₂ emissions from power plants, the procurement, maintenance, and repair of plant components must also be considered. At the very least, the CO₂ emissions caused by the high costs of testing and maintaining a nuclear power plant can be reduced.

Since its formation in 2005, the United Kingdom’s Nuclear Decommissioning Authority (NDA) has been tasked with ensuring that the U.K.’s nuclear legacy sites are decommissioned and cleaned up safely, securely, cost-effectively, and in ways that protect the people and the environment.

The development of human society and technology is closely correlated to the means of energy acquisition, utilization method, efficiency, and spectrum of applications. High quality of life and sustainable socioeconomic development require a sustainable and reliable energy supply. Wealth, health, food, water, infrastructure, education, and even life expectancy itself strongly correlate with the consumption of energy per capita. Having an adequate, reliable, affordable, eco-friendly, and sustainable supply of energy is becoming more crucial for economic development and improving human well-being.

The rapid changes in the nuclear energy industry over the last decade, driven in part by fluctuating energy market prices and an aging fleet of reactors, have led to the closure of multiple reactors in the United States and other countries. These closures have increased the need for larger and more efficient ways to manage low-level radioactive waste processing and transport capacities. The safe transport of radioactive material is a key component of the overall nuclear industry reliability. Though sometimes perceived as a bottleneck and costly, it is necessary to send waste material to disposal.

Most people probably don’t think about nuclear power in terms of religion, but the association may not be so far-fetched, as suggested by a resolution adopted by the 185th Convention of the Episcopal Diocese of Chicago. “Supporting a Clean Energy Future” was passed on November 19, 2022, with 78 percent of participants voting affirmatively.