The development of modern nuclear reactor technologies relies heavily on complex software codes and computer simulations to support the design, construction, and testing of physical hardware systems. These tools allow for rigorous testing of theory and thorough verification of design under various use or transient power scenarios.

If you head west out of Idaho Falls on U.S. Highway 20 and make your way across the Snake River Plain, it won’t be long before you’ll notice a silver dome in the distance to the north. One of the most recognizable structures in the history of nuclear energy, Experimental Breeder Reactor-II stands out from the desert landscape. The 890-square-mile site on which EBR-II is located is the former National Reactor Testing Station, now known as Idaho National Laboratory.

Nuclear thermal hydraulics—for light water reactors or advanced reactors cooled by gas, metal, or salt—is all about defining safety and performance margins as things heat up.

Nuclear research reactors throughout the world enable crucial scientific progress that benefit many sectors, health care and the environment among them. But some of those reactors need an important adjustment: a conversion from using high-enriched uranium fuel to using low-enriched uranium fuel.

Take note! Registration closes today for the U.S. Department of Energy Conference for Newcomers: Understanding Exports of Advanced Reactor Technologies, scheduled for July 26–27 at Argonne National Laboratory in Lemont, Ill.

Contact Mercedes Trent (mercedes.trent@nnsa.doe.gov) to sign up for the conference. Additional information will follow upon registration.

The Gateway for Accelerated Innovation in Nuclear (GAIN) announced June 26 the companies that have received GAIN Nuclear Energy Vouchers, which allow private companies to access the expertise and research capabilities of Department of Energy national laboratories to advance their projects toward commercial deployment. This is the third round of GAIN vouchers awarded for fiscal year 2023; the first round was announced in December 2022 and the second in March.

On the eve of the 80th anniversary of the first controlled nuclear chain reaction, Nuclear Newswire is back with the second of three prepared #ThrowbackThursday posts of CP-1 coverage from past issues of Nuclear News.

On November 17, we surveyed the events of 1942 leading up to the construction of Chicago Pile-1, an assemblage of graphite bricks and uranium “pseudospheres” used to achieve and control a self-sustaining fission reaction on December 2, 1942, inside a squash court at the University of Chicago’s Stagg Field.

Today we’ll pick up where we left off, as construction of CP-1 began on November 16, 1942.

Advanced reactors and small modular reactors with strikingly different coolants and sizes offer an array of different benefits, but when it comes to fuel cycle issues, including spent fuel and waste, they have a lot in common with conventional light water reactors. Two reports released within the last week—a National Academies of Sciences, Engineering, and Medicine (NASEM) consensus committee report two years in the making and a Department of Energy study released by Argonne National Laboratory—address the timely topic of advanced reactor fuel cycle issues. While the NASEM committee ventured to define research and infrastructure needs to support the entire nuclear power fuel cycle, inclusive of new technologies, for decades to come, the DOE report compares the front- and back-end fuel cycle metrics of three reactor designs (from NuScale Power, TerraPower, and X-energy) that have been selected for DOE cost-share–funded demonstrations within this decade. Together, these reports provide assurance that the fuel cycle needs of a fleet of new reactors can be met and point to near-term research and planning needs.

As we approach the 80th anniversary of controlled nuclear fission, Nuclear Newswire is prepared to deliver not one but three #ThrowbackThursday posts of CP-1 highlights unearthed from past issues of Nuclear News.

ANS was founded in 1954, nearly 12 years after the first controlled nuclear chain reaction was achieved on December 2, 1942, inside a pile of graphite and uranium assembled on a squash court at the University of Chicago’s Stagg Field. By 1962, ANS was prepared to “salute the 20th anniversary of the first chain reaction” at their Winter Meeting, displaying a model of Chicago Pile-1 and presenting a specially cast medal to Walter Zinn, a representative of Enrico Fermi’s scientific team. Over the years, ANS has continued to mark significant anniversaries of CP-1 at national meetings and in NN.

LA GRANGE PARK, Illinois – Idaho National Laboratory’s crucial Versatile Test Reactor (VTR) project is the focus of a newly released special issue of Nuclear Science and Engineering, the first and oldest peer-reviewed journal in its field. This special issue of the American Nuclear Society’s flagship journal presents a current snapshot of the nuclear innovation project at INL, which is being developed in partnership among six national labs and a host of industry and university partners.

It’s 1976, and you’re watching TV when a public service announcement from the American Nuclear Society airs, showing the earth being squeezed dry of its last drops of oil by a giant hand as it urges more “safe, reliable, and economical” nuclear power plants. The narrator’s last words, intoned over a fading sunset, still ring true today: “Our world is hungry for energy, and we must move ahead to preserve our future. If we don’t, we could find ourselves in the dark ages of the seventies.”

On the road to achieving net-zero by midcentury, low- or no-carbon energy sources that slash carbon dioxide emissions are critical weapons. Nevertheless, the role of nuclear energy—the single largest source of carbon-free electricity—remains uncertain.

Nuclear energy, which provides 20 percent of the electricity in the United States, has been a constant, reliable, carbon-free source for nearly 50 years. But our fleet of nuclear reactors is aging, with more than half of the 92 operating reactors across 29 states at or over 40 years old—the length of the original operating licenses issued to the power plants. While some reactors have been retired prematurely, there are two options for those that remain: retire them or renew their license.

The Thermal Hydraulic Experimental Test Article (THETA) at Argonne National Laboratory is now operating and providing data that could support the licensing of liquid-metal fast reactor designs by validating thermal-hydraulic and safety analysis codes. The new equipment has been installed in Argonne’s Mechanisms Engineering Test Loop (METL), and its first experiments are supporting data validation needs of Oklo, Inc., by simulating normal operating conditions as well as protected and unprotected loss-of-flow accidents in a sodium-cooled fast reactor.

Rempe

The Nuclear Regulatory Commission’s Advisory Committee on Reactor Safeguards has elected Joy Rempe as chair, Walter Kirchner as vice chair, and David Petti as member-at-large. All three are ANS members.

“I am honored that my colleagues on the ACRS elected me to this position,” said Rempe, of Rempe and Associates. “The leadership team looks forward to ensuring that the ACRS continues its tradition of providing the commission advice on safety issues.”

Bios: Rempe has more than 35 years of experience in the areas of reactor safety and instrumentation performance. Prior to retiring as a Laboratory Fellow at Idaho National Laboratory, she founded an instrumentation development and deployment laboratory, which supported irradiation testing in U.S. and international facilities.

The Department of Energy is dedicating $2 million to the establishment of a first-of-its-kind program to train undergraduate and graduate students in isotope research and development, production, and processing. Texas A&M University will serve as the Isotope Traineeship Coordination (ITC) site, collaborating with a team of 14 colleges and universities and three national laboratories: Argonne National Laboratory, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory.

Hart

A recent podcast style conversation on YouTube spotlights the journey of J’Tia Hart, an ANS member with an uncommon and inspiring story. The video is part of the Argonne Voices series, an oral history project recording the stories of the people behind the science at the Department of Energy’s Argonne National Laboratory. This year is Argonne’s 75th anniversary.

Background: Hart, who recently moved from Argonne to the DOE’s Idaho National Laboratory, is a nuclear engineer and was the program initiator for Argonne’s Women in Science and Technology–also known as WIST–one of the lab’s employee resource groups.

Hart’s friend Amanda Joyce interviewed Hart in the YouTube post. Joyce is a cybersecurity expert who runs the DOE’s annual CyberForce Competition.

Companies, universities, and national laboratories across the United States are working together to develop and demonstrate advanced nuclear technologies. To deploy those technologies on a global scale and maximize U.S. efforts to combat climate change, technology developers eyeing the export market must navigate rules and recommendations designed to ensure that international safeguards, security, and nonproliferation standards are met. Understanding and, where appropriate, integrating these standards early in the development process is crucial for streamlining export and technology deployment.

At the box office or streaming at home, it’s fear, not truth, that sells. The laws of physics are swept aside, apocalypse is inevitable, and superpowered heroes wait until the last possible second to save the universe. It can make for great entertainment, but in the real world we need to stick with science over science fiction and be wowed by engineering, not special effects.

The truth is, science and innovation are incredible in their own right. From communications and machine learning to space travel and medical advances, technology is evolving in hyperdrive to solve real problems. With climate change and global warming here on earth, we don’t have to go looking for trouble in a galaxy far, far away.

The Department of Energy announced in 2020 its approval of Critical Decision 1 for the Versatile Test Reactor (VTR) project, a one-of-a-kind scientific user facility that would support research and development of innovative nuclear energy and other technologies. The decision was well received by the nuclear energy community—after all, the DOE’s Nuclear Energy Advisory Committee had studied and reported on the need for the VTR and found strong support for the project among reactor developers, federal agencies and national laboratories, and university researchers.

Coolant flow around the fuel pins in a light water reactor core plays a critical role in determining the reactor’s performance. For yet-to-be-built small modular reactors, a thorough understanding of coolant flow will be key to successfully designing, building, and licensing first-of-a-kind reactors.