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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Fusion Science and Technology
October 2025
Latest News
Empowering the next generation: ANS’s newest book focuses on careers in nuclear energy
A new career guide for the nuclear energy industry is now available: The Nuclear Empowered Workforce by Earnestine Johnson. Drawing on more than 30 years of experience across 16 nuclear facilities, Johnson offers a practical, insightful look into some of the many career paths available in commercial nuclear power. To mark the release, Johnson sat down with Nuclear News for a wide-ranging conversation about her career, her motivation for writing the book, and her advice for the next generation of nuclear professionals.
When Johnson began her career at engineering services company Stone & Webster, she entered a field still reeling from the effects of the Three Mile Island incident in 1979, nearly 15 years earlier. Her hiring cohort was the first group of new engineering graduates the company had brought on since TMI, a reflection of the industry-wide pause in nuclear construction. Her first long-term assignment—at the Millstone site in Waterford, Conn., helping resolve design issues stemming from TMI—marked the beginning of a long and varied career that spanned positions across the country.
Claudia Bogdan, Sebastian Brad, Horia Necula, Oleksandr Sirosh, Catalin Brill, Mihai Vijulie, Alin Lazar, Aleksandr Grafov
Fusion Science and Technology | Volume 80 | Number 3 | May 2024 | Pages 443-454
Research Article | doi.org/10.1080/15361055.2023.2259238
Articles are hosted by Taylor and Francis Online.
The following properties are needed to increase the efficiency of refrigeration, liquefaction, and cryogenic separation cycles: Heat exchangers must have high effectiveness doubled by high compactness; small temperature differences between incoming and outgoing flows must be ensured to increase efficiency; there must be a large heat transfer surface, relative to the volume of the heat exchanger, to minimize heat loss; there must be a high heat transfer rate to reduce the transfer area; there must be a small pressure drop to reduce compression costs; and there must be high reliability with minimal maintenance. All these properties are entirely fulfilled by the designed matrix heat exchangers (MHEs). This paper presents the results of the research program developed by the team of the Cryogenic Laboratory from INC-DTCI ICSI Ramnicu Valcea, which included procedural stages of the realization and preliminary results of the characterization of the MHE-type heat exchanger in a narrow range of values to achieve a proper solution for a heat exchanger to be used for cryogenic purposes, such as cooling the gas mixture at the entrance of a distillation column of hydrogen isotopes and running at low pressure (typically regimes of 0.5 to 2.0 bars) and flows. Within several experimental campaigns, different assembly and testing techniques of the matrix heat exchanger (MHE) prototype were performed to achieve numerical data for the temperature and pressure drops along the heat exchanger and to verify ANSYS Fluent numerical simulation results. The results showed that for the designed and tested MHE prototype, a temperature drop of up to almost 230 K can be obtained at the established parameters correlated with pressure losses within a few millibars (the maximum recorded pressure drop is 80 mbars), small dimensions (64 mm high), and accessible weight (up to 2000 g).