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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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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.
Faith R. Beck, Yue Jin, Fan-Bill Cheung (Penn State), Stephen M. Bajorek, Kirk Tien, Chris L. Hoxie (NRC)
Proceedings | Advances in Thermal Hydraulics 2018 | Orlando, FL, November 11-15, 2018 | Pages 739-750
In a large break loss of coolant accident (LOCA) in a pressurized water reactor (PWR), a break may occur on one of the cold legs. The emergency core cooling system (ECCS) must provide sufficient coolant to the core to remove decay heat and prevent the cladding from exceeding 1477.6 K. During reflood, flow to the core is most often gravity driven, resulting in an oscillatory delivery of coolant to the core. These oscillations are attributed to vapor generation in the core and the dynamic response of the downcomer water level. The amount of liquid entrained can be significant because in an accident scenario, the progress rate will be slowed and it can take longer to fully recover the core. Most reflood experiments have been conducted with constant forced reflood rates, and have not explored in detail the effects of oscillations on liquid entrainment and rod bundle heat transfer. The few studies that have been conducted for oscillating flows indicate enhanced entrainment of liquid at the quench front. At the NRC-PSU Rod Bundle Heat Transfer (RBHT) Test Facility, an electrically heated 7×7, 3.66m long rod bundle array has the capabilities to perform both constant and oscillatory forced flooding rate experiments. For varying oscillation periods and inlet subcoolings, these system parameters’ effect the liquid entrainment has been analyzed. Using a frequency analysis and signal processing technique, the percent liquid entrainment has been determined in one up- or down-stroke for oscillatory reflood. These findings, which are important to rod bundle heat transfer during reflood transients, have been explained based on the physics of the problem.