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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.
Young Min Kwon, Chan Eok Park, Jin Ho Song
Nuclear Technology | Volume 122 | Number 3 | June 1998 | Pages 295-305
Technical Paper | Thermal Hydraulics | doi.org/10.13182/NT98-A2871
Articles are hosted by Taylor and Francis Online.
To investigate the realistic behavior of mass and energy release and resultant containment response during a large-break loss-of-coolant accident (LOCA), analyses are performed on the Yonggwang (YGN) 3&4 nuclear power plants using the RELAP5/CONTEMPT4 computer code. Comparative analyses using conservative design computer codes are also performed. The break types analyzed are the double-ended guillotine breaks at the cold leg and hot leg. The design analysis predicts that the containment peak pressure occurs during the postblowdown phase for the cold-leg break. However, RELAP5/CONTEMPT4 analyses show that the containment pressure has a peak during the blowdown phase, thereafter it decreases monotonously without the postblowdown peak. For the hot-leg break, revised design analysis shows a much lower pressure than that reported in the YGN 3&4 final safety analysis report. The RELAP5/CONTEMPT4 analysis shows a similar trend and confirms that the bypass flow through the broken loop steam generator during postblowdown is negligibly small compared to that of the cold-leg break. In conclusion, realistic analysis by RELAP5/CONTEMPT4 demonstrates that the containment peak pressure occurs during the blowdown phase for both cold- and hot-leg large-break LOCAs, and there is no physical mechanism resulting in mass and energy discharge that can pressurize the containment after end of blowdown for a hot-leg break. Also, it is suggested that the substantial conservatism included in the design analysis should be improved to provide benefits in relaxing the plant technical specifications and reducing the containment design pressure.
