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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.
Hoai Nam Tran, Yasuyoshi Kato, Yasushi Muto
Nuclear Science and Engineering | Volume 158 | Number 3 | March 2008 | Pages 264-271
Technical Paper | doi.org/10.13182/NSE08-A2752
Articles are hosted by Taylor and Francis Online.
A burnable poison (BP) loading principle has been proposed for once-through-then-out refueling of a high-temperature gas-cooled reactor (HTGR) core with pebble fuel. The principle holds that an axial core power peaking factor can be minimized when k of the fuel pebbles is kept constant during their axial movement from the top to the bottom of the core by adding BP. This principle has been confirmed numerically using B4C with 10B enrichment of 90% and Gd2O3 with natural content as BP. Spherical particles of B4C and Gd2O3 are distributed uniformly in the fuel pebble. The respective optimal radius and number of BP particles are 90 m and 1650 for B4C and 950 m and 16 for Gd2O3. Through addition of B4C and Gd2O3, the power peaking factors are reduced from 4.4 to 1.61 and 1.64, respectively. Burnup reactivity swings are reduced from 38% to about 2% in both BP loadings. Because of reduction of the power peaking factors, the maximum fuel temperatures are respectively lower than the maximum permissible values of 1250 and 1600°C for normal operation and depressurization accident.
