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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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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.
Yasushi Tsuboi, Kazuo Arie, Nobuyuki Ueda, Tony Grenci, A. M. Yacout
Nuclear Technology | Volume 178 | Number 2 | May 2012 | Pages 201-217
Technical Paper | Small Modular Reactors / Fission Reactors | doi.org/10.13182/NT10-74
Articles are hosted by Taylor and Francis Online.
The Super-Safe, Small and Simple (4S) sodium-cooled fast reactor plant incorporates innovative design features, such as a nonrefueling reactor, passive safety, low maintenance requirements, and inherent security. Major components such as the reflector drive mechanisms, the electromagnetic pumps, and the double-wall tube steam generator have been optimized for efficient and safe operation.The nonrefueling reactor concept is made possible by incorporating a 30-yr refueling interval for the reflector-controlled metallic fuel core. Sodium-cooled, metallic-fueled fast reactors have a good conversion ratio due to fast neutron usage, thus extending the core life. Passive safety is achieved with redundant residual heat removal systems that function using only natural circulation, and a metallic core with a negative reactivity coefficient. Low maintenance requirements are achieved by simplifying the design and minimizing the use of active components, and by using electromagnetic pumps, which have no moving parts. The inherent security of the nuclear materials is significantly enhanced by the nonrefueling reactor concept and the minimal maintenance requirements. In addition, the reactor building is located below ground level, providing substantial protection against an aircraft impact and thus further enhancing the security of the design.The demonstration of key components such as the electromagnetic pumps and the steam generator is part of an ongoing testing program that has already confirmed many of the 4S engineering solutions.This paper describes the current status of design and component tests for the 4S reactor.