ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
Standards Program
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!
Latest Magazine Issues
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
July 2025
Nuclear Technology
June 2025
Fusion Science and Technology
Latest News
ANS announces 2025 Presidential Citations
One of the privileges of being president of the American Nuclear Society is awarding Presidential Citations to individuals who have demonstrated outstanding effort in some manner for the benefit of ANS or the nuclear community at large. Citations are conferred twice each year, at the Annual and Winter Meetings.
ANS President Lisa Marshall has named this season’s recipients, who will receive recognition at the upcoming Annual Conference in Chicago during the Special Session on Tuesday, June 17.
David L. Luxat, Jeff R. Gabor, Richard M. Wachowiak, Rosa L. Yang
Nuclear Technology | Volume 196 | Number 3 | December 2016 | Pages 698-711
Technical Paper | doi.org/10.13182/NT16-56
Articles are hosted by Taylor and Francis Online.
The study presented in this paper summarizes work conducted as part of the Electric Power Research Institute (EPRI) Fukushima Technical Evaluation project. This effort was designed to develop a representation of the core damage events that occurred at Fukushima Daiichi Units 1, 2, and 3 using the analytical capabilities provided by the EPRI Modular Accident Analysis Program, Version 5 (MAAP5). The analytical investigations of Fukushima Daiichi performed with MAAP5 indicate that core-melt progressions at Units 1, 2, and 3 likely span a range of core damage conditions. The core status at Unit 1 is likely consistent with a large fraction of core debris having relocated into the containment. By contrast, the MAAP5 evaluations indicate that there is a reasonable potential for a significant fraction of core debris to be retained inside the reactor pressure vessel (RPV) at Unit 2. The corresponding Unit 3 simulations, however, highlight the important role that degraded high-pressure coolant injection at low RPV pressure may have played in promoting some relocation of core debris out of the RPV and into containment. The detailed containment evaluations conducted as part of this study also highlight the critical role played by thermal stratification phenomena (either in the suppression pool or in the drywell) in influencing the magnitude of containment pressure and thermal challenges. These simulations highlight the potentially critical role that thermal stratification in the upper drywell may have played in accelerating the onset of leakage through the drywell head flange due to thermal degradation of the drywell head gasket. Finally, these simulations provide good representations of the occurrence of flammable conditions in the Units 1 and 3 reactor buildings, supporting the nature and timing of the observed reactor building combustion events.