ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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!
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Latest News
NC State, SRNS partner to attract young talent
North Carolina State University and Savannah River Nuclear Solutions (SRNS) have joined forces to address the ongoing need for specialists in nuclear and criticality safety engineering (N&CSE) at the Department of Energy’s Savannah River Site, near Aiken, S.C.
Jesson Hutchinson, Jennifer Alwin, Alexander McSpaden, William Myers, Michael Rising, Rene Sanchez
Nuclear Technology | Volume 207 | Number 1 | December 2021 | Pages S62-S80
Technical Paper | doi.org/10.1080/00295450.2021.1908076
Articles are hosted by Taylor and Francis Online.
Criticality experiments with 235U (metal and hydride) and 239Pu (metal) were performed during the Manhattan Project. Results from these experiments provided necessary information for the success of the Manhattan Project [LA-1033 to LA-1036 (1947), LA-02532-MS V I (1961), and Critical Assembly: A Technical History of Los Alamos During the Oppenheimer Years, 1943–1945 (1993)]. These experiments have been previously described in compilations made after the Manhattan Project, but those works are either lacking in technical details or are not publicly available. This work aims to provide detailed information while showcasing the enduring impact of these experiments 75 years after they were performed. Furthermore, we use modern computational methods embodied in the MCNP6® code and ENDF data to analyze and interpret these historic measurements. The world’s first four criticality accidents are also discussed, as lessons learned from these helped shape the field of criticality experiments.