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
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Sheng Zhang, Hsun-Chia Lin, Xiaodong Sun
Nuclear Science and Engineering | Volume 197 | Number 5 | May 2023 | Pages 920-946
Technical Paper | doi.org/10.1080/00295639.2022.2102389
Articles are hosted by Taylor and Francis Online.
Molten salt reactors (MSRs) are a class of Generation IV nuclear reactors using molten salts as heat transfer fluids. MSRs bring a number of benefits, including low primary system working pressure, high working temperature, and enhanced safety due to the passive safety systems adopted. Although MSRs promise these benefits, a number of key technology needs, such as the accurate prediction of the thermal-hydraulic performance of the passive safety systems, which completely rely on natural circulation, are indispensable for MSR development, licensing, and future deployment. Therefore, this study develops the one-dimensional (1D) NAtural Circulation COde (NACCO) considering the buoyancy and radiative heat transfer effects in high-temperature molten salts for such predictions. The 1D code, developed using MATLAB, is then benchmarked with experimental data from three natural circulation flow experiments, where water, nitrate salt NaNO3-KNO3 (60–40 wt%), and fluoride salt LiF-BeF2 (66–34 mol%, FLiBe) were used as the working fluids. Our analysis shows that (1) the buoyancy and radiative heat transfer effects need to be considered for high-temperature molten salt natural circulation flows, while the radiative heat transfer effect is negligible for low-temperature water flows in the natural circulation experiments investigated, and (2) the 1D code NACCO predicts salt temperature profiles reasonably well, with less than 18°C and 25°C discrepancies from experimental data for the pipe centerline temperature of NaNO3-KNO3 and FLiBe up to 450°C and 750°C, respectively.