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
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
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.”
D. Kontogeorgakos, I. E. Stamatelatos
Nuclear Technology | Volume 170 | Number 3 | June 2010 | Pages 460-464
Technical Note | Fission Reactors | doi.org/10.13182/NT10-A10331
Articles are hosted by Taylor and Francis Online.
The aim of this study was to validate a Monte Carlo-based model of the Greek Research Reactor-1 (GRR-1) developed with the MCNP5 code. The GRR-1 core was modeled in detail using the exact geometry without approximations. The inventory of the core was derived using the WIMS-ANL code, taking into account the different 235U burnup of each fuel assembly. The model was validated against experimentally determined control rod reactivity worth and neutron flux measurements performed in various irradiation positions. The ratio of the calculated-to-measured integral reactivity of each of the five control rods was found to be 0.972 ± 0.151, 1.083 ± 0.168, 1.156 ± 0.179, 0.874 ± 0.137, and 1.097 ± 0.170. The calculated-to-measured thermal neutron flux ratios ranged from 0.83 ± 0.04 to 1.22 ± 0.07. Therefore, good agreement between MCNP calculated and experimental values was observed. The GRR-1 core model will be fully implemented in the design of material irradiation experiments along with reactor safety and fuel management studies.
