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.”
W. F. G. van Rooijen
Nuclear Science and Engineering | Volume 162 | Number 3 | July 2009 | Pages 299-306
Technical Note | doi.org/10.13182/NSE162-299
Articles are hosted by Taylor and Francis Online.
The purpose of this technical note is to introduce a definition for breeding gain and other performance parameters for nuclear reactors and their associated fuel cycle. The newly proposed performance parameters have a more general nature than expressions currently in common use. Since the performance parameters require a weighting scheme, which expresses how individual isotopes contribute to the overall fuel cycle performance (breeding, transmutation, or otherwise) of the reactor, expressions are derived for the isotope weight factors. In this technical note, weighting schemes are introduced for a breeding fuel cycle and a transmutation fuel cycle, and the proposed definitions are applied to specific example calculations of a pressurized water reactor mixed oxide irradiation, a breeder reactor cycle, and a transmutation reactor cycle. It will be shown by an example that a net destruction of transuranic material will not always lead to a reduction of the decay heat released from the spent nuclear fuel. This effect is due to the buildup during irradiation of isotopes with a high decay heat release. With the general performance parameters defined in the present work, it is possible to more fully characterize (advanced) nuclear fuel cycles, incorporating long-term radioactivity in a straightforward manner.