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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.
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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!
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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.”
N. J. Peters, K. Kutikkad
Nuclear Technology | Volume 201 | Number 1 | January 2018 | Pages 80-98
Technical Paper | doi.org/10.1080/00295450.2017.1398582
Articles are hosted by Taylor and Francis Online.
The details of robust computational and novel semiempirical methodologies that were developed and tested at the University of Missouri Research Reactor (MURR) to accurately determine the possibility of a “hot” startup and the estimated critical position (ECP) of the control rods following an unplanned shutdown are presented. The computations, based on a modified coupled MCNP5-ORIGEN2 code system and using ENDF/B-VII.0 and TENDL-2013 nuclear data sets, accurately simulate the MURR core operational histories while predicting the critical rod positions within ±0.001 Δk/k of experimental critical data. In this study, using the coupled MCNP5-ORIGEN2 computations, various core-specific parameters were methodically characterized and were adapted into a semiempirical formulation better suited for practical reactor operations. The predictive capabilities of these novel semiempirical approaches regarding core criticality and ECPs required utilizing, for the first time, the net transient response of the negative reactivity worth for necessary fission product poisons including 135mXe and several others. Calculation-to-experiment deviations in hot-startup criticals and the corresponding control rod positions are shown to be less than ±0.03% Δk/k and ±1% difference in relative rod position, respectively.