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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
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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.”
T. H. Trumbull, D. R. Harris
Nuclear Technology | Volume 154 | Number 3 | June 2006 | Pages 350-360
Technical Paper | Radiation Protection | doi.org/10.13182/NT06-A3739
Articles are hosted by Taylor and Francis Online.
The effect of material homogenization on the calculated gamma-ray dose rate was studied for several arrangements of typical pressurized water reactor (PWR) spent fuel pins in an air medium using the Monte Carlo code MCNP. The models analyzed increased in geometric complexity, beginning with a single fuel pin; progressing to small lattices, i.e., 3 × 3, 5 × 5, and 7 × 7 fuel pins; and culminating with a full 17 × 17 pin PWR bundle analysis. The fuel pin dimensions and compositions were taken directly from a previous study, and efforts were made to parallel this study by specifying identical flux-to-dose functions and gamma-ray source spectra.The analysis shows two competing components to the overall effect of material homogenization on the calculated dose rate. Homogenization of pin lattices tends to lower the effect of radiation channeling but increase the effect of source redistribution. Depending on the size of the lattice and the location of the detectors, the net effect of material homogenization on the dose rate can be insignificant, or it can range from a 6% decrease to a 35% increase relative to the detailed geometry model.
