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Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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.”
Tran Kim Tuyet, Alexis Jinaphanh, Cédric Jouanne, Frédéric Gérardin, Sébastien Lemaire, Andrea Zoia
Nuclear Science and Engineering | Volume 198 | Number 2 | February 2024 | Pages 319-335
Research Article | doi.org/10.1080/00295639.2023.2195925
Articles are hosted by Taylor and Francis Online.
In view of their key role in radiation shielding and nuclear instrumentation applications, photonuclear reactions are receiving growing attention. In this work, we compare the results of the Monte Carlo codes TRIPOLI4®, DIANE, and MCNP® with respect to the Barber and George (B&G) benchmark, with the aim of assessing the accuracy of both nuclear data and particle transport codes for the simulation of photonuclear reactions. We compute the photoneutron yield resulting from the Bremsstrahlung radiation induced by a monoenergetic electron beam (10.5 to 35.5 MeV) impinging on C, Al, Cu, Pb, Ta, and U material targets. The simulation specifications closely follow those of the B&G experiment. For all codes, the reference nuclear data libraries are ENDF/B-VII.1 for neutron transport and photonuclear reactions and EPDL97/EEDL97 for photon/electron transport. Comparisons of the simulation results show an overall agreement between the codes and experimental data and in-between codes, despite some discrepancies.
In order to investigate these effects, we performed a sensitivity analysis by tallying the photon production in addition to neutron production by replacing the electron source with a pure photon source (to single out the impact of electron transport) and by replacing the ENDF/B-VII.1 library with the IAEA/PD-2019. The major contribution to the observed discrepancies is found to be related to the electromagnetic shower models used for coupled electron-photon transport in Monte Carlo codes.