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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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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.”
Behrooz Khorsandi, Mehdi Reisi Fard, Thomas E. Blue, Don W. Miller, Wolfgang Windl
Nuclear Technology | Volume 159 | Number 2 | August 2007 | Pages 208-220
Technical Paper | Radiation Measurements and Instrumentation | doi.org/10.13182/NT07-A3866
Articles are hosted by Taylor and Francis Online.
Focusing on the gas turbine-modular helium reactor (GT-MHR), we have developed methods to predict the positions in a nuclear reactor where silicon carbide (SiC) semiconductor diode detectors may work functionally as neutron monitors for at least one refueling cycle. Using MCNP and TRIM, we determined the count rate due to fast neutron-induced primary knock-on atoms and tritons, and the number of displacement damage defects that are created per count and over a refueling cycle, for SiC diode detectors placed at four different radial locations in the central reflector of the GT-MHR. We found that although the total count rates for the SiC detectors placed in locations close to the fuel elements were highest (~1.2 × 106 counts/s), at those locations the detectors cannot tolerate the damage caused by fast neutrons for a reactor refueling cycle. On the contrary, for SiC detectors placed at the center of the central reflector, where the thermal neutron flux is the dominant flux component, the detectors can survive a GT-MHR refueling cycle. At this location, the total count rate for the SiC diode detectors that we have analyzed is ~1.6 × 105 counts/s.