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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
Kiyoshi Takeuchi, Shun-ichi Tanaka
Nuclear Science and Engineering | Volume 87 | Number 4 | August 1984 | Pages 478-489
Technical Note | doi.org/10.13182/NSE84-A18514
Articles are hosted by Taylor and Francis Online.
Gamma-ray exposure buildup factors are calculated using a discrete ordinates direct integration code, PALLAS-PL, SP-Br, for water, concrete, iron, and lead, typifying materials of low, medium, and high atomic number. The radiation sources considered were both plane, at normal incidence, and at plane-isotropic. These data include the effects of secondary photon sources arising from Compton scattering, bremsstrahlung, and annihilation. Inclusion of a bremsstrahlung source influences the exposure buildup factors for high-energy photons in materials of high atomic number. The calculational accuracy is verified by comparing the PALLAS calculations with the results of experiments with both the energy spectrum and the attenuation dose transmitted through lead where the source is a plane isotropically incident 6.2-MeV gamma ray or a plane normally incident ∼8-MeV gamma ray. Comparisons are also made with other calculations of exposure buildup factors in water for a 0.5- and a 3.0-MeV plane normally incident source. The calculated buildup factors in each material are tabulated for incident energies of 0.1 to 15 MeV (except for lead where the lower energy is 0.4 MeV) and for penetration depths as great as 40 mfp.