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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.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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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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NRC engineers share their expertise at the University of Puerto Rico
Robert Roche-Rivera and Marcos Rolón-Acevedo are licensed professional engineers who work at the U.S. Nuclear Regulatory Commission. They are also alumni of the University of Puerto Rico–Mayagüez (UPRM) and have been sharing their knowledge and experience with students at their alma mater since last year, serving as adjunct professors in the university’s Department of Mechanical Engineering. During the 2023–2024 school year, they each taught two courses: Fundamentals of Nuclear Science and Engineering, and Nuclear Power Plant Engineering.
Nathan E. White, Sudarshan K. Loyalka
Nuclear Science and Engineering | Volume 181 | Number 3 | November 2015 | Pages 318-330
Technical Paper | doi.org/10.13182/NSE15-10
Articles are hosted by Taylor and Francis Online.
In high-temperature gas-cooled reactors (HTGRs), carbonaceous dust can be generated both during normal operations and during accidents. The dust particles can be highly irregular and highly porous and have very large surface areas that may make dust-facilitated (or dust-hindered) fission product (FP) transport a major factor. Since the FP interactions with dust can occur while the dust is on a surface as well as in suspension, there is a need to obtain computational and experimental results for both situations. In 2014, Smith and Loyalka used the Green's Function Method to study condensation (results for absorption/deposition and evaporation are generally directly related to the condensation problem) on chainlike particles and particle agglomerates in the diffusion regime. In 2010, Smith and Loyalka made progress in computation of evaporation/condensation particles on a surface, but again in the diffusion regime. Since the particle sizes of interest span a wide range—from nanometers to microns (10−9 m to 10−6 m)—and are also porous with small pores and pathways for FPs, these computations need to be extended to the transport regime where the particle sizes (and/or pores) are comparable to the vapor (FP) molecular mean free path (∼0.05 μm) in the gaseous phase (air or helium, or some mix thereof with other contaminants). The focus of the present paper is on Monte Carlo computation of condensation rate on chainlike particles and particle agglomerates in the transport regime using the one-speed approximation, and we report a number of new results that provide new insights and path for future explorations.