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Aerospace Nuclear Science & Technology
Organized to promote the advancement of knowledge in the use of nuclear science and technologies in the aerospace application. Specialized nuclear-based technologies and applications are needed to advance the state-of-the-art in aerospace design, engineering and operations to explore planetary bodies in our solar system and beyond, plus enhance the safety of air travel, especially high speed air travel. Areas of interest will include but are not limited to the creation of nuclear-based power and propulsion systems, multifunctional materials to protect humans and electronic components from atmospheric, space, and nuclear power system radiation, human factor strategies for the safety and reliable operation of nuclear power and propulsion plants by non-specialized personnel and more.
Meeting Spotlight
2025 ANS Annual Conference
June 15–18, 2025
Chicago, IL|Chicago Marriott Downtown
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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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Latest News
Hanford proposes “decoupled” approach to remediating former chem lab
Working with the Environmental Protection Agency, the Department of Energy has revised its planned approach to remediating contaminated soil underneath the Chemical Materials Engineering Laboratory (commonly known as the 324 Building) at the Hanford Site in Washington state. The soil, which has been designated the 300-296 waste site, became contaminated as the result of a spill of highly radioactive material in the mid-1980s.
Emeline Rosier, Li Mao, Richard Sanchez, Luiz Leal, Igor Zmijarevic
Nuclear Science and Engineering | Volume 199 | Number 1 | April 2025 | Pages S121-S134
Research Article | doi.org/10.1080/00295639.2024.2340143
Articles are hosted by Taylor and Francis Online.
The legacy subgroup method of the APOLLO3® code, denoted the SG-GR-383g method in this paper, relies on the fine structure equation solved by the means of the General Resonance model and of the mathematical probability tables (MPTs) that are computed on the fly for the resonant mixture. Because of the use of these MPTs, a fine energy structure of 383 groups has to be employed.
In our recent work, with the intention of decreasing computational time, a subgroup method adapted to coarse-group calculations has been implemented in APOLLO3. It is based on the use of physical probability tables (PPTs), taking into account the mixture treatment, and on the Intermediate Resonance model to derive the subgroup equations, as well as the application of the Superhomogenization correction to ensure the preservation of the reaction rates in a multigroup calculation. This method, denoted SG-IR-69g in this paper, uses a 69-coarse-group energy mesh. This paper presents a comparison of the SG-IR-69g method with the legacy SG-GR-383g method, taking as reference the continuous-energy Monte Carlo TRIPOLI-4® calculations on test cases of 3 × 3 pin cells, with a central cell being either a water hole or a Gd-UO2 pin cell surrounded by UO2 pin cells. Similar accuracy on the multiplication factor was obtained for both the SG-GR-383g and SG-IR-69g methods, although more error compensations were found in the multigroup reaction rates of the latter. Even though the calculation of PPTs is more expensive than that of the mathematical ones, overall the SG-IR-69g method is more time efficient thanks to the decrease in the number of energy groups.
