ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
Standards Program
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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Jul 2024
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Nuclear Science and Engineering
September 2024
Nuclear Technology
August 2024
Fusion Science and Technology
Latest News
Taking shape: Fusion energy ecosystems built with public-private partnerships
It’s possible to describe fusion in simple terms: heat and squeeze small atoms to get abundant clean energy. But there’s nothing simple about getting fusion ready for the grid.
Private developers, national lab and university researchers, suppliers, and end users working toward that goal are developing a range of complex technologies to reach fusion temperatures and pressures, confounded by science and technology gaps linked to plasma behavior; materials, diagnostics, and electronics for extreme environments; fuel cycle sustainability; and economics.
Jonas Berger, Alexander Mühle, Kai-Martin Haendel
Nuclear Science and Engineering | Volume 194 | Number 6 | June 2020 | Pages 415-421
Technical Paper | doi.org/10.1080/00295639.2019.1705656
Articles are hosted by Taylor and Francis Online.
During the lifetime of fuel assemblies, irradiation and fluid mechanical forces can cause a permanent deformation in the lateral direction that leads to larger interassembly water gaps in the reactor core. The standard reload safety analysis for the reactor core is developed for a uniform distribution of corewise interassembly water gaps. A nonuniform distribution of water gaps with locally larger or smaller water gaps could lead to a significant change in the positions of the hot-spot factors. Thus, such modifications could also impact boundary conditions for safety analysis or boundary conditions of the reactor core surveillance systems. To analyze the impact of a nonuniform water-gap distribution on the safety analysis and the reactor core surveillance systems, TÜV Nord EnSys is developing a new methodology that allows the incorporation of assembly bow effects in core analysis. For this methodology, functions linking the maximal relative power increase in the vicinity of the modified water gap to the fuel properties had to be derived. This was accomplished by simulating for gaps between different fuel types at selected positions in a full-core model of a generic four-loop Siemens/Kraftwerk Union pressurized water reactor using the bow model of the two-group diffusion code SIMULATE-3. The data of the maximal relative power increase were linearly correlated with the spectral indices and the coolant densities of the two gap-adjacent assemblies. Then a function was derived that provides a firsthand approximation of the maximal relative power increase using only the physical properties of the unbowed core configuration. The maximal absolute positive deviation of the function from the simulation results was 2.4%.