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Conference Spotlight
2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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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
High temperature fission chambers engineered for AMR/SMR safety and performance
As the global energy landscape shifts towards safer, smaller, and more flexible nuclear power, Small Modular Reactors (SMRs) and Gen. IV* technologies are at the forefront of innovation. These advanced designs pose new challenges in size, efficiency, and operating environment that traditional instrumentation and control solutions aren’t always designed to handle.
Li Mao, Igor Zmijarevic, Richard Sanchez
Nuclear Science and Engineering | Volume 188 | Number 1 | October 2017 | Pages 15-32
Technical Paper | doi.org/10.1080/00295639.2017.1332890
Articles are hosted by Taylor and Francis Online.
This paper presents two resonance self-shielding methods recently implemented in APOLLO3Ⓡ for fast reactor calculations: a recently developed method, based on Tone’s method, and the subgroup method. Both methods utilize the so-called mathematical probability tables. Numerical results for a pin cell and for a sodium-cooled fast reactor assembly show that Tone’s method produces precision similar to that of the subgroup method while reducing greatly the CPU time. The results also show that utilization of the approximated multicell model in the calculation of collision probabilities noticeably decreases the CPU time as compared to the direct-integration approach, while keeping equivalent accuracy. Finally, our tests show the improvement in the fast neutron spectrum gained by using an incident-energy-dependent fission spectrum instead of the traditional average fission spectrum.