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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
2024 ANS Winter Conference and Expo
November 17–21, 2024
Orlando, FL|Renaissance Orlando at SeaWorld
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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Latest News
New laws offer nuclear industry incentives for existing power plant uprates
This year, the U.S. nuclear industry received a much-needed economic boost that could help preserve operating nuclear power plants and incentivize upgrades that extend their lifespan and power output.
Signed into law in 2022, the Inflation Reduction Act offers production tax credits (PTCs) for existing nuclear power plants and either PTCs or investment tax credits (ITCs) for new carbon-free generation. These credits could make power uprates—increasing the maximum power level at which a commercial plant may operate—a much more appealing option for utilities.
Alain Hébert
Nuclear Science and Engineering | Volume 151 | Number 1 | September 2005 | Pages 1-24
Technical Paper | doi.org/10.13182/NSE151-1-24
Articles are hosted by Taylor and Francis Online.
Improvement of the lattice code component related to resonance self-shielding calculations is described. The proposed self-shielding model is based on a subgroup flux equation with probability tables, as implemented in the CALENDF approach of P. Ribon. A new type of correlated two-dimensional probability table is introduced for the representation of the slowing-down effect in the resolved energy domain. The resulting formalism makes possible a better representation of distributed self-shielding effects.A new numerical scheme is also proposed to represent the mutual shielding effect of overlapping resonances between different isotopes in the context of the Ribon subgroup equations. The interference effects between two resonant isotopes are represented by a correlated weight matrix also computed using a CALENDF approach. The model was designed with the primary goal of allowing the straightforward replacement of legacy self-shielding components in typical lattice codes to gain improved accuracy without any noticeable increase in CPU resources.Finally, a validation is presented where the absorption rates are compared with exact values obtained using a fine-group elastic slowing-down calculation in the resolved energy domain. Other results, relative to Rowland's pin-cell benchmarks, are also presented. The need to represent mutual shielding effects, at least for mixed-oxide fuel is demonstrated.