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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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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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.
Ehsan U. Khan
Nuclear Science and Engineering | Volume 61 | Number 1 | September 1976 | Pages 112-115
Technical Note | doi.org/10.13182/NSE76-A28467
Articles are hosted by Taylor and Francis Online.
The relative importance of energy redistribution by thermal conduction and sweep flow mixing in a wire-wrapped fuel assembly are quantitatively described at various Reynolds numbers. For a given bundle geometry, a critical Reynolds number exists below which thermal conduction appears to govern the temperature distribution within the bundle. As the thermal conduction effects become progressively important at low Reynolds numbers, the transverse temperature gradient in the bundle decreases. This result would have an important effect on incoherency in assembly voiding. If one were to develop a model of a full-size liquid-metal fast breeder reactor bundle to study incoherency in voiding, an important parameter is the maximum temperature difference at the bundle exit. Whereas this parameter is the same for a 19- and 217-pin bundle at design operating conditions, it is significantly different at low Reynolds numbers. This low Reynolds number bundle-size effect was determined by analysis of steady-state data and is valid for very slow transients where the thermal inertia of the structure is unimportant. Inclusion of the structure thermal inertia would tend to diminish this bundle-size effect.