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
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.
Makoto Tsuiki, Katsutada Aoki, Sadanori Yoshimura
Nuclear Science and Engineering | Volume 64 | Number 3 | November 1977 | Pages 724-732
Technical Paper | doi.org/10.13182/NSE77-A27101
Articles are hosted by Taylor and Francis Online.
A theoretical background for the convergence of void iterations in boiling water reactor (BWR) core calculations is considered. First, the process of each void-iteration step is interpreted as a transformation in a set of vectors representing the characteristics of the core, and the condition for convergence is derived in terms of the spectral radius of the transformation operator. Second, to visualize the convergence condition, the concept of a trajectory of channel power is introduced. Third, it is explained that the spectral radius of the transformation operator can be changed by changing the number of source iterations within each void iteration step. Based on this analysis, an optimum number of source iterations, when the Chebyshev polynomial acceleration technique is employed, is estimated for a typical BWR core. Numerical examples, presenting both divergent and convergent cases, show the validity of the present theoretical analysis.