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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Nuclear Science and Engineering
October 2024
Nuclear Technology
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August 2024
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.
Edward W. Larsen, R. P. Hughes
Nuclear Science and Engineering | Volume 73 | Number 3 | March 1980 | Pages 274-285
Technical Paper | doi.org/10.13182/NSE80-A19851
Articles are hosted by Taylor and Francis Online.
A general problem of time-dependent neutron transport in a spatially heterogeneous medium is analyzed by two perturbation methods that have previously been applied to specialized problems. These “buckling” and “asymptotic” methods are shown to be equivalent in the sense that the asymptotic method leads to a time-dependent diffusion equation with constant coefficients, whereas the buckling method leads to the corresponding dispersion law. Two applications, the calculation of keff, and the derivation of a point reactor model are given. Also, the general results obtained here are shown, in several special cases, to reduce to the simpler results obtained previously.