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
Fusion Science and Technology
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.
P. Goldschmidt
Nuclear Science and Engineering | Volume 49 | Number 3 | November 1972 | Pages 263-273
Technical Paper | doi.org/10.13182/NSE72-A22541
Articles are hosted by Taylor and Francis Online.
Pontryagin’s Maximum Principle and Robbins’ Criterion allow us to find, in the general case of intermediate reactors, the distribution of fuel enrichment that minimizes the critical mass of a reactor of given power and subject to constraints on the maximum power density and on the enrichment. The two group diffusion model is used in slab geometry. The optimal sequence of control (enrichment) zones is made up of a central constant power density zone, a zone of maximum enrichment, a zone of variable enrichment (where the control is singular) and finally an external zone of minimum enrichment (or a reflector). In the particular case of fast reactors the optimal solution does not include the singular control zone.