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Division Spotlight
Fusion Energy
This division promotes the development and timely introduction of fusion energy as a sustainable energy source with favorable economic, environmental, and safety attributes. The division cooperates with other organizations on common issues of multidisciplinary fusion science and technology, conducts professional meetings, and disseminates technical information in support of these goals. Members focus on the assessment and resolution of critical developmental issues for practical fusion energy applications.
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.
Lewi Tonks
Nuclear Science and Engineering | Volume 6 | Number 3 | September 1959 | Pages 202-213
Technical Paper | doi.org/10.13182/NSE59-A25660
Articles are hosted by Taylor and Francis Online.
A quantitative but simple theory of the control effect of a uniformly distributed set of thermal poison elements in a hydrogen-moderated bare reactor core has been developed. Starting with plane parallel poison sheets, a zero-flux boundary condition, in a slab core and applying Fourier analysis, it has been possible to generalize to any boundary condition, to orthogonally intersecting sets of poison sheets in an infinite rectangular core, to control crosses, and cylindrical rods in regular array, to finite rectangular cores, and to finite cylindrical cores. Each element of the control array is associated with a cross-sectional area Ac within the core and within this area is an easily determined effective “absorption area” C. To a rather good accuracy the critical k of the controlled core is greater than the k of the uncontrolled core by the ratio Ac/(Ac − C). In this the theoretically based conclusion substantiates the intuitionally based and empirically confirmed methods worked out by Greebler (1), and by Pearlstein, Ruane, and Storm (2), and furnishes correction terms.