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Division Spotlight
Operations & Power
Members focus on the dissemination of knowledge and information in the area of power reactors with particular application to the production of electric power and process heat. The division sponsors meetings on the coverage of applied nuclear science and engineering as related to power plants, non-power reactors, and other nuclear facilities. It encourages and assists with the dissemination of knowledge pertinent to the safe and efficient operation of nuclear facilities through professional staff development, information exchange, and supporting the generation of viable solutions to current issues.
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.
Larry R. Foulke, Elias P. Gyftopoulos
Nuclear Science and Engineering | Volume 30 | Number 3 | December 1967 | Pages 419-435
Technical Paper | doi.org/10.13182/NSE67-A18402
Articles are hosted by Taylor and Francis Online.
A space-dependent reactor kinetics approximation, called the Natural Mode Approximation (NMA), has been applied to the calculation and interpretation of reactor dynamic experiments. The NMA is based on a modal expansion technique where the space- and time-dependent reactor variables are approximated by a series of products of time-dependent coefficients and space-dependent expansion modes. The modes are the eigenvectors of a linear operator derived from the complete set of equations describing the reactor system at an initial reference condition. A pair of computer codes, MUDMO-II and SYNSIG, are used to synthesize approximate modes in two-dimensional systems without feedback. An oscillation test is proposed which may be used to verify key parameters of the NMA. The experimental technique is described and applied to both numerical and actual measurements. In addition, it is shown how a natural mode expansion may be used to interpret standard dynamic experiments when the observations are functions of space and time. The results of calculations of kinetic problems are compared with those of independent calculations which are considered to be exact. Good agreement is established. It is shown that the flux tilting following a localized perturbation is a sensitive function of the relative magnitudes of the measurable parameters of the NMA. The novel idea of “correction modes” is introduced which increases the accuracy of a low-order NMA without appreciable increase in computation time.