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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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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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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.
John P. Church
Nuclear Science and Engineering | Volume 21 | Number 1 | January 1965 | Pages 49-61
Technical Paper | doi.org/10.13182/NSE65-A21015
Articles are hosted by Taylor and Francis Online.
The integral neutron-transport equation is solved for the space-dependent mono-energetic neutron density in a unit cell. By using step functions to represent the spatial dependence of the collision probabilities, one may rearrange the integro-differential transport equation in a special way such that the left-hand side contains only the leakage term and the term describing the total collision probability for the homogeneous medium of one region, k′, of the original problem. The Green's-function technique is then used to convert the integro-differential equation to an integral equation. Thus, although the resulting equation may be applied to a heterogeneous cell, the kernel of the equation depends only on the total collision probability in the particular region k′. Numerical results are presented for a two-region unit cell in slab geometry and compared with published results of DSN, PN double-PN and variational calculations. For unit cells that are of the order of two mean free paths or less in thickness, the zeroth-order spherical harmonic approximation for this method yields results comparable to very high order DSN, PN and double-PN calculations. Further, once the Green's function has been computed, additional cell calculations can be performed with relatively little additional computational effort.