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Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
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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.
Frank McGirt, Martin Becker
Nuclear Science and Engineering | Volume 39 | Number 1 | January 1970 | Pages 56-66
Technical Paper | doi.org/10.13182/NSE70-A21171
Articles are hosted by Taylor and Francis Online.
The object of this investigation is to obtain qualitative and quantitative understanding of reentrant hole (or extraction channel) effects in pulsed thermal- and fast-neutron experimental assemblies. The calculational model used assumes slab geometry for the unperturbed (without the hole) situation and considers cylindrical reentrant holes of various diameters and depths. The two-dimensional nature of the hole is represented by a wall-streaming term which is used as a boundary condition for a reduced effective slab. The effective slab geometry is obtained by reducing the thickness of the original slab by an amount equal to the depth of the reentrant hole. The validity of this important simplification is confirmed by results of two-dimensional discrete ordinates transport calculations in which the reentrant hole is introduced explicitly. A second basic assumption used to simplify the numerical calculations is that the flux along the walls of the reentrant hole is adequately represented by the unperturbed flux. This approximation is judged valid by the success of the method in predicting experimental results. The analytical procedure is applied numerically using discrete Sn transport theory. Solutions are obtained from a code system which makes use of a standard production program DTF-IV as a subroutine for performing unperturbed and perturbed effective slab calculations. The calculational model yielded good predictions of the distorted fluxes for reentrant hole experiments performed on water at Rensselaer Polytechnic Institute. For fast neutron spectra, the model predicted distortions (particularly at high energies) which were significant but not large enough to limit the viability of the experiment.