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Division Spotlight
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.
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.
E. Johansson, E. Jonsson, M. Lindberg and J. Mednis
Nuclear Science and Engineering | Volume 22 | Number 2 | June 1965 | Pages 157-170
Technical Paper | doi.org/10.13182/NSE65-A20235
Articles are hosted by Taylor and Francis Online.
A series of experimental and theoretical investigations on neutron spectra in lattice cells has been started at the reactor R1. This report gives the results from the work on the first three cells. The cells consisted of uranium tubes surrounded by D2O. They were placed in the central vertical channel of the reactor. The neutron spectra from lead scatterers in the center of the tubes were measured with a fast chopper in the energy region from 0.01 to 100 eV. The beam spectrum from the lead piece was expected to correspond to the angular flux integrated over all angles. This was tested in an accessory experiment which gave some correction factors for the tube measurements. For the calculations the THERMOS code has been used. The energy region ranged from 0.00025 to 3.06 eV. Three scattering models for deuterium have been used—the free-gas model (D mass 3.595), the effective-width model, and the Nelkin model. With all three models the THERMOS code reproduced the thermal spectra within a few percent. The effective-width model and the Nelkin model also gave reasonable agreement in the epithermal region. The free-gas model, however, gave too high a ratio between the epithermal and the thermal neutron densities. The computation time required for a 20-space, 30-energy-group calculation on an IBM-7090 computer was about 4 min.