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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.
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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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. Barnard, N. A. Khan, R. C. F. Mclatchie, M. J. Poole, J. H. Tait
Nuclear Science and Engineering | Volume 17 | Number 4 | December 1963 | Pages 513-522
Technical Paper | doi.org/10.13182/NSE63-A18441
Articles are hosted by Taylor and Francis Online.
In the experiment to be described the 28 Mev electron linac at Harwell was used as a neutron source to produce 1 µsec bursts of 1011 electrons 160 times per second. A natural uranium target was placed centrally against one face of a 60 cm x 62.2 cm x 71.1 cm graphite block, and a neutron beam extracted from a channel running into the center of the block. This beam was interrupted by a slow chopper running in synchronism with the pulses from the accelerator. In this way 100 µsec “time samples” of the neutrons in the block were taken and their spectrum determined by the time-of-the-flight method. The instant of the “time sample” relative to the fast neutron pulse could be varied by an electronic delay circuit. Neutron spectra are presented for the time varying between 300 µsec and 1000 µsec after the pulse. These spectra differ from the Maxwellian shape but approach asymptotically to a “cooled Maxwellian” from which they are indistinguishable after 1000 µsec. Detailed calculations of the spectra have been made using an IBM 7090 computer to obtain a numerical solution of the time and energy dependent diffusion equation; using a scattering kernel based on the scattering measurements made at Chalk River. The experimental results are also compared with spectra using a scattering kernel based on the heavy gas model with a fictitious mass of 33.