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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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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.
C. R. Adkins, T. E. Murley, M. W. Dyos
Nuclear Science and Engineering | Volume 36 | Number 3 | June 1969 | Pages 336-350
Technical Paper | doi.org/10.13182/NSE69-A18732
Articles are hosted by Taylor and Francis Online.
The well-known approximations used for finding multigroup cross sections and the Doppler coefficient are examined to determine their validity. The method involves comparing the approximate methods of one fast-reactor cross-section code (MC2) with a more rigorous treatment which removes most of the approximations. The unresolved resonance region makes a considerable contribution to the Doppler coefficient in fast reactors, and this region is treated more precisely by generating pseudo resonances using random sampling techniques within the Breit-Wigner single level formalism. A procedure is developed which ensures that the generated pseudo resonances are consistent with measured pointwise data. The resonance data is used in an ultra-fine energy group integral transporttheory code which treats the space-dependent slowing down problem in a very precise manner. A numerical comparison between the approximate methods used in MC2 and those used in the more rigorous calculations is made for a mixed carbide, sodium-cooled fast breeder reactor. Aside from some very significant detailed differences, it is shown that the approximations used in MC2 are not too severe, and that the code is adequate for determining the multigroup cross sections and the Doppler coefficient. The more rigorous method is a very time consuming and detailed procedure not well suited for design calculations. It is intended to serve as a standard, to which more approximate methods can be compared.