ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Nuclear Criticality Safety
NCSD provides communication among nuclear criticality safety professionals through the development of standards, the evolution of training methods and materials, the presentation of technical data and procedures, and the creation of specialty publications. In these ways, the division furthers the exchange of technical information on nuclear criticality safety with the ultimate goal of promoting the safe handling of fissionable materials outside reactors.
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!
Latest Magazine Issues
Aug 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
October 2024
Nuclear Technology
Fusion Science and Technology
August 2024
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.
S. Iijima
Nuclear Science and Engineering | Volume 17 | Number 1 | September 1963 | Pages 42-46
Technical Paper | doi.org/10.13182/NSE63-A17208
Articles are hosted by Taylor and Francis Online.
The origin of the so-called resonance disadvantage factor was investigated from the point of view of (1) the incomplete recovery of the flux at off-resonance energies and (2) the decrease in the surface flux due to the failure of the narrow resonance approximation in the moderator. The flux recovery was studied by age theory for a typical rectangular lattice of the uranium in graphite and the effect upon the absorption by the 6.7-ev resonance of U238 was found to be of the order of magnitude of 2% or less. The second problem was studied by solving for the space-energy flux by iteration. Sizeable corrections were found to be necessary for the low-lying resonances of U238 in graphite. An approximate analytical formula was presented for this correction.
