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
Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
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.
A. K. Ghatak and S. Pearlstein
Nuclear Science and Engineering | Volume 22 | Number 2 | June 1965 | Pages 182-190
Technical Paper | doi.org/10.13182/NSE65-A20237
Articles are hosted by Taylor and Francis Online.
A numerical experiment of the transient neutron behavior following a source burst has been performed. The time-dependent Boltzmann equation (in the diffusion approximation without delayed neutrons) was propagated in time until asymptotic conditions were reached. The explicit time, space and energy solution was programed for the IBM-7094. Space-independent calculations of defined effective multiplication factors, neutron lifetimes and decay constants were performed for hydrogenous and graphite-moderated U235 or Pu239 systems. Seventy-three velocity groups were employed to detail spectral changes that occur in the approach to equilibrium. About 20 µsec and 150 µsec, respectively, were required for the energy modes to decay in the hydrogenous and graphite systems considered. The initial response of a cadmium detector is shown to be similar in multiplying and nonmultiplying assemblies and indicates the neutron slowing-down time to the cadmium resonance. No further structure in the cadmium-detector response due to the regenerative process was noted. The space-dependent properties of bare and reflected one-dimensional slabs were also briefly studied.