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
Mathematics & Computation
Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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.
Mohamed Sawan, Robert W. Conn
Nuclear Science and Engineering | Volume 54 | Number 2 | June 1974 | Pages 127-142
Technical Paper | doi.org/10.13182/NSE74-A23401
Articles are hosted by Taylor and Francis Online.
Methods for the analysis of neutron pulses slowing down in heavy media are presented. The Green’s function coupling method is reviewed and the application of a prompt-jump approximation to pulses slowing down in heavy media is discussed. In this paper, these methods are applied in particular to the analysis of the lead slowing down time spectrometer (LSDTS) and the application of this device to nondestructive fissile material assay (NDA). The effects of pulse width, spectrometer size, higher order spatial modes, and lead cross-section data on the calibration curve (t versus 1/√E, the dieaway curve N(t) versus t, and the time-dependent spectrum of the LSDTS are reported. For NDA, the assay of fresh light-water reactor (LWR), plutonium recycle, and fast reactor fuel pins, as well as spent LWR fuel pins, is studied. The effects of self shielding and pulse width on the discrimination capability of the LSDTS are assessed. Two energy ranges (27.6 to 43.6 eV and 10.3 to 16.3 eV) are proposed for the assay of mixed-oxide fuel where discrimination between 235U and 239Pu is required. An error analysis of NDA with lead spectrometers that includes the calibration surfaces which occur in the assay of mixed-oxide fuel pins is given.
