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
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.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Mar 2025
Jul 2024
Latest Journal Issues
Nuclear Science and Engineering
March 2025
Nuclear Technology
Fusion Science and Technology
February 2025
Latest News
Grant awarded for advanced reactor workforce needs in southeast U.S.
North Carolina State University and the Electric Power Research Institute have been awarded a $500,000 grant by the NC Collaboratory for “An Assessment to Define Advanced Reactor Workforce Needs,” a project that aims to investigate job needs to help enable new nuclear development and deployment in North Carolina and surrounding areas.
Paul M. Keller, John C. Lee
Nuclear Science and Engineering | Volume 129 | Number 2 | June 1998 | Pages 124-148
Technical Paper | doi.org/10.13182/NSE98-A1968
Articles are hosted by Taylor and Francis Online.
A time-dependent collision probability method has been developed for the solution of neutron transport and nuclear reactor kinetics problems in one-dimensional slab geometry. The time-dependent collision probabilities permit the solution of time-dependent neutron transport problems involving general source distributions over an indefinite time period and an infinite number of collision generations. The method is based on the analytic integration of the time-dependent integral transport kernel involving purely real cross sections. The neutron time-of-flight and causality considerations lead to a number of complex formulas involving exponential and exponential integral functions. Occasional conflicts between the regular grid in time and space and the causality considerations lead to some formulas that are inexact. It is shown that these inexact formulas are terms of the third order in the time-step length, and thus the method has overall second-order accuracy in time. The method has been used to solve two types of neutron transport problems. The first, a pulsed, planar, fixed-source problem, yielded a flux solution with a root-mean-square relative difference of 0.94% from a benchmark analytic solution. The second problem solved was a pair of multigroup nuclear reactor kinetics problems. While the kinetics results were not conclusive, they suggest that diffusion theory may yield results that underestimate the amplitude and deposited energy of certain reactor transients.