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.
Explore membership for yourself or for your organization.
Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
September 2025
Nuclear Technology
Fusion Science and Technology
August 2025
Latest News
Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
J. A. Favorite, W. M. Stacey, Jr.
Nuclear Science and Engineering | Volume 125 | Number 1 | January 1997 | Pages 101-106
Technical Note | doi.org/10.13182/NSE97-A24258
Articles are hosted by Taylor and Francis Online.
A new variational functional for space-time neutronics is presented. This functional is stationary about the integro-differential form of the diffusion equation, in which the delayed neutron source is expressed as a convolution integral of the flux, and an integro-differential adjoint flux equation. The new functional is used to derive a quasi-static method that is similar to the improved quasistatic (IQS) method, except that the equation for the flux shape uses a different expression for the delayed neutron source. In a one-dimensional sub-prompt critical test problem, the new variational quasi-static method was slightly more accurate than the IQS method.