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 126 | Number 3 | July 1997 | Pages 282-292
Technical Paper | doi.org/10.13182/NSE97-A24481
Articles are hosted by Taylor and Francis Online.
A new variational estimate for dynamic reactivity that accounts for delayed neutron holdback is introduced and adapted for use with the improved quasistatic (IQS) method. Numerical tests on a large light water reactor model indicate that the computational effort required with the IQS method can be reduced by a factor of 3 to 4 by using this new variational estimate of dynamic reactivity. With comparable computational effort, the accuracy of the standard IQS method, which uses the flux shape interpolation/recomputation procedure and a first-order estimate of static reactivity, can be improved by using a standard variational estimate without the flux shape interpolation/recomputation procedure, and it can be further improved by using the new variational estimate of dynamic reactivity.
