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
2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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
Dec 2025
Jul 2025
Latest Journal Issues
Nuclear Science and Engineering
December 2025
Nuclear Technology
Fusion Science and Technology
November 2025
Latest News
Modernizing I&C for operations and maintenance, one phase at a time
The two reactors at Dominion Energy’s Surry plant are among the oldest in the U.S. nuclear fleet. Yet when the plant celebrated its 50th anniversary in 2023, staff could raise a toast to the future. Surry was one of the first plants to file a subsequent license renewal (SLR) application, and in May 2021, it became official: the plant was licensed to operate for a full 80 years, extending its reactors’ lifespans into 2052 and 2053.
Deokjung Lee
Nuclear Science and Engineering | Volume 174 | Number 3 | July 2013 | Pages 300-317
Technical Paper | doi.org/10.13182/NSE12-27
Articles are hosted by Taylor and Francis Online.
The impact of the dynamic condensation of energy groups on the convergence characteristics of the coarse mesh finite difference (CMFD) algorithm has been analyzed within the framework of two-group (2-G) one-node (1-N) local kernel (CMFD1N) and one-group or 2-G global CMFD formulations. Three algorithms were analyzed by the method of linearizing the nonlinear algorithms and applying Fourier analysis to the linearized algorithms: partial current sweep (PCS), CMFD1N, and CMFD1N with dynamic condensation (CMFD1N-DC). Because of the dynamic condensation, the spectral radius of the CMFD1N-DC algorithm is influenced by the other two algorithms; i.e., it shows a similar behavior to the PCS algorithm for small mesh sizes and a similar behavior to the CMFD1N algorithm for large mesh sizes. From the theoretical derivation, it was shown that the spectral radius is determined by the combination of partial current spectrum update in the local PCS kernel and the current correction factor update in the global CMFD. Specifically, the convergence properties of the CMFD1N-DC algorithm follow those of the PCS algorithm for small mesh sizes since the energy spectrum is only updated in the local kernel. It was also observed that the relaxation parameter for the CMFD1N-DC algorithm needs to be determined with the fast group cross-section data because of the dynamic condensation.
