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.
Simone Santandrea
Nuclear Science and Engineering | Volume 155 | Number 2 | February 2007 | Pages 223-235
Technical Paper | Mathematics and Computation, Supercomputing, Reactor Physics and Nuclear and Biological Applications | doi.org/10.13182/NSE155-223
Articles are hosted by Taylor and Francis Online.
This paper presents recent developments of the acceleration techniques for the method of characteristics (MOC) in the code APOLLO-2. The main contribution concerns the introduction of a multidomain DPN technique where all regions belonging to the same macrodomain are coupled by an integral operator that is strictly equivalent to the MOC. Different macrodomains are coupled via currents that are defined with the DPN formalism. This new integral DPN(IDPN) operator is built by using transmission and escape probability factors that respect symmetries/antisymmetries and complementary properties that are enforced to preserve the physics of the problem and to save computational effort. These factors are computed using the numerical tracking of the MOC operator. This paper presents results on realistic assembly calculations that demonstrate the effectiveness of the IDPN operator as a synthetic acceleration tool.
