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.
R. G. Gonzalez, F. D'Auria, O. Mazzantini
Nuclear Technology | Volume 194 | Number 1 | April 2016 | Pages 61-72
Technical Paper | doi.org/10.13182/NT14-155
Articles are hosted by Taylor and Francis Online.
Atucha-2 is a Siemens-designed pressurized heavy water reactor located in Argentina. Its geometrical complexity and peculiarity [e.g., oblique control rods (CRs) and positive void coefficient] required a developed and validated complex three-dimensional (3-D) neutron kinetics (NK) model. In the framework of the agreement between NA-SA (Nucleo-electrica Argentina Sociedad Anonima) and the University of Pisa, a detailed NESTLE (3-D NK code) model of the Atucha-2 nuclear power plant (NPP) was developed. This document summarizes the procedures for implementing oblique CRs into the RELAP5/NESTLE model: A particular arrangement of the RELAP5/NESTLE CR insertion mode for oblique CRs and an implementation into the homogenized two-group cross sections of ad hoc calculated correction factors (these parameters were obtained by previously executed Monte Carlo calculations) were developed. Some applications, among the scenarios selected to perform safety analysis (Final Safety Analysis Report) of the Atucha-2 NPP (CNA-II), are also reported: preliminary scram rod worth, analysis of a CR ejection accident, and a CR faulty withdrawal.