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 ANS Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
Latest Magazine Issues
Mar 2026
Jan 2026
Latest Journal Issues
Nuclear Science and Engineering
March 2026
Nuclear Technology
February 2026
Fusion Science and Technology
April 2026
Latest News
MARVEL PDSA approval could serve as blueprint
MARVEL, the Microreactor Applications Research Validation and Evaluation project at Idaho National Laboratory, has had its preliminary documented safety analysis approved by the Department of Energy, marking a milestone in its development and serving as a potential outline for other microreactors in development.
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.