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Hanford begins removing waste from 24th single-shell tank
The Department of Energy’s Office of Environmental Management said crews at the Hanford Site near Richland, Wash., have started retrieving radioactive waste from Tank A-106, a 1-million-gallon underground storage tank built in the 1950s.
Tank A-106 will be the 24th single-shell tank that crews have cleaned out at Hanford, which is home to 177 underground waste storage tanks: 149 single-shell tanks and 28 double-shell tanks. Ranging from 55,000 gallons to more than 1 million gallons in capacity, the tanks hold around 56 million gallons of chemical and radioactive waste resulting from plutonium production at the site.
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.