RESUMO
Many commercially available software packages have been created to analyze gamma-ray spectra, but their source code has generally not been shared, although some users may wish to add or modify certain functionality, which is impossible without access to the source code. This study therefore presents a new open-source software package for the analysis of gamma-ray spectra. The name of the software is GSA (Gamma-ray Spectra Analysis), the source code of which is freely available through the GitHub website (https://github.com/LAHCEN-EL-AMRI/Gamma-Spectra-Analysis). The main function of this initial version of the software is to locate peaks, calculate areas, and identify corresponding radionuclides. A future version will complement this by measuring the concentrations of radionuclide elements. The software was validated by comparing its analysis results with those generated by three other software programs, namely Genie 2000, Maestro, and FitzPeaks. All the formulas used are explained in this work, which could be useful for researchers or students looking to create their own software packages for analyzing gamma-ray spectra.
RESUMO
The main objective of this study is to assess the behavior of the steel collimator plug (steel plug) dedicated to the Prompt Gamma Neutron Activation Analysis (PGAA) facility in the neutron beam tube (NB1) of the 2 MW Moroccan TRIGA Mark-II research reactor. The main function of this steel plug is to reduce the neutron and gamma beam cross section from 15 cm to 5 cm in diameter. This steel plug plays a crucial role in reactor safety because it replaces the original neutron beam plug while also stopping the entire incoming neutron beam. Three aspects were therefore involved in this study, including: i) the released heat induced by both neutron and gamma radiation, ii) the swelling effect caused by both radiation and temperature increases in the steel and iii) the radioactivity induced by neutron radiation in the steel plug. An MCNP6.2 model for the TRIGA Mark-II reactor was used to calculate the neutron spectrum inside the NB1 beam tube at the inlet part of the steel plug. A gamma spectrum of a 900 MW PWR reactor was used as input to account for the gamma radiation's effects on the steel plug. In order to select a convenient steel, two investigations were carried out for two grades of steel, namely mild steel (E235) and 304L stainless steel (SS304L). The results were calculated using an in-house FORTRAN-based program and validated using COMSOL, SPECTER codes, and "Neutron Activation and Scattering Calculator" tools. The results revealed that both the E235 and 304L steels are convenient from a safety point of view, although the E235 steel is preferred at the decommissioning stage.
RESUMO
The present study evaluates the distribution of metals over the last 100 years in the Oualidia lagoon by examining their concentrations in the sediment cores. The samples were analyzed by instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. Activities of 210Pb, 226Ra, and 137Cs were determined by gamma-ray spectrometry for establishing the age-depth relationships throughout the sediment cores by applying conventional models. The results indicated that the study area is contaminated by As and Cd revealing a detectable anthropogenic input of occurring metals as a consequence of the continuous development of human activities around the lagoon since 1950. The enrichment factor calculated for each layer of the three cores revealed that the studied sediments present no enrichment by Pb, K, and Mn; minor enrichment by Zn, Cr, Co, Cu, V, and Ni; and a moderately to severe enrichment by As and Cd. The pollution load index values increase from the bottom to the top of cores, and ranged from 0.9 to 2.8, which indicates levels of pollutants ranging from background to relatively high concentrations in the investigated sediments.
