[en] The sustainability of groundwater resources for drinking water supplies, agriculture, and industry is a prime concern in countries dominated by arid and semi-arid climates such as Morocco. The growing demand for groundwater coupled with impacts from land use and climate change make sustainability an even more important water management goal. In order to make sound decisions about water use and protection of water quality, water managers and policy makers must have a sound understanding of such factors as the location and amount of groundwater recharge and groundwater ages. Isotope methods have the added values of providing critical and rapid cost-effective ways to make sound decisions that standard hydrological or geochemical methods cannot provide. For many years, the National Water Authority and the National Centre for Nuclear Energy, Sciences and Technology (CNESTEN), with IAEA assistance, have worked together to characterize the groundwater of Morocco’s main aquifers using isotope and nuclear methods. The results of this endeavor have been published in a book entitled “Isotope hydrology Atlas of Morocco”. This Atlas demonstrates how isotope compilations can be used as a national and international resource for sustainable groundwater management, and should help promote increased utilization of isotope methods in other countries. The accumulated knowledge in isotope hydrology and the infrastructure established by CNESTEN and IAEA assistance are now made available to the countries of the region through the selected AFRA Regional Designated Centre and IAEA Collaborating Centre in terms of human capacity building and provision of advisory assistance and mentorship as well as analytical services. Accordingly, CNESTEN provided, over the last decade, analytical services, training, mentorship and advisory assistance to several countries from Africa, Asia and Europe. (author)

[en] This report highlights the results of chemical analyzes related to Major elements, traces and heavy metals carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 120 samples. The report presents the analytical techniques used (parameters and methods), a legend and the results tables.

[en] This report presents results related to Tritium analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal, within the framework of the RAF7011 project. It describes analytical method and instrumentation including general uncertainty estimation: Electrolytic enrichment and liquid scintillation counting; The results are expressed in Tritium Unit (TU); Low Limit Detection: 0.02 TU

[en] This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

[en] Highlights: • Heating-distribution calculation induced with neutron and Gamma beam. • Swilling effect induced with neutron and Gamma beam. • Induced radioactivity in the steel plug with neutron beam. 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.

[en] The Berrechid Basin located in the south of Casablanca is characterized by a semi-arid climate and it is intensely exploited for the supply of drinking and irrigation water. The geological features of this area have given the Berrechid aquifer a significant hydrogeological characteristic. To improve the understanding of the hydrogeological functioning of this basin, measurements of tritium concentrations in 71 groundwater samples and 8 surface water samples were used to study the groundwater age. The isotopic data of ¹⁸O showed two main components of the recharge of the Berrechid aquifer: the first one represents the non-evaporated waters resulting from the lateral flow from the Phosphate plateau mainly along the southern part of the basin and from the fast infiltration of rainwater in the North of the plain, and the second one results from the local recharge by vertical downward movement of evaporated water in the rest of the plain. Evaluation of the water transit times was calculated on the basis of the exponential and dispersion models of the Boxmodel program to the isotopic input and output data. Thus, the interpretation of tritium contents and residence times estimated using the lumped model (less than 20 years old) reveal that waters in the North and the South of the study area, are recent indicating a recent and continuous recharge, while the old waters coming from a local recharge in the rest of the basin reflects the occurrence of a low permeability lithology. (authors)

[en] A Turonian limestone-dolomite aquifer from the Tadla basin of Morocco was analysed using a multi-tracer approach (δ¹⁸O, δ²H, δ¹³C, ³H, ¹⁴C and noble gases) to reconstruct the paleotemperature evolution from the late Pleistocene to the Holocene. The Turonian aquifer was found to be suitable for a groundwater-based paleoclimate reconstruction, representing the Holocene–late Pleistocene epochs. After correction for young water contribution, mean residence times (MRTs) of groundwater were calculated using the Pearson radiocarbon model. Additionally, terrigenic helium content was used as an age indicator. Noble gas temperature (NGT) results from wells with groundwater ages corresponding to glacial periods showed an average of 17.2 ± 1.7°C. In contrast, samples of recent recharge water gave a mean NGT of 25.2 ± 1.3°C. This reveals a temperature difference of 8.0 ± 2.1 °C between the Holocene and late Pleistocene. This significant Pleistocene–Holocene temperature difference observed in Africa has considerable significance and can be extended to address an important topic relating to the nature of the wet epochs during which the fossil aquifers of North Africa were recharged. It is evident that this aquifer was recharged during both interglacial (warm) and glacial (cool) wet periods.