Projeto PRR

Sumário

The assistant researcher will integrate two research groups of C2TN (Radiation Protection Safety and Nuclear Engineering and Techniques groups) aligned with the two scientific areas of DECN (Chemical and Radiopharmaceutical Sciences and Nuclear Technologies and Radiological Protection).Radioactive waste management policies and practices in Portugal also must comply with the Council Directive 2011/70/Euratom, now transposed to the national law as Decree-Law 156/2013, with the obligation to setup the national plan for the management of radioactive wastes already in place (from the regulator APA). Among other obligations, there are the IAEA Joint Convention on safety of management of spent fuel and safety of management of radioactive waste. Although Portugal has an interim storage facility, until a decision regarding the final disposal facility is made in the national plan for radioactive waste management (RWM), the problem of RWM has become urgent because, similarly to other countries, Portugal records an increasing production of radioactive waste from medical, industrial and research applications of radioactive materials in the form of sealed and unsealed sources.Many countries, such as France and Sweden, have developed research in the study of radioactive waste disposal, focusing on the characterization of their national resources for the task of sealing High-Level Waste (HLW) on underground facilities or other disposal site configurations. Unlike these countries, Portugal as a SIMS country (small inventory member states) does not have nuclear reactors, therefore there is no national HLW, but Low Level Waste (LLW) and Intermediate Level Waste (ILW), therefore the approach has to be slightly different from theirs.The contribution for the development of this line of research could contribute to the field of knowledge of eligible materials, establishing suitability models depending on the chemical, physico-chemical and textural characteristics of geomaterials.The key tasks assigned to the researcher encompass:Typical characterization methodology for clay minerals and cementitious materials (X-Ray Diffraction, chemical analyses and electron microscopyPhysical-chemical properties, i.e. the specific surface and the Cation Exchange Capacity (CEC)Characterization of geomaterials with potential for Cs adsorption towards their use as sealing materials and engineering barrier systems at waste repositories. Samples will be irradiated to observe how the exposure to radiation affects propertiesKinetical modelling of the sorption of radionuclides into the studied materialsThe importance of these characterization is determined by their intricate linkage. The texture of the samples (observed through Scanning Electron Microscopy), conditions the specific surface of the samples and the CEC. These parameters will have an impact on the adsorption/desorption potential of radionuclides. There is a series of studies focusing on the migration of radionuclides in sites subject to host radioactive waste repositories both for HLW and L-ILW and in natural materials because of the environmental problems enhancing the importance of these studies.Radionuclide sorption experiments will be performed according to the conventional protocols used worldwide: batch reactors under static conditions, conventional column experiments and, finally, open systems (dynamic) using flow-through reactors. A kinetical modelling of the sorption of radionuclides into the materials studied will be performed. It is expected that these models can be applied (or easily adapted) to different liners in near-surface radioactive repositories.The scientific profile should align with the designated tasks, requiring a highly motivated candidate in the field of environmental geochemistry and radioactivity ,  and experimental tasks. The candidate should possess a comprehensive skill set encompassing theoretical knowledge, practical experimentation capabilities, and a proven history of interdisciplinary research on environmental geochemistry and radioactivity.The decision to hire an employee in this field is driven by crucial considerations that hold significance for both C2TN and DECN. It aligns with the prioritized research areas of environment quality, health impact assessment and affordable and clean energy as recognized by esteemed international bodies such as the European Union, World Health Organization, and United Nations. Furthermore, this strategic hiring is integral to ensuring that IST maintains its position at the forefront of scientific exploration in the  Environmental Geochemistry & Radioactivity and  Radioactive waste management  field.Beyond its impact on research excellence, the employment of an expert in this field will also enhance the quality of education provided to DECN students, as well as will consolidate a relevant strategic area at DECN and IST, comprising one of the missions of IST within the DL 29/2012.