Federal Agency for Nuclear Control

Gas is produced in a deep geological repository mainly by metal corrosion of the waste and repository infrastructure. Since the Opalinus Clay (OPA) is a dense clay-rich host rock and the gas cannot be easily transported away, gas formation causes an increase in pressure that can affect the safety barriers. According to the current state of knowledge, there are four basic gas transport mechanisms in claystone: (i) gas movement by solution and/or diffusion; (ii) gas flow in the original porosity of the fabric, referred to as visco-capillary (or 2-phase) flow; (iii) gas flow along localised dilatant pathways; and (iv) gas flow along macro fractures similar in form to those observed in hydrofracture activities. The diffusion of gases through clay-rich rocks is relatively well understood and can be modelled to predict how the repository system will behave after closure. Considerable effort in recent years has been placed on understanding the advective transport of gas, which can occur if diffusion through the host rock is insufficient to keep the gas pressure low. The primary aim of the GT experiment was to gain definitive evidence of whether mechanism (ii) or (iii) are the dominant advective gas transport mechanisms in OPA.The GT experiment employed a complementary three-tier approach with (1) a series of closely constrained laboratory experiments helping to define (2) a field experiment at the Mont Terri underground research laboratory in Switzerland. (3) This were supplemented by modelling the experimental data. Both experimental programs were designed to observe the coupling of stress, strain, and pore pressure during gas movement.Four laboratory experiments were conducted: two with the long axis of the test sample parallel with bedding and two perpendicular. The samples dilated as gas started to move, with gas flow favouring pre-existing bedding planes.The field experiment was constructed at Mont Terri in November 2020 with a central injection borehole with three injection intervals surrounded by eight monitoring boreholes. All 8 monitoring boreholes had fibre optic cabling, with two boreholes having extensometers, one having extensometers/inclinometers, and one monitoring pore pressure. After a period of stabilisation and hydraulic testing, a gas injection test was initiated in September 2022. Coupling was seen between pore pressure, strain (extensometers & inclinometers; and fibre optics), and gas injection pressure at gas entry. Close examination of the response shows that gas movement was directional and not evenly distributed around the injection borehole.Confidence in experimental data is increased by modelling the data. This is being achieved through a PhD study and by modelling teams in the DECOVALEX-2027 HyMAR task. Similar experiments have been used previously in DECOVALEX and found to fail to represent all features seen in the data when using 2-phase flow codes. In HyMAR, the teams are modelling the experiments considering concepts such as damage to better represent the response seen in the data. Therefore, uncertainty in our understanding of the physics of gas migration in OPA has been tackled using a combination of laboratory, field, and modelling approaches.

Abstract In order to fulfil its mission, the Belgian Regulatory Body (constituted in Belgium by FANC and Bel V) has set up its own Research & Development programme, independent from the Waste Management Organisation's one. The Regulatory Body's Research & Development programme is mostly intended to investigate safety issues with the objective to be able to assess if the safety concept developed by the Waste Management Organisation fulfils the defined safety requirements. It includes the development and the follow-up of in situ experiments in underground research laboratories (e.g. in the Mont Terri project in Switzerland and at Tournemire in France). Such activities are essential to maintain and improve the scientific and technical skills, to strengthen the independence from the Waste Management Organisation and to build public confidence in the regulatory function. More generally, Research & Development in underground research laboratories is important to the Regulatory Body as it allows investigating processes, technologies and activities important to safety under in situ conditions. In particular, it is essential to accurately identify and characterize the processes upon which the safety functions of a disposal system rely, as well as processes that may affect the system performance. It is also necessary to demonstrate that construction and operational methods and technologies are technically feasible and can be implemented as assumed in the safety case. Such research and development activities are of great importance to properly manage some of the key uncertainties associated with a disposal programme and in particular to identify, characterize and reduce them where needed.

The international community has come a long way in developing a consensus that the remediation and management of naturally occurring radioactive materials and nuclear legacy sites will benefit from the use of the framework for risk-informed decision-making. Such a framework should ideally integrate risk assessment and decision-making. The framework presented in this paper specifically addresses the needs and expectations in the wider socio-economic and environmental context, as well as a narrower human health context. The framework was demonstrated as part of the International Atomic Energy Agency’s second Modelling and Data for Radiological Impact Assessments Programme. Three case studies, which have used or could use this integrative approach, are used for illustration. The first concerns remediation from uranium mining activities at Beaverlodge Lake in northern Saskatchewan, Canada, engaging stakeholders (also called ‘interested parties’) in the decision-making process on further options. The second case study suggests how decision analysis could support the selection of the best option for waste disposal for uranium ore processing at Žirovski vrh, Slovenia, taking into account a potential landslide and migration of waste throughout the adjacent valley in the event of flooding. The third case study presents the process and results of radiological safety assessment of the Kepkensberg sludge basin in Tessenderlo area, Belgium both before and after the disposal of material from remediation of the nearby Winterbeek River. It illustrates how such assessments could interface with decision analysis for the purpose of supporting the regulatory decisions related to future approval of a waste disposal option. Results show that formal stakeholder engagement in decision analysis provides a strong contribution to objective, robust, and transparent decision-making not only for radiation protection area but also in others where health and environmental impacts are of concern. A number of recommendations for future work have also been made.

A Educação numa perspectiva inclusiva é aquela onde todos os alunos dispõem das oportunidades para aprender de acordo com suas capacidades, sendo necessário o envolvimento de toda a comunidade escolar. A Educação Física (EF) se apresenta como indispensável nesse processo inclusivo, no qual suas aulas podem favorecer um ambiente lúdico para trabalhar as diferenças por meio dos seus conteúdos. Este estudo objetivou identificar o processo de inclusão de alunos com deficiência através das aulas de EF, baseado em uma revisão bibliográfica dos periódicos Scielo, CAPES e Google Acadêmico no qual foi estabelecido uma leitura exaustiva sobre a temática. Como resultado, constatou-se que mesmo depois de décadas, a inclusão de pessoas com deficiência ainda apresenta diversos desafios. Elaborar uma proposta de Educação Física Inclusiva não é algo simples, pois depende de vários fatores, tais como: a) Participação efetiva de toda a comunidade escolar, a relevância social e as estratégias didáticas e diversas possibilidades de acessibilidade e tecnologias educativas; b) Planejamento escolar amplo e comum a todos, buscando dar respostas educativas com respeito às diferenças, sempre reavaliando de acordo com as habilidades motoras e sociais de cada turma; e c) Participação conjunta dos alunos com e sem deficiência nas aulas e tarefas propostas e implementação de atividades complementares a partir de princípios pedagógicos da Educação Física Adaptada, buscando desenvolver habilidades que lhe permitam um maior sucesso.