Predisposal Management of Radioactive Waste: Digital Decision Support System - 23237

The PREDIS, 'Predisposal management of radioactive waste' project builds upon earlier work on international roadmaps and strategic research agendas yet strives to make significant advances to foster wider holistic perspectives to the pre-disposal needs and priorities for the future. The project structure was established to address four waste streams identified as priority areas by the end user community and identified in the scope of the European Joint Programme (EJP) in Radioactive Waste Management: metallic wastes, organic wastes in the form of liquids or solids, and cemented waste packages. This abstract gives an overview of the progress and future work with a focus on the management of cemented waste. The state-of-the-art report (SOTA) [2] on the monitoring of cemented waste (during preparation, handling and long-term storage) has been published and is based on information collected and compiled with a questionnaire that was answered by PREDIS end users (SOTA-2021-04-14 (predis-h2020.eu)). A series of webinars aimed at identifying the gaps, challenges and opportunities was organized. The best suited forms of the mock-ups, to select the test specimens that will be used to evaluate the monitoring methods, were identified, and serve as the basis on which the digital simulations (Digital Twin Technology) are developed in the project. A list of non-destructive test methods has been set up to identify monitoring and condition assessment technologies, useful to identify problematic waste packages at an early stage. A subset of these technologies, mostly affordable wireless techniques to be installed on or even inside packages, will be improved and evaluated in the frame of PREDIS Work Package 7 'Innovations in cemented waste handling and pre-disposal storage'. Since the degradation phenomena play a key role, several laboratory-scale alkali-silica reaction (ASR) experiments have been successfully implemented with the aim of testing instrumentation technology during ASR progress. The development of a toolkit 'Digital twin' was started by building a working prototype of the Digital Twin. This prototype is designed to accommodate changes as its development will be an iterative process using input from end-users as well as from partners who provide detailed model data. A PREDIS case study has been set-up by considering the expected input data to classify all information to be associated with the waste. The Microsoft Azure platform has been chosen between the partners involved as an initial data platform on top of which the data handling and processing will be carried out. A significant amount of cemented waste is classified as intermediate level waste implying that long-term storage will be required before geologic disposal is available. Currently, the cemented waste-form package degradation is primarily confirmed by visual inspection, i.e., after package failure. To increase safety, reduce uncertainty and make possible decision making for intervention a framework for supporting decisions on maintenance of cemented waste packages in waste management facilities is under development. The processes at a radioactive waste storage are procedures-in-series where tasks and options must be selected, and this selection will be more efficient when supported in the decision framework. The modelling and data analyses techniques supporting this decision framework will include (i) data learning for creating and maintaining a DTw of a radwaste store(s), (ii) modelling and data analyses packages for individual waste packages integrated with digital models of the waste packages, (iii) process modelling for planned or possible maintenance activities, both manual and semi-/automated options, in normal and accidental conditions. In addition, physics models (mainly radiation transport) for assessing human exposure to radiation during required maintenance activities will be taken into account. A prototype of digital decision support system based on the decision framework will be designed. Method development for using the above digital decision framework for optimization of package design, package arrays, and automation with respect to specific waste store requirements will be evaluated and partially tested. This task is foreseen to include designing and prototyping of a waste route modelling system utilizing the outcomes on LCA and life cycle cost (LCC) from tasks that connect initial waste forms to possible final waste packages that conform to store specific WAC through a modelling of all possible intermediate waste treatment and temporary storage steps and their foreseen associated contribution to life cycle cost and environmental impact. (authors)