Belsim (Belgium)

Optimization can be defined as the process of making a system as good or effective as possible. In the context of radioactive waste management (RWM), continuous improvement and optimization are inherent ambitions of every disposal program. However, the terminology and understanding of optimization vary across programs, countries, and stakeholders. Relevant RWM stakeholders include implementers (waste management organizations), regulators, technical support organizations, research entities, and civil society organizations. These stakeholders exhibit distinct views of optimization, attributable notably to their heterogeneous roles and needs in a RWM program. The EURAD-2 work package OPTI provides a platform for interactions between members from the three EURAD colleges as well as CSOs, on the optimisation of HLW GDFs. These views about optimisation were discussed in a workshop held January 2025. A paper summarizing the conclusions of this workshop was prepared and discussed further. The intention of the contribution is to present the content of the paper and open the discussion to a larger group.The exchange was centred around the “WHY?”, the “HOW?” and the “WHEN?” there are needs and priorities for optimisation. For instance, views on the possible scope for optimisation at the different phases of a RW disposal programme, the main challenges for optimisation and the best or existing approaches to optimisation were collected during the workshop. Some key observations on optimization emerge. Optimization is relevant for all stages of a repository program and optimisation must be considered holistically. It means that the disposal system has to be optimised as a whole, considering several optimisation processes that take place in parallel, such as the optimisation of the protection (radiological and non-radiological) and the optimisation of the resources required (and therefore the costs). The process of optimisation must be carried out taking account of prevailing circumstances, including the regulatory framework, the status of knowledge and the available resources (e.g. financial). However, the priorities shift over the lifetime of the program. At the start of a disposal programme, the focus of the disposal system optimisation is mainly on optimising the protection. Optimization in earlier stages, e.g. preparation of the safety case and licensing, is an established engineering process ensuring compliance with regulatory requirements and enhancing the overall safety of repository systems. Then, once the safety strategy and safety concept have been optimised and agreed with the regulator, the programme enters its next phases and the focus shifts progressively towards optimising the resources needed to implement the safety strategy and safety concept. At later stages, optimization after licensing or during construction and operation may have a different focus, as safety is already demonstrated (e.g. focus on reduction of conservative assumptions, optimization of the procurement of materials). Thus, various approaches and limits to optimization can be defined at different program stages; the prevailing circumstances of each national program set a frame in which optimization can be done. Furthermore, economical drivers, developments in science and technology, and interactions with the society can outmanoeuvre the optimization process.

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.

Decisions associated with Radioactive Waste (RW) Management programmes are made in the presence of irreducible and reducible uncertainties. Responsibilities and roles of each actor, the nature of the RW disposal programme and the stage in its implementation influence the preferences of each category of actors in approaching uncertainty management. UMAN (UMAN – Uncertainties Management Multi-Actor Network is a Work Package of the European Radioactive Waste Management Programme – EURAD) carries out a strategic study about the management of uncertainties based on extended exchanges among actors representing Waste Management Organisations, Technical Support Organisations, Research Entities and Civil Society, a review of knowledge generated by past and ongoing R&D projects, and findings of international organisations. UMAN discusses the classification schemes and approaches applied in uncertainty management, and identifies possible actions to be considered in the uncertainty treatment. The relevance for the safety of the uncertainties associated with waste inventory, including spent fuel, near-field, site and geosphere and human aspects, as perceived by each type of actors, and approaches used in their management are explored with the aim to reach either a common understanding on how uncertainties relate to risk and safety and how to deal with them along the programme implementation, or at least arrive at a mutual understanding of each individual view. Finally, uncertainties assessed as highly significant and the associated R&D issues that can be further investigated are being identified.

Abstract The validation of multiphase flowmeters (MPFMs) in a controlled flowloop using live hydrocarbon fluid is examined with emphasis on the impact of measured and modelled fluid properties uncertainty on the loop reference measurements. A customized process model based on data reconciliation with integrated thermodynamics package is built to evaluate the loop reference flowrates and their uncertainties at the multiphase flowmeter test station conditions. The process model accounts for data redundancy and physical constraints to ensure consistency of the reconciled measured and unmeasured variables used in the validation of multiphase flowmeters. The model is applied to a generic set of test points performed in a high pressure (HP) flowloop. The paper discusses the modeling and operational aspects involved in validating the subsea meter's measured flowrates. It also highlights the sensitivity of different inputs and their uncertainties on MPFM performance evaluation. For the first time, the proposed approach enables operators to achieve the reality of subsea operations inside a highly controlled flowloop environment without resorting to overly simplified assumptions and practices. The approach is further validated by applying it to a high-pressure, high-volume, true multiphase flowloop using actual hydrocarbon fluids.

The study of the microbiotas of 19 Italian sourdoughs used for the manufacture of traditional/typical breads allowed the identification, through a culture-dependent approach, of 20 and 4 species of lactic acid bacteria (LAB) and yeasts, respectively. Numerically, the most frequent LAB isolates were Lactobacillus sanfranciscensis (ca. 28% of the total LAB isolates), Lactobacillus plantarum (ca. 16%), and Lactobacillus paralimentarius (ca. 14%). Saccharomyces cerevisiae was identified in 16 sourdoughs. Candida humilis, Kazachstania barnettii, and Kazachstania exigua were also identified. As shown by principal component analysis (PCA), a correlation was found between the ingredients, especially the type of flour, the microbial community, and the biochemical features of sourdoughs. Triticum durum flours were characterized by the high level of maltose, glucose, fructose, and free amino acids (FAA) correlated with the sole or main presence of obligately heterofermentative LAB, the lowest number of facultatively heterofermentative strains, and the low cell density of yeasts in the mature sourdoughs. This study highlighted, through a comprehensive and comparative approach, the dominant microbiotas of 19 Italian sourdoughs, which determined some of the peculiarities of the resulting traditional/typical Italian breads.

Sovyetler Birliği deneyimi 20. yüzyıla damgasını vurmuştur. Bu nedenle Sovyet dış politikası, bu politikanın belirlenme süreci ve uygulayıcıları ayrı ayrı incelenmeye değerdir. Andrey Andreyeviç Gromıko SSCB’nin 28 yıl kesintisiz dışişleri bakanlığını yapan meslekten diplomat biridir. Diplomatik kariyeri 1939’da başlayıp 1985’te sona ermiş, yarım yüzyıla yaklaşan bir sürece yayılmıştır. Bu çalışmanın temel sorunsalı Sovyet diplomasisine damgasını vurmuş bir diplomat olan Gromıko’dur. Gromıko’nun yaşam öyküsü birbirinden ilginç ve zengin deneyimlerle taçlanmışsa da kendi başına bir bilimsel çalışma konusu olamaz. Bu nedenle, çalışmada Sovyet dış politikası üç döneme ayrılmıştır. Her dönemde Sovyet dış politikasının temel eğilimleri saptanmış ve Gromıko’nun oynadığı rol sorgulanmıştır. Gromıko yalnızca Sovyet diplomasisine değil, uluslararası sisteme damgasını vurmuş yüzyılın en önemli diplomatlarından biridir.