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[en] In this paper, a review of radioactive wastes treatment using thermal plasma technology is presented as a treatment method for radioactive waste management. Virtually all waste streams can be treated by the thermal plasma technologies, resulting in a conditioned product, free from organics and liquids, definitely meeting the acceptance criteria for safe storage and disposal. The application of the thermal plasma system in the nuclear area is still one of the current research topics due to the theoretical and practical complexity of the treatment. This paper discusses the performance of the thermal plasma systems, addressing the advantages and limitations of the method. (author)
[en] At the research presentation meeting of the Radioactive Waste Management Funding Center (RWMC) held in December 2019, the results of the survey and research, which were summarized from the perspective of the title were introduced. This paper, as Part 2 of the series, deals with the role of engineering technology toward the performance evaluation (the above subtitle). As part of the project commissioned by the Agency for Natural Resources and Energy, RWMC is working to develop a quality assurance system and monitoring technology relating to manufacturing and construction technology in the geological disposal business. RWMC aims to realize the engineering approach of constructing a quality assurance system for geological disposal facilities that require long-term safety after closure. This paper organized the theory by positioning the challenges such as mutually related quality assurance, monitoring, and performance confirmation as the challenges to contribute to the judgment of the final closure of facilities (an effort to contributes to more reliable performance evaluation in the development of safety cases), and discussed the direction of future research and development. (A.O.)
[en] Reliable methods for estimating the cost of a radioactive waste disposal programme are crucial to ensure that the necessary funding for completing the disposal programme is available. Estimating the cost for disposal is however a challenging and complex task. Disposal programmes themselves are complex and long-term undertakings and conditions can be expected to change significantly over the time-span during which a disposal programme is developed and implemented. This publication provides Member States with guidance on how to develop cost estimates for a disposal programme and on how to establish funding mechanisms. It will help readers in becoming informed clients by familiarizing themselves with the approaches and complexities in cost estimates and funding mechanisms for disposal. The publication is applicable to all waste categories and both near surface and geological disposal. It contains relevant examples and case studies from national programmes. The cost figures are intended to give an indication of the possible cost of certain parts or aspects of the disposal programme rather than to compare different disposal programmes’ costs.
[en] Comparing the costs of different power generation technologies has become one of the main arguments used by proponents of specific sources and those seeking to find the best approach to plan the expansion of electrical systems. However, this approach, taken alone for public energy policy making, is far from simple and can lead to unwanted and unexpected results. How much does it cost? It seems like a simple question. However, when it comes to competing power generation technologies, it is an extremely challenging question. Generation costs include many variables: capital, fuel, location, waste disposal, environmental impact, interconnection, reliability, intermittency, and other external and systemic costs. No two technologies are alike. System costs are often divided into the following four broadly defined categories of profile costs (also referred to as utilization costs or backup costs), balancing costs, grid costs and connection costs: – Profile costs refer to the increase in the generation cost of the overall electricity system in response to the variability of VRE output. – Balancing costs refer to the increasing requirements for ensuring the system stability due to the uncertainty in the power generation (unforeseen plant outages or forecasting errors of generation). – Grid costs reflect the increase in the costs for transmission and distribution due to the distributed nature and locational constraint of VRE generation plants. – Connection costs consist of the costs of connecting a power plant to the nearest connecting point of the transmission grid.
[en] Science and engineering provide the necessary answer to the ultimate question in radioactive waste management and disposal: How safe is the management approach and the repository system? The credibility of that answer is founded on underlying processes and systems that demonstrate the reliability of the information used to answer this singularly important question. This technobureaucratic culture is often assumed to be effortless and is taken for granted, and assumptions like this can lead to unacceptable results. These non-technical processes fall into two broad but related categories; regulatory compliance and information/knowledge management. In addition to specific technical regulatory requirements, in the United States (U.S.), the U.S. Nuclear Regulatory Commission (NRC) requires compliance with several abstract concepts that it views as essential to demonstrating that an organization has the requisite wherewithal to be a licensee, such as Nuclear Safety Culture, Safety Conscious Work Environment, and Quality Assurance. These concepts greatly influence all the technobureaucratic processes and systems that support the science and engineering work. This paper presents a generic framework for an organization and the functions of the organizational elements necessary to execute a generic radioactive waste repository development effort. These organizational elements reflect a workforce‘s functional composition and the practices that facilitate meeting all of the NRC‘s expectations. Successful implementation of a plan to develop a repository requires an effective organization and infrastructure designed to execute the effort in compliance with regulatory expectations. The discussions in this paper are based on the current U.S. statutory and regulatory framework. Notably, the context in which the organization‘s work will be conducted differs substantially from that of the typical research, development, and demonstration (RD&D) environment. First, there are work elements that are not customarily included in RD&D work, such as regulatory compliance, a corrective action program, technical configuration controls, and requirements/commitment management. Secondly, the rigor with which organizational assurance and quality assurance functions need to be applied and practiced is greater than necessary in the typical RD&D environment. One all-too-frequently overlooked component of a compliance-oriented endeavor is the importance of having an outcome-aware management and business organization, technical support, and information management technologies. Successfully accomplishing such an endeavor requires more than world-class science and engineering. It is equally important that the technical team be supported by an experienced and proficient non-technical infrastructure. (author)
[en] Various issues of deep geological disposal of radioactive waste, including alternatives to geological disposal, multinational approaches and costing / financing aspects are being discussed in the public and political sphere in a recurrent manner. EDRAM believes, as a group of senior executives from national agencies for implementing radioactive waste disposal in their respective countries, that drawing on international expertise, experience and collaboration is of great value and leads to better solutions for the safe implementation of radioactive waste disposal. Based on this belief EDRAM discusses strategic issues and technical and management matters, with a view to benchmarking and establishing best practices, develops a common understanding of waste management issues among implementers and positions thereof and coordinates actions in relation to international organisations. EDRAM continually exchanges information on these matters within the group and with international organizations and understands differences and commonalities among them deeply in order to be able to explain them to its stakeholders. In the paper summarized are some of major recent outputs from this discussion. (author)
[en] A recognized waste disposal concept and its troubles. For about 40 years, deep geological disposal of radioactive and chemical waste has become the most widely recognized strategy for eliminating waste. However, this pole position in the ranking of concepts contrasts with the daily lived situation in the field, as exposed here.
[en] Radioactive waste disposal site “Pidlisnyi” was commissioned in December, 1986. It is a surface storage facility with modular type design. Modules are formed by walls built from concrete blocks placed on common background of 1.5 m thick concrete slab. The storage facility was intended for disposal of radioactive waste with exposure rate from 5 R/h to 250 R/h. The A1 module survey of 2018 included studies of surface dose rates and also gamma ray well logging. During the survey, 16 wells were drilled down to the radioactive waste layer. Analysis of the drilling results revealed that thickness of radioactive waste layer varies from 0.7 to 2 m across the A1 module. Activity distribution in the radioactive waste layer is essentially nonuniform. According to the well logging data dose rate inside the well is within 7.5 to 130 mSv/h range. For the calculations, we developed spatial model of the storage facility based on the survey data. The model describes profiles of radioactive waste layer, concrete layer and gravel-sand covering. To build the model we divided module area into 16 rectangular fragments. For each fragment thicknesses of the corresponding layers were constant and defined by the drilling results. To assess the fuel amount and total radioactive waste activity for the A1 module of “Pidlisnyi” disposal site we used Monte Carlo simulation with MCNP5 trans - port code. The calculated value of the total activity of about 1.1 ∙ 10 15 Bq is close to the value obtained in the previous paper using simplified model and MicroShield code. We also performed assessment of the fuel amount inside the module using various approaches and found it to be below 0.8 % from total fuel amount in the Chornobyl NPP unit 4 before the accident. (author)
[en] This study investigated the physical-mechanical effects of cement-lime mortars containing recycled aggregate of construction and demolition waste (CDW). The natural aggregate (NA) was replaced by volume at 25%, 50%, 75% and 100% by mixed recycled aggregate (MRA) obtained from the CDW crushing. Five types of mortars were prepared with a volumetric ratio of 1:1:6 (cement, lime and aggregate) and water/binder ratio based on the fixed consistency of 260 mm. The effects of MRA on fresh and hardened mortars’ properties were analyzed. The results were analyzed using a one-way ANOVA. MRA incorporation improved most of the physical-mechanical properties of mortars tested, except for hardened bulk density, water absorption and porosity. In the long-run, mechanical strengths significantly increased in all compositions, especially those with higher percentages of MRA. The results obtained showed that the use of MRA in masonry mortars is an alternative to reduce the generation of waste and consumption of natural resources.
[es]Este estudio investigó los efectos físico-mecánicos de los morteros de cemento y cal con áridos reciclados de residuos de construcción y demolición (RCD). El árido natural (AN) se reemplazó en volumen al 25%, 50%, 75% y 100% por el árido reciclado mixto (ARM) obtenido de la trituración de RCD. Se prepararon cinco tipos de morteros con una relación volumétrica de 1: 1: 6 (cemento, cal y áridos) y una relación de agua / aglomerante en función de la consistencia fija de 260 mm. Se analizaron los efectos del ARM en las propiedades de los morteros frescos y endurecidos. Los resultados se analizaron utilizando un ANOVA-simple. La incorporación de ARM mejoró la mayoría de las propiedades físico-mecánicas de los morteros, excepto la densidad aparente endurecida, la absorción de agua y la porosidad. A largo plazo, las resistencias mecánicas aumentaron significativamente en todas las composiciones, especialmente en aquellas con porcentajes más altos de ARM. Los resultados obtenidos mostraron que el uso de ARM en morteros de albañilería es una alternativa para reducir la generación de residuos y el consumo de recursos naturales.
[en] One of the major concerns with the continued growth of the nuclear power industry is the production of the high level radioactive wastes which are by-products of the fission process. The risks associated with the disposal of high level wastes derive from the potential for release of radioactive materials into the environment. The assessment of these risks requires a methodology for risk analysis, an identification of the radioactive sources, and a method by which to express the relative hazard of the various radio nuclides that comprise the high level waste. Radioactive wastes are either contained or discharged. Contained wastes are either stored or disposed of in trenches, caverns, or deep mines. On the other hand, some gaseous and liquid wastes are discharged from chimney stacks or sea pipelines directly into the environment. Contained wastes either decay before escaping from their disposal site or are arranged to leak at such a low rate as not to raise appreciably the level of radiation in the environment. In the multiple barrier approach, each containment is a reliable barrier to migration-the packaging material (glass or concrete), the vault and backfill, and the geology. (author)