This paper summarizes the experience gained in the application of multi-criteria decision making and uncertainty treatment methods to a comparative assessment of nuclear energy systems and related nuclear fuel cycles. These judgment measures provide a means for comprehensive evaluation according to different conflicting criteria, such as costs, benefits and risks, which are inevitably associated with the deployment of advanced technologies. Major findings and recommendations elaborated in international and national projects and studies are reviewed and discussed. A careful analysis is performed for multi-criteria comparative assessment of nuclear energy systems and nuclear fuel cycles on the basis of various evaluation and screening results. The purpose of this paper is to discuss the lessons learned, to share the identified solutions, and indicate promising future directions.

Germany is phasing-out the utilization of nuclear energy until 2022. Currently, nine light water reactors of originally nineteen are still connected to the grid. All power plants generate high-level nuclear waste like spent uranium or mixed uranium-plutonium dioxide fuel which has to be properly managed. Moreover, vitrified high-level waste containing minor actinides, fission products, and traces of plutonium reprocessing loses produced by reprocessing facilities has to be disposed of. In the paper, the assessments of German spent fuel legacy (heavy metal content) and the nuclide composition of this inventory have been done. The methodology used applies advanced nuclear fuel cycle simulation techniques in order to reproduce the operation of the German nuclear power plants from 1969 till 2022. NFCSim code developed by LANL was adopted for this purpose. It was estimated that ~10,300 tonnes of unreprocessed nuclear spent fuel will be generated until the shut-down of the ultimate German reactor. This inventory will contain ~131 tonnes of plutonium, ~21 tonnes of minor actinides, and 440 tonnes of fission products. Apart from this, ca.215 tonnes of vitrified HLW will be present. As fission products and transuranium elements remain radioactive from 104to 106years, the characteristics of spent fuel legacy over this period are estimated, and their impacts on decay storage and final repository are discussed.

The paper proposes a multicriteria decision analysis (MCDA) framework for a comparative evaluation of nuclear waste management strategies taking into account different local perspectives (expert and stakeholder opinions). Of note, a novel approach is taken using a multiple-criteria formulation that is methodologically adapted to tackle various conflicting criteria and a large number of expert/stakeholder groups involved in the decision-making process. The purpose is to develop a framework and to show its application to qualitative comparison and ranking of options in a hypothetical case of three waste management alternatives: interim storage at and/or away from the reactor site for the next 100 years, interim decay storage followed in midterm by disposal in a national repository, and disposal in a multinational repository. Additionally, major aspects of a decision-making aid are identified and discussed in separate paper sections dedicated to application context, decision supporting process, in particular problem structuring, objective hierarchy, performance evaluation modeling, sensitivity/robustness analyses, and interpretation of results (practical impact). The aim of the paper is to demonstrate the application of the MCDA framework developed to a generic hypothetical case and indicate how MCDA could support a decision on nuclear waste management policies in a "small" newcomer country embarking on nuclear technology in the future. Application ContextFrom a formal point of view, the decision problem formulation is a triplet consisting of (1) a set of potential alternatives which describe the possible actions that a decision-maker can undertake, (2) a set of points of view under which the potential actions are analyzed, evaluated, and compared, including different scenarios for the future, and (3) the problem statement. This section describes the problem application context.It should be noted that assessment of the technical performance and safety of repository sites is a very complex R&D problem. Therefore, the technical aspects of "repository" options will be only reviewed and briefly discussed within the confines of the paper. General criteria and metrics (indicators) which are in this case rather dynamic (time frame-dependent), are, however, addressed.In practice, the extent of R&D efforts is dependent on specific national conditions, for instance, available geological formations (rock medium) for final HLW disposal in a country and appropriate assessment of characteristics of nuclear waste that is necessary for designing a HLW repository. Thus the technology-holding countries have already established expert organizations responsible for final high-level waste disposal and conducting R&D activities on safety assessment studies, on minimization of the impact on the environment, and on site robustness tests (predictable performance response in the face of uncertainties).In order to construct an objective hierarchy tree, IAEA basic principles are therefore used. These principles for nuclear waste management st...

Abstract:In the present paper we have attempted to associate quantified impacts with a forecasted nuclear energy development in different world regions, under a range of hypotheses on the energy demand growth. It gives results in terms of availability of uranium resources, required deployment of fuel cycle facilities and reactor types. In particular, the need to achieve short doubling times with future fast reactors is investigated and quantified in specific world regions. It has been found that a crucial feature of any world scenario study is to provide not only trends for an idealized "homogeneous" description of the global world, but also trends for different regions in the world. These regions may be selected using rather simple criteria (mostly of a geographical type), in order to apply different hypotheses for energy demand growth, fuel cycle strategies and the implementation of various reactor types for the different regions. This approach was an attempt to avoid focusing on selected countries, in particular on those where no new significant energy demand growth is expected, but instead to provide trends and conclusions that account for the features of countries that will be major players in the world energy development in the future.

Abstract:Is it true that a nuclear technology approach to generate electric energy offers a clean, safe, reliable and affordable, i.e., sustainable option? In principle yes, however a technology impact on the environment strongly depends on the actual implementation bearing residual risks due to technical failures, human factors, or natural catastrophes. A full response is thus difficult and can be given first when the wicked multi-disciplinary issues get well formulated and "resolved". These problems are lying at the interface between: the necessary R&D effort, the industrial deployment and the technology impact in view of the environmental sustainability including the management of produced hazardous waste. As such, this problem is clearly of multi-dimensional nature. This enormous complexity indicates that just a description of the problem might cause a dilemma. The paper proposes a novel holistic approach applying Multi-Criteria Decision Analysis to assess the potential of nuclear energy systems with respect to a sustainable performance. It shows how to establish a multi-level criteria structure tree and examines the trading-off techniques for scoring and ranking of options. The presented framework allows multi-criteria and multi-group treatment. The methodology can be applied to support any pre-decisional process launched in a country to find the best nuclear and/or non-nuclear option according to national preferences and priorities. The approach addresses major aspects of the environmental footprint of nuclear energy systems. As a case study, advanced nuclear fuel cycles are analyzed, which were previously investigated by the Nuclear Energy Agency (NEA/OECD) expert group WASTEMAN. Sustainability facets of waste management, resource utilization and economics are in focus.Keywords: advanced nuclear fuel cycles; waste management; resource utilisation; economics; performance comparison, multi-criteria decision analysis; sensitivity/uncertainty analysis, environmental footprint BackgroundInnovative electrical energy generating technologies should be sustainable, i.e., clean, safe, reliable and affordable and moreover able to preserve resources and minimise liabilities [1]. The nuclear technology option might compete in this sense with other large-scale energy producing technologies as, for instance those consuming coal or oil resources [2]. However, very much like other non-nuclear energy generation options, a nuclear option produces hazardous radioactive waste (radwaste)-called high-level waste (HLW) that contains long-living radionuclides. Therefore HLW should be isolated from the biosphere by a disposal site/system and an enclosure in special facilities, called HLW repositories [3]. This is the reason why nuclear waste management is of public concern in some