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[en] The investigation of the thorium fuel cycle (ThFC) is a collaborative INPRO (International Project on Innovative Nuclear Reactors and Fuel Cycles) activity within its main area on global vision on sustainable nuclear energy for the 21st century. The current publication reports on the sustainability of nuclear power by re-examining the potential of thorium-based fuel cycles to support future large scale deployment of nuclear energy systems by increasing the availability of nuclear material. Special attention is paid to the thorium fuel cycle from the point of view of economics and proliferation resistance.
[en] Mindful of possible future limitations on the availability of uranium, the introduction of the thorium fuel cycle is potentially a complementary source of nuclear energy. This publication assimilates current knowledge of thorium geology and mineralization into a brief account on the worldwide occurrence of thorium resources. Although thorium is currently not commercially viable as a fuel, it is important to pre-emptively assess thorium related information should that situation change. Thus, the publication provides an overview of the variety of natural thorium deposit types with associated thorium geology and thorium resources. It reviews available data on thorium occurrences/deposits and thorium resources and presents a classification of deposits according to geological and economic criteria.
[en] Member States have recognized the increasing need to model future nuclear power scenarios in order to develop strategies for sustainable nuclear energy systems. The IAEA model for energy supply strategy alternatives and their general environmental impacts (MESSAGE) code is a tool that supports energy analysis and planning in Member States. This publication documents the experience gained on modelling and scenario analysis of nuclear energy systems (NES) using the MESSAGE code through various case studies performed by the participating Member States on evaluation and planning for nuclear energy sustainability at the regional or national level. The publication also elaborates on experience gained in modelling of global nuclear energy systems with a focus on specific aspects of collaboration among technology holder and technology user countries and the introduction of innovative nuclear technologies. It presents country case studies covering a variety of nuclear energy systems based on a once-through fuel cycle and a closed fuel cycle for thermal reactors, fast reactors and advanced systems. The feedback from case studies proves the analytical capabilities of the MESSAGE model and highlight the path forward for further advancements in the MESSAGE code and NES modelling.
[en] The approach applied in the study is based on the internationally verified framework developed in the INPRO collaborative project “Global Architecture of Innovative Nuclear Energy Systems with Thermal and Fast Reactors and a Closed Fuel Cycle” (GAINS) GAINS project [XIV-1] includes 8 framework cases for Homogeneous and Heterogeneous (multi-group) world for high and moderate demand scenarios based on once-through and closed fuel cycle. The INPRO collaborative project SYNERGIES - Synergistic Nuclear Energy Regional Group Interactions Evaluated for Sustainability applies and amends the analytical framework developed in GAINS to model more specifically the various forms of collaboration among countries, assess benefits and issues relevant for collaboration and identify those collaborative scenarios and architectures that ensure a ‘win-win’ strategy to both, the suppliers and users. The GAINS framework classifies non-personified countries into three country groups according to their nuclear fuel cycle strategies: NG1 countries pursue fast reactor programme and perform recycling of SNF; NG2 countries either directly dispose of the SNF or send it to NG1 for reprocessing; and NG3 countries are LWR based newcomer countries that send the SNF back to NG1 or NG2. The analysis methodology in this study is based on varying the allocation of future nuclear energy generation share of each country group as function of time for assessment of different scenarios, in comparison to the GAINS studies where the NG1:NG2:NG3 ratio was kept fixed at 40:40:20. The sensitivity analysis is targetted on studying the behavior of global nuclear energy system shares in terms of its key parameters and stress limits under variations in country group. The GIANS studies were performed under fixed NG1:NG2:NG3 share ratio held at 40:40:20. This study explores possibility of transition of NG1 and NG2 groups under changes in NG1:NG2 proportion. The study also assesses impact of NG3 share variation on NG1/NG2 front end and back end fuel cycle requirements.The present study assumes high demand scenario established by the GAINS for nuclear power generation demand growth based on long term energy demand scenarios developed by the IAEA and IPCC. According to the adopted high demand scenario, the energy demand grows to 5000 GW(e).year in 2100 and flattens afterwards. The base case BAU-FR is considered with three reactor types namely LWR, HWR and FR (BR=1.0). Brief description of reactor characteristics used in the study is provided. The fast reactors are assumed to replace LWRs gradually upon introduction. The share of HWRs in nuclear energy mix is assumed to be constant at 6% and independent of FR introduction.
[en] Even though thorium is considered a sustainable fuel cycle option, owing to the abundance of uranium and its relative ease of handling, serious attention has not been paid to developing a commercial thorium fuel cycle. Recently, the focus has again shifted towards thorium utilization because of the favourable aspects of thorium fuel. Advantages of thorium include its relative abundance compared with uranium and its occurrence as a co-product or by-product of deposits mined for other minerals. Other benefits of thorium include the better waste profile of the fuel cycle and non-proliferation advantages. For these reasons, research and development activities are currently being carried out on several types of advanced reactor that can use thorium.
[en] This annex compiles the results of relevant French and Russian scenarios for closing the Plutonium cycle with the introduction of a number of fast reactors. The studies presented in this annex fall into SYNERGIES Task 1 on Evaluation of synergistic collaborative scenarios of fuel cycle infrastructure development. The objectives of the studies compiled in this annex are to address the problem of SNF accumulation from LWRs and to decrease natural uranium consumption based on possible closed fuel cycle scenarios involving the introduction of a number of fast reactors under development in France and Russia.
[en] The Nuclear Fuel Cycle Simulation System (NFCSS) is a scenario based computer simulation tool that can model various nuclear fuel cycle options in various types of nuclear reactors. It is very efficient and accurate in answering questions such as: the nuclear mineral resources and technical infrastructure needed for the front end of the nuclear fuel cycle; the amounts of used fuel, actinide nuclides and high level waste generated for a given reactor fleet size; and the impact of introducing recycling of used fuel on mineral resource savings and waste minimization. Since the first publication on the NFCSS as IAEA-TECDOC-1535 in 2007, there have been significant improvements in the implementation of the NFCSS, including a new extension to thorium fuel cycles, methods to calculate decay heat and radiotoxicity, and demonstration applications to innovative reactors.
[en] The objective of this contribution is to analyze long-term scenarios for closed fuel cycle in a European context, including economical estimates as additional reference results. The analysis of long-term sustainability of nuclear energy should consider transition scenarios from the current open fuel cycle or partially closed to fully closed cycles based on advanced technologies. This kind of study must provide answers to different aspects of transition scenarios, such as the period of time needed to reach material flow equilibrium, the recommended number and date of introduction of facilities in the fuel cycle, the amount of stored material, the nuclear waste, etc. Moreover, there is an interest to improve these studies with economics analyses, as a necessary input to evaluate the realistic viability of new strategies. This Annex analyses the transition from the existing light water reactor (LWR) fleet to advanced fast spectrum reactors, taking also into account an intermediate stage of Generation III+ LWR deployment. It assumes that a representative number of European Union countries is involved, as in the exercise PATEROS. The analysis of these fuel cycle scenarios has been performed according to guidelines specified in the EU CP-ESFR and ARCAS projects. The nuclear fuel cycle scenarios have been evaluated using TREVOL, a module developed by CIEMAT in order to improve the capabilities of the in-house burn-up simulation system, EVOLCODE 2.0. TREVOL has been designed to study short, medium and long-term options for the introduction of various types of nuclear reactors and for the usage of associated nuclear material, giving due consideration to the isotopic composition of the material in any stage of the fuel cycle, essentially uranium, plutonium, minor actinides and fission products. Moreover, the application of an economic module provides additional and relevant information to study the fuel cycle in a global context.
[en] There are different variants of organizing the closure of nuclear fuel cycle (CNFC) depending on fast reactor type, fuel types, station or centralized allocation of closed nuclear fuel cycle stages. Many processes and engineering solutions used for realization of chosen technologies for reprocessing spent fuel are little-studied. The mathematical modeling of radiochemical technology is used to verify and estimate engineering solutions. It will allow to optimize complex process technology in order to increase effectiveness and reduce cost. To achieve this goal within Project ”Proryv” the mathematical models of key technologies for reprocessing spent fuel, fuel refabrication and handling radioactive waste are being developed. The models are implemented to program complexes VIZART and COD TP. The main objective of this codes is to validate realizability and optimize parameters of processing lines of CNFC. The codes use integrated library of technology models and allow to calculate material balance, create sequence diagrams, determine the most loaded parts of processing lines, estimate accumulation of fissile materials in apparatuses and intermediate vessels, estimate the influence of control actions on technology process. (author)