[en] Nuclear energy has very good assets for the future: economic competitiveness, respect of the environment (no emission of greenhouse gas) and preservation of natural resources (breeding capacity). The main challenge concerns nuclear fuel cycle back-end that is the future of spent fuel but in fact all the cycle is involved because new reactor concepts and multi-recycle strategies can be defined to reduce the amount of high level radioactive wastes. Studies confirm that for an annual production of 400 TWh, it is possible to get a drastic reduction of radiotoxicity of wastes: of about a 3 to 5 ratio by multi-recycling plutonium, of about a 10 to 20 ratio by multi-recycling both plutonium and americium, of about a 100 ratio by multi-recycling plutonium, americium and curium. (A.C.)

[en] In France the complete closure of the fuel cycle can be reached in 3 steps. The first step relies on the improvement of the present fuel cycle by implementing the use of reprocessed uranium (URT) and by enlarging the use of MOX fuel from 900 MW to 1300 MW PWR. The first loading of URT fuel is planned in 2023. The second step will be the multi-recycling of plutonium. The loading of a test fuel assembly with multi-recycled Pu in a PWR core could be made in 2025-2028 and the industrial deployment may be made in 2040 at the soonest. The third step implies the development of a fleet of fast reactors that will allow a limitless recycling of spent fuels and no necessity of using enriched natural uranium. (A.C.)

[en] The Fuel Cycle Options (FCO) campaign in the U.S. DOE Fuel Cycle Research and Development Program recently completed a detailed evaluation and screening of nuclear fuel cycles (report available at www.inl.gov). The comprehensive study identified promising fuel cycle options that offer the potential for substantial improvement compared to the current U.S. fuel cycle. This paper describes insights from the study and the use of the results for current fuel cycle analysis activities. The insights obtained from the study prompted questions about the usefulness of minor actinide recycle and the relative potential of thorium-based fuel cycles compared to uranium-based fuel cycles. The FCO campaign is conducting analyses exploring these issues as well as the potential transition to such fuel cycles to identify the challenges and the timing for critical decisions that would need to be made, including investigation of concerns such as the effects of a temporary lack of recycle fuel resources or supporting infrastructure. These studies are part of an overall analysis approach designed to provide information to the U.S. DOE Office of Nuclear Energy decision-making process for R/D directions. (author)

[en] A recent Evaluation and Screening (E/S) study of nuclear fuel cycle options was conducted by grouping all potential options into 40 Evaluation Groups (EGs) based on similarities in fundamental physics characteristics and fuel cycle performance. Through a rigorous evaluation process considering benefit and challenge metrics, 4 of these EGs were identified by the E/S study as 'most promising'. All 4 involve continuous recycle of U/Pu or U/TRU with natural uranium feed in fast critical reactors. However, these most promising EGs also include fuel cycle groups with variations on feed materials, neutron spectra, and reactor criticality. Therefore, the impacts of the addition of natural thorium fuel feed to a system that originally only used natural uranium fuel feed, using an intermediate spectrum instead of a fast spectrum, and using externally-driven systems versus critical reactors were evaluated. It was found that adding thorium to the natural uranium feed mixture leads to lower burnup, higher mass flows, and degrades fuel cycle benefit metrics (waste management, resource utilization, etc.) for fuel cycles that continuously recycle U/Pu or U/TRU. Adding thorium results in fissions of ²³³U instead of just ²³⁹Pu and in turn results in a lower average number of neutrons produced per absorption (η) for the fast reactor system. For continuous recycling systems, the lower η results in lower excess reactivity and subsequently lower achievable fuel burnup. This in turn leads to higher mass flows (fabrication, reprocessing, disposal, etc.) to produce a given amount of energy and subsequent lower metrics performance. The investigated fuel cycle options with intermediate spectrum reactors also exhibited degraded performance in the benefit metrics compared to fast spectrum reactors. Similarly, this is due to lower η values as the spectrum softens. The best externally-driven systems exhibited similar performance as fast critical reactors in terms of mass flows, but they face much greater challenges, including higher waste generation and higher economic and development costs associated with the external neutron supply. Therefore, any fuel cycle option within the most promising EGs that include thorium in the feed mixture, involves intermediate spectrum reactors, or uses externally-driven systems will be less promising than the reference fast spectrum critical reactor with only natural uranium feed. (authors)

[en] Even considering the post Fukushima context, nuclear energy is a sustainable way to answer the worldwide increase in energy needs, while limiting green-house gas emissions. Future innovative nuclear fuel cycle options are needed in order to recycle valuable materials such as plutonium, and to better manage highly radioactive nuclear waste by burning minor actinides and particularly americium. This can be achieved by optimizing the current and future industrial processes through both engineering studies and high-quality basic research. Within this framework, this paper presents recent progress obtained at French CEA on the development of innovative actinide partitioning hydrometallurgical processes. Improvement of Pu mono-recycling in Light Water Reactors is related to the implementation of the U-Pu co-extraction COEX^TM process which allows a complete co-management of U and Pu within the fuel cycle, reinforcing the prevention of potential nuclear material diversion. Going further in terms of resource consumption efficiency requires implementing the Pu multi-recycling in Fast Neutron Reactors, with still needed process optimization. Concerning minor actinides, several processes have been developed in France since 1991 in the frameworks of two successive waste management Acts of the Parliament, and recent results of recovery performances obtained on high active conditions tests of the GANEX, SANEX-TODGA and EXAm extraction processes are presented and discussed. (author)

[en] A recent Evaluation and Screening study of nuclear fuel cycle options identified a few groups of options as most promising. One of these most promising Evaluation Groups (EGs) is characterized by the continuous recycling of uranium (U) and transuranics (TRU) with natural uranium feed in both fast and thermal critical reactors. This evaluation group, designated as EG30, is represented by an example fuel cycle option that employs a two-technology, two-stage fuel cycle system. The first stage involves the continuous recycling of co-extracted U/TRU in Sodium-cooled Fast Reactors (SFRs) with metallic fuel and breeding ratio greater than 1. The second stage involves the use of the surplus TRU in Mixed Oxide (MOX) fuel in Pressurized Water Reactors that are MOX-capable (MOX-PWRs). This paper presents and discusses preliminary fuel cycle analysis results from the fuel cycle codes VISION and DYMOND for the transition to this fuel cycle option from the current once-through cycle in the United States (U.S.) that consists of Light Water Reactors (LWRs) that only use conventional UO₂ fuel. The analyses in this paper are applicable for a constant 100 GWe capacity, roughly the size of the U.S. nuclear fleet. Two main strategies for the transition to EG30 were analyzed: 1) deploying both SFRs and MOX-PWRs in parallel or 2) deploying them in series with the SFR fleet first. With an estimated retirement schedule for the existing LWRs, an assumed reactor lifetime of 60 years, and no growth, the nuclear system fully transitions to the new fuel cycle within 100 years for both strategies without SFR fuel shortages. Compared to the once-through cycle, transition to the SFR/MOX-PWR fleet with continuous recycle was shown to offer significant reductions in uranium consumption and waste disposal requirements. In addition, these initial calculations revealed a few notable modeling and strategy questions regarding how recycled resources are allocated, reactors that can switch between different fuel designs, the modeling of early retirements of existing LWRs, and the impact of the SFR conversion ratio on the SFR/MOX-PWR energy generation ratio. (authors)

[en] The spent fuel reprocessing by dry process called pyro reprocessing have been studied. Most of U, Pu and MA (minor actinides) from the spent fuel will be recovered and be fed back to the reactor as new fuel. Accumulation of remain actinides will be separated by extraction process with liquid cadmium solvent. The research was conducted by computer simulation to calculate the stage number required. The calculation's results showed on the 20 stages extractor more than 99% actinides can be separated. (author)

[en] The purpose of the contribution is to explain the following points: (i) The choice of the Reprocessing Conditioning Recycling (RCR) policy means benefitting from a flexible technology in the medium term, with the possibility of a periodic review and fine tuning of the back-end flows and quantities (e.g. the plutonium inventory). (ii) Long term fuel cycle management in Germany is sustainable, on the basis of progressive multirecycling steps that will control the plutonium baseload inventory; from todays achievements, on can reckon such a scheme is confronted with no major technical limit. An attractive feature of the recycling scheme is to open the way to future advanced processes, such as minimisation of ultimate waste volume or partition and transmutation of TRU, if needed. (iii) The RCR policy is already cost efficient and well be clearly advantageous in the long run. To illustrate and quantify these points, an aggregated model of annual fuel requirements in Germany has been elaborated; it has been applied to the period 1979-2029, thus integrating past and future requirements. Some results are presented hereafter. (orig./DG)

[en] These proceedings contain ten communications of which nine have been separately indexed and analyzed for inclusion in the data base

[en] This paper examines the different plutonium recycling policies for the utilities in different countries. Countries' policies could be classified into three categories: 1)Countries with a Reprocessing-Conditioning-Recycling strategy (RCR) (include Belgium, Germany, France, Japan, Switzerland, UK, Russia.. 2)Countries storing the spent fuel and developing a program of Direct Disposal (DD) (mainly Sweden and USA) 3) Countries storing the spent fuel without having made an official choice on the back-end (Spain, Korea, Taiwan, China). The alternative ways in which plutonium can be used are at first summarized and the factors influencing decision making in each country are discussed. Factors considered are technical, economical, ecological, strategic, political and environmental. As a matter of fact, the RCR strategy provides a wide range of advantages particularly in the fields of energy strategy and environment. Indeed, it allows to 1)save significant amounts of energy 2)package the waste in a very efficient and safe way 3)significantly limit the radiotoxicity in the final waste. (O.M.)