 time for questions at the end. But please also interrupt me if there is any need for further clarification during the lecture. I appreciate that. I prefer that way. Now, it's not that far away. So I think that you still, more or less, remember what we were talking yesterday. We were talking of scenarios that Galenios afterwards did improve with the much more sophisticated approach of the improv. But we were talking of scenarios mostly. And we were indicating, at least in my presentation, the issue of the resource availability. One has certainly good principle reasons for the development of nuclear energy. But one has to cope with requirements, limitations, and to have an idea of what the real needs are. So this cannot be done not in a lecture or in a series lecture. So each of us has been choosing specific topics. And if you remember, yesterday, I was concentrating more on the availability of resources. Since it is probably one of the most strategic issues related to the development of nuclear energy. Today, I will be going in enlarging the perspective and going inside some of the technical issues that are hidden in a scenario study. And I will be talking in a very shortened way on possible options of the fuel cycle. And again, there, one can have to discuss a number, a very large number of issues that are associated with the fuel cycle that has proven to be one of the potentially weak point of the development of nuclear energy. But I did choose one which has been for a couple of decades and still today a central issue of the fuel cycle and it's the management of waste. I think that all of you that are aware of the issues, policy issue, public opinion, interest issues, et cetera, know that the waste management is a key request for an optimized strategy practically in all countries. So I will be giving the focus on the waste management. And again, there has been a flourishing of options, different studies in the 90s, 80s, 90s, and the number of options that have been looked into associated to the fuel cycle have been extremely numerous. Every laboratory, every research group had its own view on how to handle the fuel cycle, how to manage waste, and using different type of reactors. I will be putting my focus on fast reactors since it has been considered one of the major and most interesting option to provide the optimization of the waste management. I will just flash on a number of more recent proposals or revivals that will be taken back by some of my colleagues here lecturing to you later. So waste management and focus on fast reactors. These are the two key words of my presentation today. Now, I have to remind you a few very basic notions related to the fuel cycle just to have clear what we are talking about and we have a common language. If you have to put question and for me to describe specific issues of the fuel cycle, I've been starting with a number of very fundamental ideas of the fuel cycle. Now, what is written in the second bullet is the key point. The fuel cycle provides the mass flow infrastructure that connects the energy resources of uranium and thorium or through the nuclear power plants to the eventual waste management of the overall nuclear energy enterprise. So the fuel cycle includes from the mining down to the disposal of waste. Reminding you that when we are talking of natural resources, yesterday I was mainly focusing on the natural resources that are at the basis of the fuel, so the uranium or thorium. But there are the construction materials and other renewable resources. Here the water for cooling are part of the fuel cycle. And the waste is a very general word that includes both what is the waste at the mining from the mill tailings, for example, which is a not negligible issue, the depleted uranium. The spent nuclear fuel that one has in mind that when you talk of waste, you focus on the spent nuclear fuel. And the high level waste, which could be released to the environment. And of course, there are a large amount of non-nuclear waste. De-waste management is a complex issue. And in most of the country where there is a sizable amount of nuclear power, waste management agencies have been set up in the last 20, 30 years, recognizing the need of a specific authority to handle this issue. Now, these are very generic that you can read on the newspaper. Let me go a little bit more in detail and giving to you a very, again, simplified picture, but a picture of what looks like a fuel cycle. Again, things that you probably very well know. But let me remind in terms also of language. Well, the starting point is, of course, the mining with what is the conversion facilities. You don't get straight away, as you know, the material ready for be putting in any reactor. But you have a problem of conversion of, for example, the uranium ore. And in this process, you are producing tailings. Now, the second facility or block of facilities in the fuel cycle are related to the enrichment. I'm talking of uranium. And as an example, so the enrichment is what you would expect in thinking of PWRs, enrichment from the natural enrichment of uranium 235, two of the order from 3 to 5 according to the level of development of the PWR you are thinking about, and the level of burn up that you want to reach. You will be left with depleted uranium. And both of them will be going to what is the step of the nuclear fuel fabrication. If you have reached the uranium, you will be using as such to fabricate PWR type of fuel. If you are considering the depleted uranium as part of the fuel, it is because you have in mind the fabrication of mixed oxide fuel bearing plutonium for fast reactors, but also for light water reactors. Now, all of that, this is the fuel fabrication step on which you will hear much more from each be a sun for specific cases later on in the day. And while the fuel rods are transferred in a simplified way, but they are transferred to the reactor, which is the fourth step of the fuel cycle. The reactor is, in a modern view of the fuel cycle, one of the steps of it. The reactor will produce in electricity, of course. And at the end of the day, it will be producing used fuel, spent fuel, irradiated fuel, whatever you want to call it. And there is a step which is of very high relevance, in particular to assess the policy and strategy of a country, how to store all the spent fuel close to the reactor elsewhere. You have to cool it for some time. Decay heat is an important issue in thinking of the storage of the spent fuel. Now, after storage, you have the real key question that shapes the overall policy for the fuel cycle. Would you be sending after an appropriate period of storage cooling it down, for example, leaving it decay? Would you send it directly to a disposal? Or you go to a step of reprocessing and re-injecting the reprocessed fuel, in particular, take the case of the uranium cycle, take the case of the re-utilization of plutonium, re-injecting the plutonium coming from reprocessing for associated with the depleted uranium, fabricate box fuel, and so on. Reprocessing, of course, will also mean that you will be left with some reprocessed uranium, reached, for example, in uranium 236. And you will have also to handle with a number of waste that are coming from the reprocessing operation. And again, the step of the disposal will handle with particular facilities, I'm indicating here only the possibility of vitrifying waste will be sent to the last step in this very broad view of the fuel cycle. So it's a complex operation of the fuel cycle. It does imply that this is the sense of putting that on the cartoon to give you the sense that there are a lot of facilities that are involved in the fuel cycle. And it depends, in part, from the fact that we are mostly using solid fuels. You will have a specific lecture on molten soils. And you will see that some simplification and some more complication of this fuel cycle can be obtained if you think of fuel in a different form, in a fluid form, for example. Now, having said that, and having even at least the nomenclature principle that I will be using, let me go to a number of choices for the fuel cycle. And reminding that the choices of the fuel cycle as of the reactors that are associated, the reactors being one of the step of the fuel cycle, they have to meet the number of requirements that Gaina was indicating yesterday, essentially the sustainability, of course, safety, and the economics. You have seen yesterday plenty of examples with a very large number of criteria, evaluated the criteria in different perspectives. But the essential point is that you choose a nuclear agency will propose to its government in their country a strategy for the fuel cycle according to the requirements that comes from the government or the politics and, in a sense, from the public opinion, in terms of sustainability, the safety that is associated to the fuel cycle, and of course, from the overall point of view of the economics. Well, I single out what most of you know very well, the four major options for the fuel cycle. One is the once-through, which is the dominant strategy today in most countries that have been developing nuclear energy, the pioneer implementation of nuclear energy, for example, in the United States, ended up, even today, using the once-through option. The fuel is fabricated, for example, from uranium. It irradiated the stored to allow this reduction of heat, leave it decay, and then directly disposed as waste. Lightwater reactors, for example, in the U.S., as I indicated there, use this type of fuel cycle. This is very, very much used, and it was the option that at the very beginning was considered as the standard one, waiting for better options for the fuel cycle, let's say. This was the strategy of the 70s when there was a big expansion of nuclear energy in many countries. In the late 80s, there was a revival of interest by policymakers and in the public opinion, saying, well, we are storing a lot of irradiated material. What is its future? What is the legacy that we will be leaving to future generations? The second option is also underway in some countries where there is an important share of nuclear energy. And for this option, a fraction of the spent nuclear fuel is processed, and the fraction of it is recovered and new fuel is fabricated. And this fuel is returned to the reactor for going back in the irradiating one or two times. This is what is done, for example, we are not far away from France. This is what is done in France is an option which is not a final one, but already implies a step towards a more radical type of fuel cycle and is also a way of demonstrating the feasibility and the performance of facilities for treating the spent nuclear fuel. The third option of the fuel cycle is certainly the more ambitious type of option for the fuel cycle is the full fissile material recycle. Now, all the spent nuclear fuel is reprocessed and the recovery of plutonium, I introduce here the fact that if you were using thorium or trying to deploy a thorium-based system, you will have to reprocess to recover it, you're ready to 33. And the idea is to reuse the material that is recovered and reuse and reprocess several times, taking as waste only what is not directly considered as a worthwhile fissile material. So the so-called binauractic and so the isotopes that are higher in mass than plutonium isotopes and the fission products. And this is what was traditionally thought to be the fuel cycle to associate to the deployment of fast reactor. So recovering all the plutonium or the uranium 233 and taking as waste all what is lesser or higher mass actinized and fission products. This is the third option. It's not implemented anywhere. It has been the dream, more or less, of the late 70s to go as quick as possible to this type of fuel cycle in particular area of the world, where there was a very quickly, very rapidly expanding economies. And where there was a kind of strategic need to provide the insurance of the availability of energy sources at the time there were political instabilities and even wars related to the availability of oil. For example, you are too young to remember, but the 70s were very troubled years in these terms. And the dream of going to this option of the nuclear fuel cycle was very seriously considered, even not only at the level of a scientist, but in particular the level of policymakers. Things have been changing during these years and has not been implemented this option anywhere yet. At the end of the 80s, it became clear that there was one more issue, not only the availability of resources in different areas of the world and secure the availability of these resources at any time. There was also the growing concern about the waste. And the fourth option of the fuel cycle that I call here full actinide recycle was very much considered, very in depth considered, in which all the spent nuclear fuel is processed and all the actinides now, not only in plutonium or uranium 233, but all actinides are multiply recycled. There are, of course, as I said at the very beginning, this is a view that I give to you, which is relatively simplified to have in mind that the four major options inside this one, for example, there are tens of different options. But it's a class of fuel cycle option. There are, apart from these four major options for the fuel cycle, there are many other options that are available, in particular, for example, that have been imagined a way of doing a better utilization of the uranium, avoiding recycle. And I will spend three minutes and one transparency reminding to you the traveling waiver reactor concept that has been, is being studied in the US in the frame of the initiative that comes from a very well-known person, Bill Gates. So other options are available. I will be mentioning two or three of them. However, I would say that, still today, these four major options is what you, personally, I think you should keep in mind as the real alternative. Afterwards, they are multiplied in several possibilities, organized in several ways, according to the criteria that you use in optimizing the fuel cycle. Galina has been showing that very nicely yesterday. But essentially, these are the four major options for the fuel cycle. Now, a cartoon. Instead of words, this is what if you have to give an image of a fuel cycle with there is a partial, let's say, reprocessing. This is what you will be indicating from the assembly that is a PWR assembly spent fuel. You will be getting, and I hope that the colors are enough to see the numbers here because these are the order of magnitudes that you should probably have. This is an assembly of a PWR where what you will get is a large part of it will be still uranium, 94%. And plutonium will be of the order after a normal burn-up in the history of irradiation. The plutonium accumulated will be of the order of 1%. And the other radianuclides are of the order of 5%. So this is the order of magnitude. I would say that one has to keep in mind. And for this spent fuel that is sent to reprocessing for plutonium recovery, this is a game in this cartoon you have the indication of the flows that you will be getting, which is more complex than say, well, there is plutonium and other radioactive nuclides. I think that apart from uranium and plutonium, one has to consider, are there gaseous effluents? Yes, there are. Because they need a specific approach for the treatment. There are liquid effluents, in particular the tritium and some of the fission products. A number of impurities, which are activation products. And there is a number of these fission products, structure-activated products, binoracted as impurity, et cetera, that will be ready to be put in a particular form for being treated as waste. So there are streams. The idea of this cartoon is just to give you an idea. Of course, it's not enough quantitative. But to give you an idea that we are talking of several streams of materials, apart from the product that we want to recover to re-inject in the fuel cycle. This is part of the complexity of the fuel cycle. And this is typically associated to the solid type of fuels. You will be indicated in the lectures. I don't see him in the room. Professor Buris will be talking of your molten salts, which is an option for which this scheme has been modified in a relatively substantial way. Now, if we want to concentrate, having said that in general, and we want to concentrate on the most innovative fuel cycle associated to the innovative option for nuclear energy, which is the core of what we will be talking in this workshop. And again, having the focus just on waste management inside the ones that I've been indicating before the fore and the excluding, of course, the ones through. We have three other major scenarios for implementing what is called partitioning and transmutation. You have seen that most of what I'm talking of reprocessing, all the options starting from partial reprocessing to full reprocessing of fissile or all arctinides. What I'm talking about is to make a selection. And this was the meaning also of the previous slide. Well, there are products that I'm ready to reuse, and there are a number of flow-saw material in the overall operation. I'm partitioning in terms of chemistry. I'm subdividing. And I try to reuse after having partitioned to reuse to transmute a number of the isotopes that have been recovering. This is the sense of the terminology that is indicated there that I'm pretty sure all of you know very well. Now, as I said, well, at that point, I can be more precise because there have been a number of interesting and important proposals in the past. And I figure out again to summarize a very large number of options and studies that have been made in just three categories. The first one is what I would call in a terminology that is very similar to the one that has been used by Galena yesterday. The sustainable development of nuclear energy with waste minimization. These are the keywords. I want to be sustainable. So I need to have material available to continue the operation for the long term, and at the same time, I want to minimize the waste. The ideal solution for that is to use one type of reactor, one fuel type, and one unique reprocessing process, which is associated to the fact that I can separate the overall amount of transuranic elements, the TRU, which is indicated here, and homogeneously recycling in a reactor. This is not only an academic view. It can be associated to a specific type of fuel. Metal fuels, as developed, for example, in the United States, in principle, offer the possibility of going towards this type of innovative fuel cycle. It has not been demonstrated fully, but it's one possibility with strong argument to make it feasible. There is the second option. There is this saying, well, the first one is very radical, because it means that all the reactor, all my power park is made by one only type of reactor that does everything. Handles the spent fuel. Waste is no more the word that I will be using for the first step, but only as a partial step. We will see in a cartoon in a moment. The second option is less radical, and this is closer to what are the industrial view of the overall fuel cycle. The industry would like to have separated a stratum, a part of the fuel cycle dedicated to the production of energy from another fuel cycle where I'm handling the one that will become waste if I do nothing. This was an idea of, and it's called double strata, that was initiated in Japan, and in particular by a very important researcher, Mukayama-san, that did, I think, if Ichimiya-san agrees, gave the name of double strata, I think, or it was in its environment that was given. I think it was an extremely important idea, separating, as you see here, the commercial reactors with plutonium utilization, what will be the part where the industry is mostly interested from a stratum of the fuel cycle, where there is the minor actinite management, and there's more the endeavor of a government in energy policy directory, in a sense. So two separated fuel cycles. This is an option. You will see, while here, there is this homogeneous full TRU recycling in all of the reactor, only one type of reactor. Here, we have two separate fuel cycles. The objective is the same, but one is separating the functions in the fuel cycle. Now, these two scenarios imply the continuous use of nuclear energy, the stabilization of the transuradium stocks in the fuel cycle, and the minimization of waste in the repository. So there are important words in this sentence, because it means that one is looking to the utilization of nuclear energy in the long term. One is preparing infrastructure that are able to provide a sustainable source of energy in the very long term, so a continuous use of nuclear energy, stabilizing the amount of transuranic and minimizing waste. Now, the third option is, on the contrary, something that has been associated to the idea that, well, I have to be able to reduce the transuranic stocks. Instead of stabilizing, as it is the purpose of the first two options, instead of stabilizing and having the possibility of continuously using nuclear energy, the third option says, well, let me cautious about that. We have reactors that are producing transuranics. We have to have a fuel cycle that is able to not to stabilize but to reduce drastically the amount of transuranics available, because there is a change in policy, the discovery of new energy sources, new options to be considered in the country, the growing interest for renewable that are not nuclear, for example. And we have to be ready to have a fuel cycle that can provide a solution and not leaving transuranic all over the earth unprocessed. So the third option is, yes, the continuous use of nuclear energy is on a probably limited amount of time. And we have not to leave legacy, important legacy in terms of transuranic. And however, what these three, despite the different option, you see, here is a very ambitious option. The second one makes already a distinction for what is the responsibility of the state, of the state to the responsibility and the goals of an industry. The third one is having a very cautious policy towards nuclear. However, all these scenarios go very much beyond the strategy of the one through, the so-called open fuel cycle, in which there is a final storage of only irradiated fuel. And all of these, including the option number three, the most cautious one, imply the reprocessing of the fuel. Now, three cartoons to show you what are the flow of masses in the three scenarios. The first one, as I say, is the sustainable development of nuclear energy for electricity production, together with the waste minimization. Now, the classical view of this type of scenario is to use a homogeneous, not separated, transuranic recycling in critical, fast reactors. As I said, this is not the view of the mind that I'm selling to you, but this is something that can be associated with the real fuel cycle. And I don't know if Ichimiya-san probably he will be touching a little bit of that. Anyway, the metal fuel allows to, in principle, to go towards this option. The fuels are all standard mixed oxide, or dense fuel, metal, nitride, and carbide, with a minor actinide content of a few percent, definitely less than 5% to 10%. You remember that when I did show to you the amount of material that is in the spent fuel, there was a 1% of plutonium and the 5% of a mixture of minor actinides and fission products. Fission products are the dominating part. And the overall minor actinides in the spent fuel is of the order of 0.1%. So 1% plutonium, 0.1% minor actinides, makes the homogeneous mixture containing no more than in between 5% and 10% of minor actinides. This is important, and we will see in what follows. One can even imagine of doing, it has been imagined that I feel the need of mentioning that not only this very nice simplified approach of having all the transuranic homogeneously recycled in a fast reactor and giving rise to reactors like this one, which you see a classical section on the midplane, but also one can imagine of having the overall minor actinides put in targets inside the reactor and recycling everything, plutonium as part of the fuel and the minor actinides as part of the targets. This is technical details just to tell you that there is not only one way of thinking of that, which will make scream a lot of people that have been developing the heterogeneous mode, to tell you that, well, this approach can be even modulated somewhat. And here is what is the result. What you have to think is you start from the PWR with the standard York's fuel. There is some cooling time, of course. Afterwards, you have the step of reprocessing, where there is important is the decontamination factor. How much will I be recovering 99.9%, 99, or whatever? There will be a number of secondary waste that will be produced. There are problems, of course, in doing this operation of avoiding criticality phenomena. And what is being considered as really waste, the official products and the losses, I will not be recovering 100% by 99.9%, as it is done at La Hague in France, recovering plutonium, probably. Anyway, there will be losses at reprocessing plus the official product. They will go to the repository, while the plutonium and minor actinates will go to a step of fuel fabrication that will be injected in a fast reactor. And again, a different type of reprocessing with respect to this one will be put in place. And again, I will have to look in recovering as much as possible, so optimize the decontamination factors, minimizing the secondary waste and avoiding criticality. And again, I will continue this way. And this reprocessing step, official products again and losses at this type of reprocessing will be getting to the repository. So you see, this is the ideal system that is being conceived, where the repository will go only official products and the losses at the reprocessing, while the key issue that will be at the fuel fabrication, because we will have this amount of minor actinates. Now it's 10% of the overall fissile material plutonium. Remember, if it's 100, this will be 10, more or less, in between 5 and 10. So among these minor actinates, I'm not separating. I'm keeping them, all of them. There will be guys like the Californium 252 that every one of you, I think, know, because this is a neutron source. But if it's a neutron source, it's not very nice to have it in a spent fuel, because this neutron source will be affecting the operation of fabricating the fuel. So the fuel fabrication with a lot of minor actinates is not an easy step. There will be this problem of the neutron source that you will see in a moment. I will be indicating to you that the fact of having potentially a very strong neutron source has killed very important options of partitioning and transmutation. There is the problem of the decay heat. Again, if I have a radioactive material there, alpha emitters, gamma emitters, I will have an important decay heat that I have to treat before fabricating the fuel. And I have also a promise of controlling the process. The americium is not that stable. I have to cope with the volatility of americium. And are the minor actinates easily missable with the rest of the material and the support, the matrix on which I will be putting all of them to fabricate the fuel? It's not at all a very simple and evident problem. So despite this fact, I will have problems at the fuel fabrication, certainly. And this is probably one of the key and difficult point of this option, how is fabricated the fuel. And I will have to optimize the reprocessing steps in order to send the repository a minimum amount of radioactive material to cope with my requirement. I want to have a sustainable development of nuclear energy and waste minimization. Now, the second option, you remember, it was the two strata of the fuel cycle. And here is how one can represent them. Now, in this scenario, there is the idea of eliminating as much as possible the minor actinate inventory, which is a pure waste management objective. Now, to reduce drastically the minor actinate inventory, I have separated the plutonium in order to have a stratum of the fuel cycle where I am in the industry oriented. I produce energy. And now I have a different stratum of the fuel cycle where I have to handle minor actinates, for example, to minimize the waste. Now, what is the type of reactor? It's no more the case of having only one type of reactor here, but apart from the lead of separating plutonium from minor actinates together, with the principle should be kept together. I can even think of separating curium from the other for specific reasons that I would say in a moment. However, there is separation of plutonium from minor actinates. Now, to maximize the consumption. Now, the objective is not only to produce energy in a sustainable way, but also to minimize waste. I have to use a specific type of reactor, a reactor which is loaded with a fuel which is free from uranium. Otherwise, I will not do a good operation. Because if I put uranium there, I irradiate, I will reproduce plutonium, of course, but again, minor actinates. So if I think of uranium-free fuel would be a good idea, at that point I have to imagine a type of reactor that is possibly working with this weird type of fuel in a kind of safer plutonium banner. And they have been very popular 20, 10 years ago and maybe still somewhat now. And there is someone in the room working on one of the projects of this type in Europe. The use of subcritical systems. This is a fuel uranium-free with a lot of minor actinates in that in which I have to deal with different type of reactivity coefficient and behavior in the reactor. So it will be prudent. It will be cautious to go towards a reactor which is subcritical with this type of fuel. So to be subcritical and sustaining the neutron chain, I will need to have an external source. So why not providing that to using protons against the target that produce neutrons. And this neutron will be the source for a subcritical system. This is all what is underlined by this sentence here using in this separated stratum of the fuel cycle a uranium-free fuel, so-called inert matrix, in an external neutron source-driven system with conversion ratio zero. So I will not reproduce any new fissile material. If this is a too drastic option to use this accelerator-driven system, no one is existing today in real life except a few experimental facilities. One can think of a critical burner-fast reactor. I have to burn the minor actinates using a conversion ratio which is much less than one, still acceptable, and this can also be envisaged. So all of that, if you translate that in an overall cartoon, again, you stand from the PWR loaded with your radium oxide. You go to the reprocessing step exactly as before. Now you will be recovering plutonium and minor actinates. Remember, before they were together, now I'm separating them. And what will go to the repository are fissile products and the losses at this new type of reprocessing. This new type of reprocessing, plutonium goes to the fuel fabrication that one can feed in the MOX PWRs, for example, and what will be reprocessing it in a step which is different from this one. This was to process the UOX fuel. This will be to process the MOX fuel. In reprocessing, one will go towards the fuel fabrication again for multi-recycling of plutonium in PWRs while fissile product that losses at the reprocessing as in the previous step go to the repository. Now, what about the minor actinates? The minor actinates separated, as I said, I want to eliminate as much as possible. I have to fabricate the fuel. And again, I'm indicating here that it will not be a very easy task because of the neutral source, because of the high decay heat and the process control due to the property of the different minor actinates. Fuel fabrication to be put inside a dedicated transmitter. Is it an ADS? Is it a critical fast reactor with a very low conversion or whatever it is? After irradiation, I will have to reprocess to have a multi-recycling of minor actinates and probably some plutonium, of course. And again, from this reprocessing, I will have to take all the fissile products and losses at the reprocessing to set at the repository. So you see, again, I'm obtaining at the end of the day the same result that I was obtaining in the previous approach. But now I have an industrial-dominated fuel cycle that is essentially made by modern advanced PWR, the loadies of plutonium, for example, in them. And I have a totally separated fuel cycle in which I'm trying to destroy as much as possible with the multi-recycling of the minor actinates. And to the repository, there will be a limited amount of radioactive material going there, fission products, as always, and losses at the reprocessing at these different steps. You will see that the fuel cycle, as I'm presenting the previous option in this one, makes use of a number of facilities which is relatively impressive. You remember yesterday, I indicated to you that one of the key problems in going towards a sustainable development of nuclear energy and not being limited by the resources, one has to put in place fast reactors, for example, and fast reactors means reprocessing. And here you have, at least on these very simplified images, the idea that I'm talking of a lot of important and large facilities with a number of very challenging issues to be solved. Now, this is the third scenario. The scenario, remember that I'm very cautious about the future of nuclear energy. And I want to have an option to be able to get rid of transuranics, not only of minor actinides as before, but the overall transuranics in order to be on the safe side in terms of decreasing, for example, the share of nuclear energy in an energy mix. Now, the ratio of the bioractilide to plutonium as indicated before is of the order of 10%. You remember I said it between 5% and 10%. And the group, the recovery of transuranic without separation of plutonium from bioractilide, if I want to reduce plutonium and minor actinide, I don't want to get the plutonium back to continuously use nuclear energy. But I want to be sure that I have an option to reduce drastically all of them. I have not to separate plutonium from minor actinides. Now, to maximize consumption, again, using as much as possible a uranium-free fuel, not to, if I have a uranium, I reproduce plutonium and so on. So maximizing the consumption means as much as possible a uranium-free fuel. And again, as I said before, this is a weird fuel with different characteristics of our reactivity coefficients and so on. An external-driven source system like an ADS will do the work. Or maybe, and this has been studied extensively, a burner critical fast reactor with a conversion ratio of 0.5 or less. And again, if in the double-strat approach, this was essentially to reduce the amount of bioractinide to minimize waste. Now I'm applying it to the overall transuranics to reduce them and to facilitate, if needed, a drastic reduction of the share of nuclear energy. Now, how does it look like in terms of a cartoon as before? Here I have the UX and the partly box, eventually, PWR, so with the reprocessing. And again, in the reprocessing, I will get uranium somewhere. Plutonium and minor actinide not separated. And losses at reprocessing and fissure products that go to the reprocessing. Now, plutonium and minor actinide go to the fuel fabrication with a number of issues which are always the same, of course, fabricating this fuel, putting them in dedicated transbuters that can be the accelerator-driven system, fast reactor with a very low conversion ratio, or even, and I will say half a word on that, there has been proposal, there are still being studied hybrid fusion fission systems. If I put this type of fuel inside the transuranic now, fuel in this dedicated transputer, I will have to reprocess because it will not be possible to reduce the amount in only one cycle, in one irradiation cycle. So reprocessing, recovering all the plutonium and minor actinide going back to the fuel fabrication and multi-recycling that. But now I have no more options when I will be reducing the amount to a level which is too small to be thought to be fed in the standard transputer. So I have certainly added the case in which I have to think about when I will have reduced the amount and I cannot any more make use of the same type of transputer here. I have the problem of envisaging a last transputer issue. So you see, in this case, what I'm doing, well, I say, well, for the moment, I will be continuing with the use of nuclear energy. But I'm ready to have a fuel cycle and the appropriate machine, the appropriate installations to get rid of all which comes out from the spent fuel. No more putting it in the repository. In the repository, there will be only limited amount of radioactive material. And I will have this fuel cycle costly, of course, but able to get rid and to reduce the burden on the repository. This is my half word on the fusion fission hybrids. Well, this is a cartoon that has been set up together the publicity of this hybrid system, which are an idea which is probably complicated to be implemented. But the principle is very clear. You have now the new source instead of coming from the spallation of protons on a target, come directly from the 14 MEV neutrons produced by fusion. And one can imagine and has been imagined and designed in several parts of the world, China and US, elsewhere, a system that can have a blanket where the transuranics to be transmuted will be put. So this is a sketch. When you go to the practical implementation problems, there are a number of implementation problems that are probably not impossible to solve, certainly difficult from the engineering point of view. Now, what are the potential benefits of doing this innovative fuel cycle in which one wants at any price, practically, to reduce the amount of waste? Well, the potential benefits are of at least two categories. One is the reduction of the so-called potential source of radiotoxicity in a deep geological storage. Whatever is the intrusion scenario inside the repository. This intrusion scenario, by the way, I'm well considered by the safety authorities. But if I reduce this potential source of radiotoxicity, I have done the right thing for the future. And the second point is the reduction of the heat load and the high level waste volume. Heat load and waste volume means a repository that will be limited in space. And if these measures are taken and these results are obtained, these two reductions, there is very probably that if the transuretics are not separated, for example, the homogeneous recycling in a fast-duty reactor, remember the scenario number one, the good result could result improved proliferation resistance. Now, the results of impact studies have been made in the US, in Japan, in Europe. However, still today, it's a debated issue between the P&T and the waste management communities, which are the good metrics. When the operation that has been done and that will be costly, what will be the results? How can we measure the performance of all these operations that imply the development of so many facilities? And the specific type of reactors. How we measure the benefits. Comparative analysis has been performed by the OECD there. Results are available. Any one of you interested in that, there is a large literature on all of that. What I wanted to say to you, well, there are potential benefits as indicated there. But the impact and the evaluation of the benefit is still a debated issue. Now, first of all, the radio toxicity of the ultimate waste. This is a classical graph that you have seen certainly previously. If you put in a repository the spent fuel and you leave as it is, the radio toxicity, which is related mainly to the radioactivity or the different isotopes, times, a factor that gives the potential toxicity of the specific radioactive element if you have ingestion of it. So it's a radioactivity essentially. This will be decaying with time. Here look the scale of time. This is one million of years. And this is the radio toxicity of the original uranium ore. Suppose that you will be using uranium at the mine. This is the normalizing value here. You will be reaching the one, the radio toxicity of the original material used to fabricate the fuel to produce energy. You will reach the original value just after the order of several hundred thousand years. Now, if you take out the plutonium and you recycle plutonium, you send to the waste only mine or active the official products. This is the second curve. Well, there is an improvement which is very sizable with respect to this one. However, one will have, one will reach this if it's a good metric or a good parameter to look. One will reach the original material radio toxicity after all the order of 10,000 years. And only if one uses the idea of eliminating also as much as possible binaractinites as in the double strata type of approach or the first scenario that I was indicating before. Only then you will be reaching the radio toxicity of the original material, the uranium ore, after a few hundred years, which makes this scenario attractive theoretically and in particular in front for a discussion in public. This could be an interesting issue and an interesting parameter to be put forward. Now, in terms of the heat load reduction, there was an interesting US study that was able to indicate what order of magnitude will be the reduction of the heat load in a repository if I reduce the fraction of, for example, of cesium strontium from the original value down to 1 per mil or if I reduce the fraction of transuranic plutonium americium and curium from the original value down to 1 per mil. And one sees that if one applies all the type of reduction, both of cesium strontium that are radioactive in the short time but very strong gamma emitters. And if one reduces drastically with partitioning and transmutation, for example, the amount of transuranics, and if one does both reductions, one reaches reduction factors of the order of 200 and which means volume reduction factors which are very, very sizable. Similar studies have been made in Europe and Japan and the conclusions are very consistent with them. This is another way of looking to the problem of the heat load which is an important one and to look instead of having a picture at a particular moment as it was in the previous slide, to see the evolution in time. And again, if one does nothing, this is the black curve. It is the heat load that will be reduced from the 10 years after the, I will put the, this, the spent fuel in the repository down to million year. And you will see that the reduction is there because of the activity, of course. But the heat load will remain fairly sizable for a long period of time. If one does the operation as I indicated, recycling plutonium, nothing done on minor actinides, there is an immediate benefit. But after that, there will be a long time in which the minor actinide presence in the waste will continue to give contribution to the heat load. And only if one does the full operation of eliminating minor actinides, transmuting them together with plutonium and leaving only fission products, one has this curve here that provides a reduction of the heat load of factors of more than 100 in more, little more than 100 or 200 years. So this is the example of the potential benefits. But how, what is the price which is paid in doing all of that? Again, I'm summarizing in one slide what has been the work of tens of laboratories over decades. So this is a very condensed and one specific type of result that I will be showing to you. There are feasibility issues. Not everything is that nice. Not everything is a question of finding the good metrics to measure the benefit. It's also the question of practical problems related in particular to the fuel fabrication. This special fuel with a lot of minor actinides included in that, pause problems. And here is a table that gives the decaying heat and the neutron production after posterior radiation cooling. So when one is thinking again of the fuel fabrication, you remember this is again my picture of the beginning of the lecture. And here you have the fuel fabrication where you have this amount of minor actinides to be put in the fuel to transmute it. And here there are a number of options. So there is the reactor type, the fuel type. And here is the potential increase in decay heat and neutron source. So the reference case is a PWR with MOX fuel. And so plutonium, it has only plutonium. This is a PWR recycling plutonium. And this is my reference. Now think of a PWR in which I want to homogeneously recycle transuranic. All what I've been showing to you was multiple recycle or transuranic in a fast reactor. And I did tell you, and there is problem if you do that in a PWR. And here is the problem. If you do that, you take all the transuranics at reprocessing and recycle all of them, not only the plutonium. Well, you will be increasing the decay heat and fuel fabrication of a factor of 3. But look what is the increase of the neutron source. It's approximately 10,000, the factor of 10,000 increase. And this is caused by the accumulation of the californium 252. And this, again, was pointed out very early in this study. And this was a killing point for any serious proposal of multi recycling transuranics in a PWR. No one is thinking seriously of putting minor actinines inside a PWR unless one think of an even more complicated strategy of taking out curium, storing curium somewhere, and multi recycling the rest. If one is serious about this P&T partitioning and transmutation strategy, this type of issue will make extremely difficult to implement this option. Now, let's go to fast reactors. If there is only plutonium, like for a PWR, it's even less decay heat at the very operation of fabrication. The neutron source is approximately as it is in the PWR. Now, let's take the option of the scenario 1. You remember, homogeneous transuranic recycle, minor actinine to plutonium ratio of the order of 10%. And I'm doing that with a fast reactor with a conversion ratio equal 1, a breakeven type of reactor. Now, there is an increase of the decay heat. There is an increase of the neutron source. But of the two orders of magnitude, the less important to the PWR, this is not a little issue. This issue makes utilities scream. And this was one of the initial point of resistance of many important utilities to any operation of partitioning and transmutation. If you will give me afterwards a fuel that will be at fabrication having these properties, I will have problem in doing that at the industrial level. Now, if we go to the other, you remember the other options were to homogeneously recycle transuranic to reduce them, conversion ratio, for example, 0.5. It's not an ADS, but a fast reactor with a very low conversion ratio. And now, I'm having a minor actinine to plutonium ratio of approximately 1. Remember, I take everything which comes out and I have all the accumulated minor actinine to eliminate. In this case, if I want to eliminate this type of a mixture, I will have to face the fabrication in a very strong increase of decay heat, approximately, in fact, 40. And the neutron source, which is more or less what I've seen in the case of a PWR. This means that if one wants to eliminate transuranics, one has to be very careful on the minor actinine to plutonium ratio that can be envisaged in order to make some feasible approach to the fuel fabrication. So these are the type of issues that are related. This is one example, of course. There are many more than that. There are many more related to the real metallurgy of the fabrication of these fuels. But these are just the consequences that you can see in an easy way that makes conscious about the possibility of implementing one cycle or another. This is a kind of complement to the kind of criteria that you were shown yesterday. When you go really to the real life and you make the detailed calculation, options that were looking interesting on paper, on a scenario study, can be give rise to problems like these ones. And this is killing points for any proposal. Now I will be quick in giving you a number of ideas on alternative fuel cycle options. I indicated here three, the use of molten salt reactors. I will limit that very much since you will get a lecture on that. The deployment of small modular reactors, just a word, and the option to make a better use of uranium without recycling the traveling wave reactor of terapower. Molten salts, they are all what I'm saying to you. This is an option that you will get much more of what I'm saying, of course. Let me remind you that starting from since 2005 in the carbon generation 4, there has been a very strong revival of the idea of deploying a molten salt reactor that had a lot of interesting features. And in particular, there has been a generation for the concentration of interest on fast spectrum molten salt reactors to get the generic benefits of fast neutral reactor, to extend the resource utilization and waste minimization, and getting also the features that are the interesting features of molten salts, low pressure and high limbo and temperature, optical transparencies. And all of that related to a reprocessing online of the fuel. You will get much more on that, but just to remind you that there are options beyond the one that I was indicating to you that are essentially related to solid fuels. Small modular reactors, two or three words on that. There have been, most of you know this on the newspapers, a proposal for going to reactors of much lower power between 10 and 300 megawatt electrical. One example which is here is the new scale project in the US. And what is claimed is that this reactor can shut down and continue to cooling itself indefinitely, even in a catastrophic event. These are intended to be kept below ground to absorb shocks of earthquakes, for example. And in the event of loss of power for the normal cooling system, the pool water begins to absorb heat and boil. This is one of the many ideas of this small reactor. This is a 60 megawatt electrical proposal in an advanced stage of design. However, there was an interesting study of MIT some time ago that pointed out what are the key points that make it difficult for nuclear to develop at present. They indicated four issues that you can imagine. Safety enhancement, the proliferation of resistance. They decreased the generation of waste. These are the requirements and cost reduction. These are the four parameters they said. These are essentially if you want to have a continuous development of nuclear energy. Now trade-offs between the desired feature and if one focus on one of them, one can have better effects on the other issues. And there was a study of the Columbia University which was, it's an example, of course. But there are reasons for all of that. They say, well, what if we look to these parameters and we look to different type of small modular reactors? For example, based on the technology of PWRs or HTR, the reactor at high temperature, molten soils or fast reactors or even nuclear batteries, very tiny reactors looking at their technical characteristics. And afterwards they looked to do the improved cost of safety, waste volume, and proliferation risk. They reduced the proliferation risk. This table here indicates the difficulty of coping and getting good results for all these parameters at the same time, even at the level of a small modular reactor. The safety is increased in a number of cases. The cost is practically all over increased. The waste volume, there are mixed impacts and the proliferation risk is often increased because of multiplying the facility which are implied by small modular reactors. This, to give you an idea that small modular reactors is a good idea, is worse to be thought and studied further, but it will not solve at all the full range of problems that can be associated to the development of nuclear energy. There have been studies in the US modifying the scenarios that have been indicated to you before introducing small modular reactors. What they have done is to say, well, let's make different hypotheses on the shutdown of the present fleet of reactors, licensing for 40 years, 60 years, or 80 years, so you will see disappearing them more in time. This is a scale where you have time. If you do the most 80 years licensing, you will be having, in the case of the US, the current fleet that will be disappearing starting from 2060 and will disappear in 2070 or whatever. What will be replacing it? Advanced light water reactors for the most part and what about the other options if we do not rely only on fast reactors and introduce them later on? The small modular reactors can cover part of the required increase in nuclear energy. The hypothesis here was what about if the US nuclear capacity will be doubling starting from 20, 30 years from now? How one will be coping? Advanced light water reactors will cover most of the needs, but up to the end of the century, fast reactor will be covering only part of that. Small modular reactors even deployed in a very fast way will be also covering only part of that with some further impact on resources. Last word on the traveling wave reactor of TerraPower. This is a reactor that will be using and improving the utilization of uranium up to a factor of 30 with respect to what is done in a PWR. The 1% goes up to 20, 30%. It's debatable if it's 20 or 30. And if one does that, it becomes interesting to think what about if I do not reprocess? I've got already a very large improvement in the utilization of uranium. Reprocessing will allow me to go much beyond that, but is it really necessary? And the effort, which is still going on and very seriously taken by other partners all over the world, in particular in China, is such that one can consider these benefits as very worthwhile to be taken into account by this type of reactor. No reprocessing plans, reduced number of enrichment plans because of the life of the traveling wave, reduced waste production, and less uranium ore to be mined because the use of the depleted uranium. In conclusion, well, innovative fuel cycle and the reactor concept can potentially help the optimization of waste management and improve it this way, the resource utilization. So it goes back to what we were saying yesterday. However, the fuel cycle issue are essentially in order to assess the feasibility and the economy or a specific strategy. Remember, the multiplication of fuel cycle installation that were needed if the scenario indicated yesterday were to be implemented. And in particular, where this facility should be deployed. There was an interesting option related to the increasing cooperative initiative that was indicated by Galina as an important issue. One can be optimistic about cooperation in strategic fields. I'm personally a little bit less optimistic. Now there are fuel reprocessing with very small losses in the transuranium recovery, which is mandatory. And this is not a little issue for chemists. The buildup of higher mass actinized like Curium, Berkelium, and California isotopes can be a very heavy burden in the fuel handling and fabrication, I've indicated that. And this should be very carefully investigated in practical application. And the multi-recycle is a key feature in any future cycle. We cannot hide the fact that any of this innovative fuel cycle relies on multi-recycle. Once through approach will only open the crucial issue related to the resource availability. And with that, I close and thank you for your attention.