# System Studies on the Fusion-Fission Hybrid Systems and Its Fuel Cycle
## 3 Results and Discussion
### FFHS in Two-Component Nuclear Power System of Russia and Its Potential for MA Reduction  
In the first part of this study, the potential of FFHSs for MA transmutation was defined. However, what also matters is the impact of FFHSs' operation on the nuclear power system that reduces the total amount of MA. For this purpose, the Universal System Model designed by [PERSON] [13] was used. This model describes the history and development plans of Russian nuclear power in terms of product flows (fuel, waste, energy, money) between important components of the system (power plants, fuel fabrication and reprocessing plants, consumers). The principal scheme of this model is shown in Figure 8. The model covers a period of time, from 1970 to 2130, and has the following features:  
* The two-component structure of nuclear power system for the 21 st century, i.e., there will be two types of reactors: thermal spectrum and fast spectrum
* Installed capacity of nuclear power plants in 2100 is 92 GW(e), and 107 GW(e) in 2130
* The accumulated amount of SNF from VVER is \(\sim\)5000 t
* VVER commissioning in Russia will end in 2040
* The export of nuclear power plants and their services are not taken into account  
Figure 9 shows the past and future planned evolution of the net installed capacity of nuclear power plants in Russia. In 2100, the last thermal reactor will be decommissioned and the system will consist of only fast reactors. Figure 8: Fusion neutron source in the structure of Russian nuclear power system (The Universal System Model). In this part of the investigation, some parameters of the FFHSs described above were decreased compared to the first part of this study: the total MA loading into the DEMO-FNS and PIHR blankets is 20 t and into IHR is 40 t. The efficiency of the actinides' incineration is slightly lower. The net installed capacity of nuclear power plants defines the total SNF (and hence MA) production, as well as the total accumulated amount of MA for a given year. This value defines the feasibility of a full blanket loading. The results presented here were obtained under the assumption that the blankets were fully loaded. For this, DEMO-FNS is decommissioned when PIHR is commissioned, while PIHR is decommissioned when IHR is commissioned. Figure 10 shows the total amount of minor actinides in the system at five-year intervals between 1970 and 2130. 287 t of MA are accumulated in SNF if there is no fuel reprocessing, as shown by the blue curve. The orange curve shows how this mass of actinides would be reduced by the means of hybrid reactors. The third curve describes the reduction of MA by the hybrid reactors' operation and the initial fuel loadings in the blankets, so it is possible to reduce the total amount by 28% (82 t) or 43% (122 t), taking into account the initial fuel loadings. Figure 10: Total inventory of MA in the system. Figure 9: Evolution of the net installed capacity of nuclear power plants in Russia. The production rate of minor actinides in the system was obtained based on information about MA accumulation during the assumed period of time (Figure 11). As follows from the graph it will be necessary to incinerate more than 4 t/year of MA at the end of this timeline. This means that at least 4 facilities with IHR parameters will be needed. Meanwhile, it is possible to take into commission just 2 additional IHRs in 2090 and 2120. In this case, it is possible to reduce the total amount by 48% (142 t) or 88% (262 t) taking into account the initial fuel loadings. It is not only the accumulated amount of minor actinides in SNF that is matter, but also the amount of minor actinides extracted in a given year during this timeline. The extracted amount is determined by the capabilities of Russia's reprocessing plants. This determines the feasibility of full fuel loading in the blanket. 20 t of MA are needed for the blanket's first loading. But only about 4 t of extracted MA at the start of DEMO-FNS in 2033, and 22 t in 2055, will be available.