Systemic competitiveness of nuclear energy sources

Possibilities are analyzed for improving the commercial attractiveness of nuclear electricity generation in market conditions. A model is presented in which a financially integrated electricity generating system comprising several units of one technological type, rather than a single unit, is subject to an economic analysis. Issues have been considered involved in the calculation of the electricity cost in such systems and their construction. It has been shown that the calculated unit cost of the electricity generated in a financially integrated nuclear energy system with the number of units being more than one, provided it is financed by shareholders and creditors, can be lower as compared with the cost of the electricity generated by power units, not integrated economically, of the same capacity under the same investment conditions. The effect is achieved thanks to the short-term crediting component in the electricity cost the funds on which can be returned, at a time, for a smaller number of units (even for only one), as electricity is produced by all units in the system. The results of the calculations for nuclear energy sources and combined-cycle plants using the developed model make it possible to conclude that the switch from economic models of individual nuclear units to models of integrated energy systems can bring the calculated economic performance of nuclear power closer to (or better) the performance of fossil-fuel energy sources. If achieved, this may increase the commercial attractiveness of nuclear power and contribute to a growth in the public and private investments in nuclear power business

Elaboration of approach to nuclear energy systems assessment by criterion of sustainable development

The paper describes the approach to the assessment of nuclear energy systems based on the integral indicator characterizing the level of their sustainability and results of comparative assessment of several nuclear energy system options incorporating different combinations of nuclear reactors and nuclear fuel cycle facilities. The nuclear energy systems are characterized by achievement of certain key events pertaining to the following six subject areas: economic performance, safety, availability of resources, waste handling, non-proliferation and public support. Achievement of certain key events is examined within the time interval until 2100, while the key events per se are assessed according to their contribution in the achievement of sustainable development goals. It was demonstrated that nuclear energy systems based on the once-through nuclear fuel cycle with thermal reactors and uranium oxide fuel do not score high according to the integral sustainable development indicator even in the case when the issue of isolation of spent nuclear fuel in geological formation is resolved. Gradual replacement of part of thermal reactors with fast reactors and closing the nuclear fuel cycle results in the achievement of evaluated characteristics in many subject areas, which are close to maximum requirements of sustainable development, and in the significant enhancement of the sustainability indicator

Multi-criteria evaluation and ranking of potential scenarios for the development of Russian two-component nuclear energy system with thermal and sodium-cooled fast reactors

The paper presents the results from a multi-criteria comparative evaluation of potential deployment scenarios for Russian nuclear power with thermal and sodium-cooled fast reactors in a closed nuclear fuel cycle (the so-called two-component nuclear energy system). The comparison and the ranking were performed taking into account the recommendations and using the IAEA/INPRO software tools for comparative evaluation of nuclear energy systems, including tools for sensitivity/uncertainty analysis with respect to weighting factors. Ten potential Russian nuclear power deployment scenarios with different shares of thermal and sodium-cooled fast reactors were considered, including options involving the use of MOX fuel in VVER reactors. Eight key indicators were used, estimated as of 2100 and structured into a three-level objectives tree. The comparative evaluation and the ranking were carried out based on the multi-attribute value theory. The model for assessing the key indicators was developed using the IAEA/INPRO MESSAGE-NES energy system planning software tool. The information base for the study was formed by publications of experts from JSC SSC RF-IPPE, NRC Kurchatov Institute and NRNU MEPhI. The presented results show that it is possible to enhance significantly the sustainability of the Russian nuclear energy system, when considering multiple performance indicators, through the intensive deployment of sodium-cooled fast reactors and the transition to a closed nuclear fuel cycle. Tasks have been outlined for the follow-up studies to make it possible to obtain more rigorous conclusions regarding the preferred options for the evolution of a two-component nuclear energy system

Some economic aspects of reducing americium production in a two-component system of thermal and fast reactors

The article analyzes the economic aspects of reducing the production of americium during the transition from a single-component nuclear energy system (NES) based on thermal reactors in an open fuel cycle to a two-component system with thermal and fast reactors in a closed nuclear fuel cycle. Scenarios for the development of these systems in Russia up to the end of the century are modeled. Two methods are considered for reducing the production of americium in a two-component NES with fast sodium reactors. The first method, closing the fuel cycle for plutonium in BN reactors of SFR type, is based on the use of plutonium separated from spent nuclear fuel of thermal reactors with the shortest possible (according to technical specifications) time for MOX fuel preparation and use thus preventing the main part of plutonium-241 from decay into americium. The second way is transmutation of americium. The study was carried out by using the mathematical code CYCLE designed for modeling of the NES with closed nuclear fuel cycle (NFC). The technical and economic data used in the paper was taken from published studies of Russian specialists and materials of European Union specialists presented in the IAEA/INPRO SYNERGIES project. The results of the research show that the efficiency of closing the NFC by using plutonium from thermal reactors in MOX fuel of fast sodium reactors is comparable to the efficiency of the homogeneous transmutation considered in the paper. The combination of the americium accumulation prevention method and transmutation method might significantly reduce the rate of the americium accumulation in a nuclear energy system, but the estimated costs of the considered homogeneous transmutation can significantly worsen the economic performance of sodium fast reactors

A high-Q low-dimensional resonator with electrically tunable frequency

A low-dimensional high-Q resonator has been proposed and its frequency-response characteristics have been investigated. The specified resonator features the frequency-response characteristics that are electrically tunable by using a semiconductor diode with variable capacitance

USE UNDERGROUND MINES FOR DISPOSAL OF RADIOACTIVE WASTE OF THE 3RD AND 4TH CLASSES

Link for citation: Gorin N.V., Kuchinov V.P., Usanov S.V., Vasiliev A.P. Use of underground mines for disposal of radioactive waste of the 3rd and 4th classes. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 128-136. In Rus. Relevance. Searching for the sites for radioactive waste disposal was carried out during the Soviet times and slowed down after the breakup of the USSR. It is proposed to return to the achieved results in this area and to get back to work on radioactive waste disposal site selection, since the disposal facilities for radioactive waste of the 3rd and 4th classes under construction will not be able to cope with the predicted amount of radioactive waste. Purpose: to offer as one of possible solutions, to use the free space of exhausted mines for the disposal of radioactive waste of the 3rd and 4th classes, including exhausted mines at the existing mining enterprises, and to consider the conditions of their use; to pay special attention to promoting public awareness, since public opinion may prevail over all other arguments. Subjects: exhausted and operating mines, accumulated amount of radioactive waste in the world and in Russia, selection of reliable sources of information, domestic experience of nuclear waste disposal in exhausted mines. Methods. The paper considers the possibilities of nuclear waste disposal from the viewpoint of current regulations and mine operation experience. Results. It is shown that waste handling necessitates public consultations and informing the population. Reliable sources of information on the amount of radioactive waste of different classes generated in the Russian Federation, as well as on their distribution by region and major enterprises are provided. It is noted that the amount of radioactive waste is two orders of magnitude less than that of municipal solid waste, but radioactive waste attracts more public attention in the media, and this should be taken into account when handling it, and organizing its storage and disposal

Multilateral assessment of the fast reactor system as a component of the future sustainable nuclear energy and paths for the system deployment

The paper reviews main findings of the Joint Assessment Study on a Nuclear Energy System (NES) based on a Closed Nuclear Fuel Cycle with Fast Reactors (CNFC-FRs) that was performed within the IAEA project INPRO

Magnetic frequency tuning of the microwave Gunn diode oscillator

It has been found experimentally that the oscillation frequency of a Gunn diode placed in the low-dimensional resonance system “metal pin–closely set short-circuiter” can be effectively controlled by magnetic field applied in the normal direction with respect to the waveguide wide wall

Unusual Cytochrome c552 from Thioalkalivibrio paradoxus: Solution NMR Structure and Interaction with Thiocyanate Dehydrogenase

The search of a putative physiological electron acceptor for thiocyanate dehydrogenase (TcDH) newly discovered in the thiocyanate-oxidizing bacteria Thioalkalivibrio paradoxus revealed an unusually large, single-heme cytochrome c (CytC552), which was co-purified with TcDH from the periplasm. Recombinant CytC552, produced in Escherichia coli as a mature protein without a signal peptide, has spectral properties similar to the endogenous protein and serves as an in vitro electron acceptor in the TcDH-catalyzed reaction. The CytC552 structure determined by NMR spectroscopy reveals significant differences compared to those of the typical class I bacterial cytochromes c: a high solvent accessible surface area for the heme group and so-called “intrinsically disordered” nature of the histidine-rich N- and C-terminal regions. Comparison of the signal splitting in the heteronuclear NMR spectra of oxidized, reduced, and TcDH-bound CytC552 reveals the heme axial methionine fluxionality. The TcDH binding site on the CytC552 surface was mapped using NMR chemical shift perturbations. Putative TcDH-CytC552 complexes were reconstructed by the information-driven docking approach and used for the analysis of effective electron transfer pathways. The best pathway includes the electron hopping through His528 and Tyr164 of TcDH, and His83 of CytC552 to the heme group in accordance with pH-dependence of TcDH activity with CytC552